feat(filter): per-directory merge rules at the receiver; implement e/n/w/- modifiers

src/client/client_manifest.c

@@ -330,9 +330,11 @@ int send_list_only(const Config* config) {
 }
 
 /* Send the delete manifest to the server.  Returns 0 on success, -1 on
-   failure.  It carries FOUR sections: the keep-set paths, the protected
+   failure.  It carries FOUR path sections (keep-set paths, protected excluded
-   excluded prefixes, the --delete-missing-args exact-delete paths, and the
+   prefixes, --delete-missing-args exact-delete paths, and the destination-
-   destination-relative directories the sender synchronized this run.
+   relative directories the sender synchronized this run) followed by the
+   protocol-2.30.0 per-directory filter-rule block (`per_dir_rules`, the rules
+   the scan compiled from each directory's merge files).
    When --delete-excluded is given `protected` is empty: excluded destination
    mirrors are then ordinary extras and are removed.  When
    --delete-missing-args is active `missing_args` holds the destination mirrors
@@ -346,7 +348,8 @@ int send_list_only(const Config* config) {
    frame.  A heavily filtered source whose exclusion list is large therefore
    fails the run cleanly on the receiver rather than being truncated. */
 int send_delete_manifest(int fd, ArrayList* manifest, ArrayList* protected_prefixes,
-                         ArrayList* size_skipped, ArrayList* missing_args, ArrayList* synced_dirs) {
+                         ArrayList* size_skipped, ArrayList* missing_args, ArrayList* synced_dirs,
+                         const FilterRuleList* per_dir_rules) {
   if (!send_status(fd, STATUS_MANIFEST))
     return -1;
   int keep_count = manifest ? manifest->size : 0;
@@ -389,6 +392,11 @@ int send_delete_manifest(int fd, ArrayList* manifest, ArrayList* protected_prefi
     if (!send_wire_str(fd, (char*)synced_dirs->items[i]))
       return -1;
   }
+  /* Protocol 2.30.0: the receiver-side per-directory filter rules discovered by
+     the sender's scan, so the whole-tree commit walker can shield a
+     destination-only entry that matches only a per-directory merge rule. */
+  if (!delete_filter_dir_rules_send(fd, per_dir_rules))
+    return -1;
   return 0;
 }
 
@@ -409,11 +417,11 @@ int send_delete_manifest(int fd, ArrayList* manifest, ArrayList* protected_prefi
 
 bool send_delete_manifest_early(Client* client, ArrayList* manifest, ArrayList* protected_prefixes,
                                 ArrayList* size_skipped, ArrayList* missing_args,
-                                ArrayList* synced_dirs) {
+                                ArrayList* synced_dirs, const FilterRuleList* per_dir_rules) {
   if (!client || !manifest)
     return false;
   if (send_delete_manifest(client->file_descriptor, manifest, protected_prefixes, size_skipped,
-                           missing_args, synced_dirs) != 0)
+                           missing_args, synced_dirs, per_dir_rules) != 0)
     return false;
   Status ack;
   /* The wait is long (up to an hour) and runs inline on this thread: a helper
@@ -497,6 +505,7 @@ int send_dry_run_remote(Config* config) {
   ArrayList* dry_dirs = NULL;
   ArrayList* dry_excluded = NULL;
   ArrayList* dry_size_skipped = NULL;
+  FilterRuleList* dry_per_dir = NULL;
   if (!config_send(client->file_descriptor, config))
     goto dry_fail;
   receive_daemon_motd(client, config);
@@ -509,8 +518,10 @@ int send_dry_run_remote(Config* config) {
     dry_manifest = array_list_create(free);
     dry_dirs = array_list_create(free);
     dry_size_skipped = array_list_create(free);
-    if (!dry_manifest || !dry_dirs || !dry_size_skipped)
+    dry_per_dir = filter_rule_list_create();
+    if (!dry_manifest || !dry_dirs || !dry_size_skipped || !dry_per_dir)
       goto dry_fail;
+    prepared.options.per_dir_rules = dry_per_dir;
     if (!config->delete_excluded) {
       dry_excluded = array_list_create(free);
       if (!dry_excluded)
@@ -612,7 +623,7 @@ int send_dry_run_remote(Config* config) {
   bool early_delete = config->use_delete && config_delete_timing_early(config);
   if (dry_manifest) {
     if (send_delete_manifest(client->file_descriptor, dry_manifest, dry_excluded, dry_size_skipped,
-                             NULL, dry_dirs) != 0)
+                             NULL, dry_dirs, dry_per_dir) != 0)
       goto dry_fail;
     if (early_delete) {
       Status ack;
@@ -672,6 +683,8 @@ dry_fail:
     array_list_delete(dry_excluded);
   if (dry_size_skipped)
     array_list_delete(dry_size_skipped);
+  if (dry_per_dir)
+    filter_rule_list_free(dry_per_dir);
   if (scanner)
     directory_scanner_destroy(scanner);
   prepared_scanner_destroy(&prepared);

src/client/client_send.c

@@ -1033,7 +1033,7 @@ static int send_chunks_multithreaded(void* pipeline_context) {
        and wait for the receiver to delete extras before streaming any data. */
     if (!send_delete_manifest_early(client, context->manifest, context->excluded_paths,
                                     context->size_skipped_paths, context->missing_args,
-                                    context->synced_dirs)) {
+                                    context->synced_dirs, context->per_dir_rules)) {
       pipeline_cancel(context);
       disconnect_transfer_client(client);
       mark_sender_done(context);
@@ -1163,7 +1163,8 @@ static int send_chunks_multithreaded(void* pipeline_context) {
       log_message(LOG_LEVEL_WARNING, "IO error encountered -- skipping file deletion");
     } else if (send_delete_manifest(client->file_descriptor, context->manifest,
                                     context->excluded_paths, context->size_skipped_paths,
-                                    context->missing_args, context->synced_dirs) != 0) {
+                                    context->missing_args, context->synced_dirs,
+                                    context->per_dir_rules) != 0) {
       goto send_fail;
     }
   } else if (context->config->delete_missing_args && !context->early_delete &&
@@ -1171,7 +1172,7 @@ static int send_chunks_multithreaded(void* pipeline_context) {
     /* --delete-missing-args without --delete: no keep-set is built, but the
        exact-delete paths still ride the same manifest frame (commit once the
        transfer succeeded). */
-    if (send_delete_manifest(client->file_descriptor, NULL, NULL, NULL, context->missing_args,
+    if (send_delete_manifest(client->file_descriptor, NULL, NULL, NULL, context->missing_args, NULL,
                              NULL) != 0)
       goto send_fail;
   }
@@ -1285,6 +1286,7 @@ static int scan_directory_multithreaded(void* pipeline_context) {
      its protected lists, so the data pass must not append to them again. */
   if (!context->early_delete && !context->delete_plans) {
     prepared.options.excluded_paths = context->excluded_paths;
+    prepared.options.per_dir_rules = context->per_dir_rules;
     /* The root marker for a full recursive transfer is already in the list; do
        not let the scanner append every directory to it. */
     if (context->config->files_from_set != NULL)
@@ -1518,6 +1520,8 @@ typedef struct {
   ArrayList* synced_dirs;
   ArrayList* plan_dirs;
   ArrayList* missing_args;
+  /* Per-directory filter rules compiled by the scan (protocol 2.30.0). */
+  FilterRuleList* per_dir_rules;
   PreparedScanner prepared;
   StopCondition stop;
   TransferStats transfer_stats;
@@ -1562,9 +1566,11 @@ static bool send_files_prepare(Config* config, SendFilesState* state) {
     }
     state->size_skipped = array_list_create(free);
     state->synced_dirs = array_list_create(free);
-    if (!state->size_skipped || !state->synced_dirs)
+    state->per_dir_rules = filter_rule_list_create();
+    if (!state->size_skipped || !state->synced_dirs || !state->per_dir_rules)
       return false;
     state->prepared.options.size_skipped_paths = state->size_skipped;
+    state->prepared.options.per_dir_rules = state->per_dir_rules;
     /* Only a --files-from subset confines the extras walk to the directories
        the scan synchronized; a full recursive transfer deletes throughout the
        receive root, so mark the root itself (the "." sentinel) and let the
@@ -1629,9 +1635,9 @@ static bool send_files_prepare_delete(Config* config, SendFilesState* state) {
         log_message(LOG_LEVEL_WARNING, "IO error encountered -- skipping file deletion");
         skip_delete = true;
       } else {
-        early_ok =
+        early_ok = send_delete_manifest_early(client, early_manifest, state->excluded,
-            send_delete_manifest_early(client, early_manifest, state->excluded, state->size_skipped,
+                                              state->size_skipped, state->missing_args,
-                                       state->missing_args, state->synced_dirs);
+                                              state->synced_dirs, state->per_dir_rules);
       }
     }
     array_list_delete(early_manifest);
@@ -1640,6 +1646,7 @@ static bool send_files_prepare_delete(Config* config, SendFilesState* state) {
     state->prepared.options.excluded_paths = NULL;
     state->prepared.options.size_skipped_paths = NULL;
     state->prepared.options.synced_dirs = NULL;
+    state->prepared.options.per_dir_rules = NULL;
     if (!prescan_ok || (!early_ok && !skip_delete)) {
       array_list_delete(prescan_chunks);
       return false;
@@ -1669,7 +1676,7 @@ static bool send_files_prepare_delete(Config* config, SendFilesState* state) {
           config->files_from_set ? state->synced_dirs : (walk_root ? state->synced_dirs : NULL);
       delete_plan_sender_finalize(state->plan_sender, scope, walk_root);
       delete_plan_sender_set_config(state->plan_sender, state->excluded, state->size_skipped,
-                                    state->missing_args);
+                                    state->missing_args, state->per_dir_rules);
       if (state->had_scan_io && delete_plan_sender_empty(state->plan_sender)) {
         log_message(LOG_LEVEL_ERROR,
                     "source scan hit an I/O error before finding any file; refusing to delete "
@@ -1693,6 +1700,7 @@ static bool send_files_prepare_delete(Config* config, SendFilesState* state) {
     state->prepared.options.size_skipped_paths = NULL;
     state->prepared.options.synced_dirs = NULL;
     state->prepared.options.plan_dirs = NULL;
+    state->prepared.options.per_dir_rules = NULL;
     if (!prescan_ok || (!plans_ok && !skip_delete))
       return false;
   } else if (config->use_delete) {
@@ -1874,7 +1882,8 @@ static int send_files_finalize(const Config* config, SendFilesState* state) {
          modes the deletion already went out with the data, so nothing is
          re-sent here. */
       if (send_delete_manifest(client->file_descriptor, state->manifest, state->excluded,
-                               state->size_skipped, state->missing_args, state->synced_dirs) != 0) {
+                               state->size_skipped, state->missing_args, state->synced_dirs,
+                               state->per_dir_rules) != 0) {
         if (state->manifest) {
           array_list_delete(state->manifest);
           state->manifest = NULL;
@@ -1949,6 +1958,8 @@ static void send_files_cleanup(SendFilesState* state) {
     array_list_delete(state->plan_dirs);
   if (state->missing_args)
     array_list_delete(state->missing_args);
+  if (state->per_dir_rules)
+    filter_rule_list_free(state->per_dir_rules);
   if (state->remove_sources)
     array_list_delete(state->remove_sources);
   if (state->dir_entries)
@@ -2130,7 +2141,8 @@ static int send_files_multithreaded_impl(Config* config) {
        confined; only a --files-from subset records concrete directories. */
     context->size_skipped_paths = array_list_create(free);
     context->synced_dirs = array_list_create(free);
-    if (!context->size_skipped_paths || !context->synced_dirs) {
+    context->per_dir_rules = filter_rule_list_create();
+    if (!context->size_skipped_paths || !context->synced_dirs || !context->per_dir_rules) {
       pipeline_context_sender_destroy(context);
       return 1;
     }
@@ -2159,6 +2171,7 @@ static int send_files_multithreaded_impl(Config* config) {
         if (context->excluded_paths)
           prepared.options.excluded_paths = context->excluded_paths;
         prepared.options.size_skipped_paths = context->size_skipped_paths;
+        prepared.options.per_dir_rules = context->per_dir_rules;
         /* The root marker for a full recursive transfer is already in the list;
            only a --files-from subset needs the scanner to record directories. */
         if (config->files_from_set != NULL)
@@ -2199,7 +2212,8 @@ static int send_files_multithreaded_impl(Config* config) {
                                                         : (walk_root ? context->synced_dirs : NULL);
         delete_plan_sender_finalize(context->delete_plans, scope, walk_root);
         delete_plan_sender_set_config(context->delete_plans, context->excluded_paths,
-                                      context->size_skipped_paths, context->missing_args);
+                                      context->size_skipped_paths, context->missing_args,
+                                      context->per_dir_rules);
       }
       bool empty = per_dir
                        ? (context->delete_plans && delete_plan_sender_empty(context->delete_plans))

src/client/client_send_internal.h

@@ -102,9 +102,10 @@ int send_dry_run_manifest(const Config* config);
 int send_list_only(const Config* config);
 int send_dry_run_remote(Config* config);
 int send_delete_manifest(int fd, ArrayList* manifest, ArrayList* protected_prefixes,
-                         ArrayList* size_skipped, ArrayList* missing_args, ArrayList* synced_dirs);
+                         ArrayList* size_skipped, ArrayList* missing_args, ArrayList* synced_dirs,
+                         const FilterRuleList* per_dir_rules);
 bool send_delete_manifest_early(Client* client, ArrayList* manifest, ArrayList* protected_prefixes,
                                 ArrayList* size_skipped, ArrayList* missing_args,
-                                ArrayList* synced_dirs);
+                                ArrayList* synced_dirs, const FilterRuleList* per_dir_rules);
 
 #endif

src/client/scanner.h

@@ -115,6 +115,13 @@ typedef struct {
    * directories, exactly like rsync; the receive root is the "." sentinel.
    * Guarded by `excluded_mutex`. */
   ArrayList* synced_dirs;
+  /* Per-directory filter-rule sink (optional): when non-NULL the scanner appends
+   * a deep copy of every rule it reads from a per-directory merge file, each
+   * carrying its owner directory and no-inherit flag (see filter.h).  The delete
+   * carriers transmit them so the receiver re-derives the per-directory
+   * protect/risk set for destination-only entries.  Guarded by `excluded_mutex`
+   * like the other sinks. */
+  FilterRuleList* per_dir_rules;
   /* Delete-plan directory sink (optional): when non-NULL the scanner appends
    * the destination-relative path of every directory it traverses (except the
    * receive root).  The per-directory --delete-during/--delete-delay plan

src/client/scanner_filter.c

@@ -511,13 +511,31 @@ FilterRuleList* read_dir_filters(const ScannerOptions* options, const char* dir_
   }
   if (base) {
     for (int i = 0; i < base->dir_merge_count; i++) {
-      if (!filter_file_append(own, dir_path, base->dir_merge_names[i], rel, &opts, &exists, err,
+      if (!filter_dir_merge_append(own, dir_path, &base->dir_merges[i], rel, &opts, &exists, err,
-                              err_size))
+                                   err_size))
         goto fail;
       if (exists && any_exists)
         *any_exists = true;
     }
   }
+  /* Mirror the directory's rules into the delete-carrier sink so the receiver
+   * can reconstruct its per-directory protect/risk set. */
+  if (options->per_dir_rules && own->count > 0) {
+    mtx_t* mtx = options->excluded_mutex;
+    if (mtx)
+      mtx_lock(mtx);
+    for (int i = 0; i < own->count; i++) {
+      FilterRule* copy = filter_rule_clone(own->items[i]);
+      if (!copy || !filter_rule_list_add(options->per_dir_rules, copy)) {
+        filter_rule_free(copy);
+        if (mtx)
+          mtx_unlock(mtx);
+        goto fail;
+      }
+    }
+    if (mtx)
+      mtx_unlock(mtx);
+  }
   return own;
 fail:
   filter_rule_list_free(own);

src/shared/delete.c

@@ -32,6 +32,19 @@ static bool keep_is_file(const PathIndex* index, const char* rel_path) {
   return path_index_contains(index, rel_path);
 }
 
+/* rsync's receiver-side verdict for one candidate extra: the per-directory
+ * chain first (deepest directory before ancestors), then the command-line base
+ * rules.  Either rule set may be absent. */
+FilterAction delete_protect_verdict(const DeleteProtectRules* protect, const char* rel_path,
+                                    const char* leaf, bool is_dir) {
+  if (!protect)
+    return FILTER_ACTION_NONE;
+  FilterAction action = filter_dir_rules_apply_side(protect->dir_rules, rel_path, leaf, is_dir);
+  if (action != FILTER_ACTION_NONE)
+    return action;
+  return filter_rules_apply_side(protect->base_rules, rel_path, leaf, is_dir, FILTER_SIDE_RECEIVER);
+}
+
 /* Classify a removed entry from its st_mode for the per-type delete counters. */
 DeleteEntryType delete_entry_type_of_mode(mode_t mode) {
   if (S_ISDIR(mode))
@@ -209,7 +222,7 @@ typedef struct {
 static bool delete_walk_fd(int dirfd, const char* rel_path, const PathIndex* keep,
                            const PathIndex* dirs, DeleteWalkState* state,
                            const DeleteSkipEntry* skips, int skip_count,
-                           const FilterRuleList* protect_rules, bool parent_deletable,
+                           const DeleteProtectRules* protect, bool parent_deletable,
                            bool* all_removed) {
   DeleteDirEntry* entries = NULL;
   size_t count = 0;
@@ -260,9 +273,8 @@ static bool delete_walk_fd(int dirfd, const char* rel_path, const PathIndex* kee
     if (path_under_skip_prefix(child_rel, at_root, skips, skip_count)) {
       shielded[i] = true;
       local_survives = true;
-    } else if (protect_rules &&
+    } else if (delete_protect_verdict(protect, child_rel, entries[i].name, entries[i].is_dir) ==
-               filter_rules_apply_side(protect_rules, child_rel, entries[i].name, entries[i].is_dir,
+               FILTER_ACTION_PROTECT) {
-                                       FILTER_SIDE_RECEIVER) == FILTER_ACTION_PROTECT) {
       /* A first-match protect rule shields the extra; for a directory the whole
          subtree is shielded (rsync prunes an excluded directory), so do not
          descend. */
@@ -293,7 +305,7 @@ static bool delete_walk_fd(int dirfd, const char* rel_path, const PathIndex* kee
     int childfd = openat(dirfd, entries[i].name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     bool child_all_removed = false;
     if (childfd >= 0) {
-      if (!delete_walk_fd(childfd, child_rel, keep, dirs, state, skips, skip_count, protect_rules,
+      if (!delete_walk_fd(childfd, child_rel, keep, dirs, state, skips, skip_count, protect,
                           deletable, &child_all_removed))
         operation_ok = false;
       close(childfd);
@@ -408,7 +420,7 @@ static bool delete_walk_fd(int dirfd, const char* rel_path, const PathIndex* kee
     int childfd = openat(dirfd, entries[i].name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     bool child_all_removed = false;
     if (childfd >= 0) {
-      if (!delete_walk_fd(childfd, child_rel, keep, dirs, state, skips, skip_count, protect_rules,
+      if (!delete_walk_fd(childfd, child_rel, keep, dirs, state, skips, skip_count, protect,
                           deletable, &child_all_removed))
         operation_ok = false;
       close(childfd);
@@ -443,7 +455,7 @@ static int open_destination_root(const char* dest_root) {
 
 bool delete_extras_list(const char* dest_root, const ArrayList* manifest,
                         const ArrayList* synced_dirs, const DeleteSkipEntry* skips, int skip_count,
-                        const FilterRuleList* protect_rules, ArrayList* out, size_t* count_out) {
+                        const DeleteProtectRules* protect, ArrayList* out, size_t* count_out) {
   if (count_out)
     *count_out = 0;
   if (!manifest || !out)
@@ -474,7 +486,7 @@ bool delete_extras_list(const char* dest_root, const ArrayList* manifest,
                            .observer = NULL,
                            .observer_context = NULL};
   bool ok = delete_walk_fd(rootfd, "", &keep, have_dirs ? &dirs : NULL, &state, skips, skip_count,
-                           protect_rules, false, &all_removed);
+                           protect, false, &all_removed);
   if (close(rootfd) != 0)
     ok = false;
   path_index_free(&keep);
@@ -488,7 +500,7 @@ bool delete_extras_list(const char* dest_root, const ArrayList* manifest,
 DeleteWalkResult delete_extras_limited_observed(const char* dest_root, const ArrayList* manifest,
                                                 const ArrayList* synced_dirs, size_t max_delete,
                                                 const DeleteSkipEntry* skips, int skip_count,
-                                                const FilterRuleList* protect_rules,
+                                                const DeleteProtectRules* protect,
                                                 size_t* deleted_out, size_t* skipped_out,
                                                 DeletePathObserver observer,
                                                 void* observer_context) {
@@ -527,7 +539,7 @@ DeleteWalkResult delete_extras_limited_observed(const char* dest_root, const Arr
                            .observer = observer,
                            .observer_context = observer_context};
   bool ok = delete_walk_fd(rootfd, "", &keep, have_dirs ? &dirs : NULL, &state, skips, skip_count,
-                           protect_rules, false, &all_removed);
+                           protect, false, &all_removed);
   if (close(rootfd) != 0)
     ok = false;
   path_index_free(&keep);
@@ -545,11 +557,10 @@ DeleteWalkResult delete_extras_limited_observed(const char* dest_root, const Arr
 DeleteWalkResult delete_extras_limited(const char* dest_root, const ArrayList* manifest,
                                        const ArrayList* synced_dirs, size_t max_delete,
                                        const DeleteSkipEntry* skips, int skip_count,
-                                       const FilterRuleList* protect_rules, size_t* deleted_out,
+                                       const DeleteProtectRules* protect, size_t* deleted_out,
                                        size_t* skipped_out) {
   return delete_extras_limited_observed(dest_root, manifest, synced_dirs, max_delete, skips,
-                                        skip_count, protect_rules, deleted_out, skipped_out, NULL,
+                                        skip_count, protect, deleted_out, skipped_out, NULL, NULL);
-                                        NULL);
 }
 
 bool delete_extras(const char* dest_root, const ArrayList* manifest) {

src/shared/delete.h

@@ -3,6 +3,7 @@
 
 #include "array_list.h"
 #include "config.h"
+#include "filter.h"
 #include <stdbool.h>
 #include <stddef.h>
 #include <sys/stat.h>
@@ -29,6 +30,24 @@ typedef enum {
   DELETE_WALK_ERROR
 } DeleteWalkResult;
 
+/* Receiver-side delete-protection rules for one walk.  `base_rules` is the
+ * command-line rule set the config frame carried (owner "" rules); `dir_rules`
+ * is the received per-directory rule set (rules carrying their owner directory
+ * and no-inherit flag).  Either may be NULL. */
+typedef struct {
+  const FilterRuleList* base_rules;
+  const FilterRuleList* dir_rules;
+} DeleteProtectRules;
+
+/* rsync's first-match-wins receiver verdict for one candidate extra: the
+ * per-directory chain is evaluated first (the containing directory's rules,
+ * then each ancestor's, then the receive root's), then the base rules.  Returns
+ * FILTER_ACTION_PROTECT when the entry is shielded by a receiver-side exclude,
+ * FILTER_ACTION_RISK when an include explicitly leaves it at risk, or
+ * FILTER_ACTION_NONE when no rule matched. */
+FilterAction delete_protect_verdict(const DeleteProtectRules* protect, const char* rel_path,
+                                    const char* leaf, bool is_dir);
+
 /* One protected entry for the delete walker.  When top_level_only is true the
    prefix is skipped only as a DIRECT child of dest_root (the --delay-updates
    staging directory, which must not hide genuine extras inside a nested
@@ -100,7 +119,7 @@ int delete_dir_entry_cmp_asc(const void* a, const void* b);
 DeleteWalkResult delete_extras_limited(const char* dest_root, const ArrayList* manifest,
                                        const ArrayList* synced_dirs, size_t max_delete,
                                        const DeleteSkipEntry* skips, int skip_count,
-                                       const FilterRuleList* protect_rules, size_t* deleted_out,
+                                       const DeleteProtectRules* protect, size_t* deleted_out,
                                        size_t* skipped_out);
 
 /* Entry kind of a removed path, reported to the delete observer so the receiver
@@ -124,14 +143,14 @@ DeleteEntryType delete_entry_type_of_mode(mode_t mode);
 
 /* `delete_extras_limited_observed` is delete_extras_limited with an optional
  * observer; the observer is invoked only for entries truly removed.  When
- * `protect_rules` is non-NULL its receiver-side verdict is evaluated for every
+ * `protect` is non-NULL its receiver-side verdict is evaluated for every
  * candidate extra: a first-match PROTECT leaves the entry (and, for a
  * directory, its whole subtree) in place, while RISK/NONE fall through to the
  * ordinary skip-prefix/keep-set logic. */
 DeleteWalkResult delete_extras_limited_observed(const char* dest_root, const ArrayList* manifest,
                                                 const ArrayList* synced_dirs, size_t max_delete,
                                                 const DeleteSkipEntry* skips, int skip_count,
-                                                const FilterRuleList* protect_rules,
+                                                const DeleteProtectRules* protect,
                                                 size_t* deleted_out, size_t* skipped_out,
                                                 DeletePathObserver observer,
                                                 void* observer_context);
@@ -142,7 +161,7 @@ DeleteWalkResult delete_extras_limited_observed(const char* dest_root, const Arr
    strings appended to `out` and receives their count in *count_out. */
 bool delete_extras_list(const char* dest_root, const ArrayList* manifest,
                         const ArrayList* synced_dirs, const DeleteSkipEntry* skips, int skip_count,
-                        const FilterRuleList* protect_rules, ArrayList* out, size_t* count_out);
+                        const DeleteProtectRules* protect, ArrayList* out, size_t* count_out);
 bool delete_extras(const char* dest_root, const ArrayList* manifest);
 
 /* Build the delete walk's skip-prefix set from the config's --delay-updates

src/shared/delete_commit.c

@@ -19,6 +19,7 @@
 #include "data.h"
 #include "delay_updates.h"
 #include "delete_commit.h"
+#include "delete_plan.h"
 #include "delta.h"
 #include "file.h"
 #include "format.h"
@@ -102,6 +103,13 @@ DeleteManifest* receive_manifest_entries(int fd) {
     delete_manifest_free(manifest);
     return NULL;
   }
+  /* Per-directory filter rules (protocol 2.30.0) follow the manifest sections
+   * with their own bounded self-describing format. */
+  if (!delete_filter_dir_rules_receive(fd, &manifest->per_dir_rules)) {
+    delete_manifest_free(manifest);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
   return manifest;
 }
 
@@ -112,6 +120,7 @@ void delete_manifest_free(DeleteManifest* manifest) {
   array_list_delete(manifest->protected);
   array_list_delete(manifest->missing);
   array_list_delete(manifest->dirs);
+  filter_rule_list_free(manifest->per_dir_rules);
   free(manifest);
 }
 
@@ -160,9 +169,11 @@ static bool delete_extras_budgeted_observed(const Config* config, const DeleteMa
     remaining = budget->max_delete - budget->deleted;
   size_t deleted = 0;
   size_t skipped = 0;
+  DeleteProtectRules protect = {.base_rules = config->protect_rules,
+                                .dir_rules = manifest->per_dir_rules};
   DeleteWalkResult result = delete_extras_limited_observed(
       config->receive_root_directory, manifest->keeps, manifest->dirs, remaining, skips.entries,
-      skips.count, config->protect_rules, &deleted, &skipped, observer, observer_context);
+      skips.count, &protect, &deleted, &skipped, observer, observer_context);
   delete_skips_free(&skips);
   budget->deleted += deleted;
   budget->skipped += skipped;
@@ -386,8 +397,10 @@ bool manifest_would_delete_list(const Config* config, const DeleteManifest* mani
   DeleteSkipSet skips;
   if (!delete_skips_build(config, manifest->protected, NULL, true, &skips))
     return false;
+  DeleteProtectRules protect = {.base_rules = config->protect_rules,
+                                .dir_rules = manifest->per_dir_rules};
   bool ok = delete_extras_list(config->receive_root_directory, manifest->keeps, manifest->dirs,
-                               skips.entries, skips.count, config->protect_rules, out, count_out);
+                               skips.entries, skips.count, &protect, out, count_out);
   delete_skips_free(&skips);
   return ok;
 }

src/shared/delete_commit.h

@@ -4,6 +4,7 @@
 #include "array_list.h"
 #include "config.h"
 #include "delete.h"
+#include "filter.h"
 #include <stdbool.h>
 
 /* Delete-commit module: delete-manifest receive plus the budgeted extras and
@@ -30,6 +31,13 @@ typedef struct DeleteManifest {
      leave untransmitted directories and the unlisted parts of listed ones
      alone, matching rsync's "delete only in synchronized directories". */
   ArrayList* dirs;
+  /* Per-directory filter rules the sender compiled while scanning (protocol
+     2.30.0), each carrying its owner directory and no-inherit flag.  The
+     receiver evaluates them (deepest before ancestors, then the command-line
+     base rules) against every candidate extra so a destination-only entry that
+     matches ONLY a per-directory `.rsync-filter`/dir-merge rule is shielded.
+     NULL when the sender transmitted none. */
+  FilterRuleList* per_dir_rules;
 } DeleteManifest;
 
 void delete_manifest_free(DeleteManifest* manifest);

src/shared/delete_plan.c

@@ -48,6 +48,7 @@ struct DeletePlanSender {
   const ArrayList* protected_prefixes;
   const ArrayList* size_skipped;
   const ArrayList* missing_args;
+  const FilterRuleList* per_dir_rules;
   size_t entries;
   /* Transmitted FILE entries only.  The caller's "empty scan" safety guard keys
      off this (an I/O error that hid every file must refuse to delete even when
@@ -284,12 +285,14 @@ bool delete_plan_sender_empty(const DeletePlanSender* sender) {
 }
 
 void delete_plan_sender_set_config(DeletePlanSender* sender, const ArrayList* protected_prefixes,
-                                   const ArrayList* size_skipped, const ArrayList* missing_args) {
+                                   const ArrayList* size_skipped, const ArrayList* missing_args,
+                                   const FilterRuleList* per_dir_rules) {
   if (!sender)
     return;
   sender->protected_prefixes = protected_prefixes;
   sender->size_skipped = size_skipped;
   sender->missing_args = missing_args;
+  sender->per_dir_rules = per_dir_rules;
 }
 
 /* True when `dir` is `root` itself or a descendant of it (path-component
@@ -320,6 +323,160 @@ static int send_str_section(int fd, const ArrayList* list) {
   return 0;
 }
 
+/* The directory a rule belongs to (its owner, or the transfer root for ""). */
+static const char* filter_dir_rule_owner(const FilterRule* rule) {
+  return (rule && rule->owner) ? rule->owner : "";
+}
+
+/* Transmit the received-side per-directory filter rules (protocol 2.30.0) as a
+ * self-describing list of directory groups: a group count, then for each group
+ * the relative owner directory followed by that directory's rule records (run
+ * order = the sender's traversal/rule order).  Rules of one directory are
+ * appended to the sink contiguously, so runs reproduce the compilation order.
+ * Bounded by MAX_FILTER_RULES / MAX_FILTER_BYTES and MAX_PROTECT_PATTERN_LEN so
+ * the peer never sees a frame it would reject. */
+bool delete_filter_dir_rules_send(int fd, const FilterRuleList* rules) {
+  int count = rules ? rules->count : 0;
+  if (count < 0 || count > MAX_FILTER_RULES) {
+    log_message(LOG_LEVEL_ERROR, "too many per-directory filter rules: %d (maximum %d)", count,
+                MAX_FILTER_RULES);
+    return false;
+  }
+  for (int i = 0; i < count; i++) {
+    const FilterRule* rule = rules->items[i];
+    size_t pattern_len = rule && rule->pattern ? strlen(rule->pattern) : 0;
+    if (!rule || !rule->pattern || pattern_len == 0 || pattern_len > MAX_PROTECT_PATTERN_LEN) {
+      log_message(LOG_LEVEL_ERROR, "invalid per-directory filter pattern");
+      return false;
+    }
+  }
+  int groups = 0;
+  for (int i = 0; i < count;) {
+    const char* owner = filter_dir_rule_owner(rules->items[i]);
+    groups++;
+    i++;
+    while (i < count && strcmp(filter_dir_rule_owner(rules->items[i]), owner) == 0)
+      i++;
+  }
+  if (!send_int(fd, groups))
+    return false;
+  for (int i = 0; i < count;) {
+    const char* owner = filter_dir_rule_owner(rules->items[i]);
+    int start = i;
+    i++;
+    while (i < count && strcmp(filter_dir_rule_owner(rules->items[i]), owner) == 0)
+      i++;
+    if (!send_wire_str(fd, owner) || !send_int(fd, i - start))
+      return false;
+    for (int j = start; j < i; j++) {
+      const FilterRule* rule = rules->items[j];
+      if (!send_int(fd, (int)rule->action) || !send_int(fd, (int)rule->sides) ||
+          !send_int(fd, rule->anchored ? 1 : 0) || !send_int(fd, rule->dir_only ? 1 : 0) ||
+          !send_int(fd, rule->negate ? 1 : 0) || !send_int(fd, rule->no_inherit ? 1 : 0) ||
+          !send_wire_str(fd, rule->pattern))
+        return false;
+    }
+  }
+  return true;
+}
+
+/* Read one wire flag (an int restricted to 0/1). */
+static bool receive_flag(int fd, bool* value) {
+  int raw;
+  if (!receive_int(fd, &raw) || (raw != 0 && raw != 1))
+    return false;
+  *value = raw != 0;
+  return true;
+}
+
+/* Read the per-directory filter block emitted by delete_filter_dir_rules_send.
+ * Reconstructs a flat FilterRuleList whose rules carry their owner directory;
+ * `*out` is NULL when the sender transmitted no rules.  Every bound is enforced
+ * (group/rule counts, owner/pattern bytes, pattern length, action/sides domain)
+ * so a malicious peer can neither overread nor allocate unboundedly.  Returns
+ * false on a malformed frame (the caller signals STATUS_ERROR). */
+bool delete_filter_dir_rules_receive(int fd, FilterRuleList** out) {
+  if (!out)
+    return false;
+  *out = NULL;
+  int groups;
+  if (!receive_int(fd, &groups) || groups < 0 || groups > MAX_FILTER_RULES)
+    return false;
+  if (groups == 0)
+    return true;
+  FilterRuleList* list = filter_rule_list_create();
+  if (!list)
+    return false;
+  int total_rules = 0;
+  size_t bytes = 0;
+  for (int g = 0; g < groups; g++) {
+    char* dir = receive_wire_str(fd);
+    if (!dir)
+      goto fail;
+    size_t dir_bytes = strlen(dir);
+    if (!(dir[0] == '\0' || (dir[0] != '/' && !has_path_traversal(dir))) ||
+        dir_bytes > MAX_FILTER_BYTES - bytes) {
+      free(dir);
+      goto fail;
+    }
+    bytes += dir_bytes;
+    int rule_count;
+    if (!receive_int(fd, &rule_count) || rule_count < 0 || rule_count > MAX_FILTER_RULES ||
+        rule_count > MAX_FILTER_RULES - total_rules) {
+      free(dir);
+      goto fail;
+    }
+    for (int r = 0; r < rule_count; r++) {
+      int action, sides;
+      bool anchored, dir_only, negate, no_inherit;
+      if (!receive_int(fd, &action) ||
+          (action != FILTER_ACTION_EXCLUDE && action != FILTER_ACTION_INCLUDE) ||
+          !receive_int(fd, &sides) || sides < (int)FILTER_SIDE_SENDER ||
+          sides > (int)(FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER) ||
+          !receive_flag(fd, &anchored) || !receive_flag(fd, &dir_only) ||
+          !receive_flag(fd, &negate) || !receive_flag(fd, &no_inherit)) {
+        free(dir);
+        goto fail;
+      }
+      char* pattern = receive_wire_str(fd);
+      size_t pattern_bytes = pattern ? strlen(pattern) : 0;
+      if (!pattern || pattern_bytes == 0 || pattern_bytes > MAX_PROTECT_PATTERN_LEN ||
+          pattern_bytes > MAX_FILTER_BYTES - bytes) {
+        free(pattern);
+        free(dir);
+        goto fail;
+      }
+      bytes += pattern_bytes;
+      FilterRule* rule = calloc(1, sizeof(FilterRule));
+      if (!rule) {
+        free(pattern);
+        free(dir);
+        goto fail;
+      }
+      rule->action = (FilterAction)action;
+      rule->sides = (unsigned)sides;
+      rule->anchored = anchored;
+      rule->dir_only = dir_only;
+      rule->negate = negate;
+      rule->no_inherit = no_inherit;
+      rule->owner = str_dup(dir);
+      rule->pattern = pattern;
+      if (!rule->owner || !filter_rule_list_add(list, rule)) {
+        filter_rule_free(rule);
+        free(dir);
+        goto fail;
+      }
+      total_rules++;
+    }
+    free(dir);
+  }
+  *out = list;
+  return true;
+fail:
+  filter_rule_list_free(list);
+  return false;
+}
+
 static int send_plan_node(int fd, DeletePlanSender* sender, PlanNode* node) {
   if (!send_status(fd, STATUS_DELETE_PLAN))
     return -1;
@@ -328,7 +485,8 @@ static int send_plan_node(int fd, DeletePlanSender* sender, PlanNode* node) {
   if (!sender->config_sent) {
     if (send_str_section(fd, sender->protected_prefixes) != 0 ||
         send_str_section(fd, sender->size_skipped) != 0 ||
-        send_str_section(fd, sender->missing_args) != 0)
+        send_str_section(fd, sender->missing_args) != 0 ||
+        !delete_filter_dir_rules_send(fd, sender->per_dir_rules))
       return -1;
     sender->config_sent = true;
   }
@@ -355,7 +513,8 @@ static int send_config_only(int fd, DeletePlanSender* sender) {
     return -1;
   if (send_str_section(fd, sender->protected_prefixes) != 0 ||
       send_str_section(fd, sender->size_skipped) != 0 ||
-      send_str_section(fd, sender->missing_args) != 0)
+      send_str_section(fd, sender->missing_args) != 0 ||
+      !delete_filter_dir_rules_send(fd, sender->per_dir_rules))
     return -1;
   sender->config_sent = true;
   if (!send_int(fd, 0)) /* apply = false */
@@ -472,6 +631,10 @@ struct DeletePlanSession {
   ArrayList* protected_prefixes;
   ArrayList* size_skipped;
   ArrayList* missing;
+  /* Received per-directory filter rules (protocol 2.30.0), or NULL.  Evaluated
+     deepest-directory-first for every candidate extra so a destination-only
+     entry matching only a per-directory rule is protected. */
+  FilterRuleList* per_dir_rules;
   ArrayList* deferred;
   DeletePathObserver observer;
   void* observer_context;
@@ -532,6 +695,7 @@ void delete_plan_session_destroy(DeletePlanSession* session) {
   array_list_delete(session->protected_prefixes);
   array_list_delete(session->size_skipped);
   array_list_delete(session->missing);
+  filter_rule_list_free(session->per_dir_rules);
   array_list_delete(session->deferred);
   free(session);
 }
@@ -604,16 +768,18 @@ static int open_plan_dir(const Config* config, const char* dir) {
 
 typedef struct {
   DeleteSkipSet set;
-  /* Receiver-side delete-protection rules received on the config frame (NULL
+  /* Receiver-side delete-protection rules.  `base` is the config-frame
-     when the sender sent none).  Evaluated per extra so a protect/risk rule is
+     command-line set and `dir` the received per-directory set (both NULL when
+     the sender sent none).  Evaluated per extra so a protect/risk rule is
      honored under --delete-during/--delete-delay exactly like the whole-tree
      commit walker. */
-  const FilterRuleList* protect_rules;
+  DeleteProtectRules protect;
 } PlanSkips;
 
 static bool build_plan_skips(const Config* config, const DeletePlanSession* session,
                              PlanSkips* out) {
-  out->protect_rules = config->protect_rules;
+  out->protect.base_rules = config->protect_rules;
+  out->protect.dir_rules = session->per_dir_rules;
   /* The per-directory plan walk keeps each basis path verbatim (it does not
      convert an absolute under-root path to its root-relative form, unlike the
      whole-tree commit walk). */
@@ -778,10 +944,8 @@ static bool process_children(int dirfd, const char* dir_rel, const ArrayList* ke
     bool is_dir = entries[i].is_dir;
     bool in_keep_dirs = is_dir && list_contains_str(keep_dirs, entries[i].name);
     bool in_keep_files = !is_dir && list_contains_str(keep_files, entries[i].name);
-    bool rule_protected =
+    bool rule_protected = delete_protect_verdict(&skips->protect, child_rel, entries[i].name,
-        skips->protect_rules &&
+                                                 is_dir) == FILTER_ACTION_PROTECT;
-        filter_rules_apply_side(skips->protect_rules, child_rel, entries[i].name, is_dir,
-                                FILTER_SIDE_RECEIVER) == FILTER_ACTION_PROTECT;
     if (in_keep_dirs || in_keep_files || rule_protected) {
       shielded[i] = true;
       local_survives = true;
@@ -903,7 +1067,8 @@ int delete_plan_session_receive(DeletePlanSession* session, const Config* config
   if (has_config) {
     if (session->config_seen || !read_section(fd, session->protected_prefixes, true, &bytes) ||
         !read_section(fd, session->size_skipped, true, &bytes) ||
-        !read_section(fd, session->missing, true, &bytes)) {
+        !read_section(fd, session->missing, true, &bytes) ||
+        !delete_filter_dir_rules_receive(fd, &session->per_dir_rules)) {
       send_status(fd, STATUS_ERROR);
       return -1;
     }

src/shared/delete_plan.h

@@ -25,6 +25,19 @@
  * --delete-missing-args exact deletions, the shared --max-delete budget and,
  * for --delete-delay, the snapshotted extras. */
 
+/* Per-directory filter-rule block (protocol 2.30.0).  The sender compiles the
+ * source's per-directory merge rules as it scans and streams them so the
+ * receiver can re-derive the receiver-side protect/risk verdicts for
+ * destination-only entries.  The wire format is a group count, then for each
+ * directory group its relative owner path followed by that directory's rule
+ * records (action, sides, anchored, dir-only, negate, no-inherit, pattern).
+ * All bounds (MAX_FILTER_RULES, MAX_FILTER_BYTES, MAX_PROTECT_PATTERN_LEN) are
+ * enforced on both sides; a malformed receive frame signals STATUS_ERROR and
+ * returns false.  Receive yields a flat FilterRuleList whose rules carry their
+ * owner, or NULL when no rules were sent. */
+bool delete_filter_dir_rules_send(int fd, const FilterRuleList* rules);
+bool delete_filter_dir_rules_receive(int fd, FilterRuleList** out);
+
 /* ---- Sender: plan builder ---- */
 
 typedef struct DeletePlanSender DeletePlanSender;
@@ -53,7 +66,8 @@ bool delete_plan_sender_empty(const DeletePlanSender* sender);
  * block is always transmitted by delete_plan_send_root(), on a config-only
  * carrier frame when the scope allows no directory plan. */
 void delete_plan_sender_set_config(DeletePlanSender* sender, const ArrayList* protected_prefixes,
-                                   const ArrayList* size_skipped, const ArrayList* missing_args);
+                                   const ArrayList* size_skipped, const ArrayList* missing_args,
+                                   const FilterRuleList* per_dir_rules);
 /* Send the root plan (even before any data, so root extras are handled like
  * rsync's first generator directory), after transmitting the per-run config
  * block on its own carrier frame.  Returns -1 on I/O error. */

src/shared/filter.c

@@ -11,6 +11,8 @@
 /* Write a diagnostic message into the caller's optional buffer. */
 #define filter_set_error utils_set_error
 
+static bool set_rule_owner(FilterRule* rule, const char* owner);
+
 /* ---- Ordered rule lists ---- */
 
 void filter_rule_free(FilterRule* rule) {
@@ -21,6 +23,28 @@ void filter_rule_free(FilterRule* rule) {
   free(rule);
 }
 
+FilterRule* filter_rule_clone(const FilterRule* rule) {
+  if (!rule)
+    return NULL;
+  FilterRule* copy = calloc(1, sizeof(FilterRule));
+  if (!copy)
+    return NULL;
+  copy->action = rule->action;
+  copy->sides = rule->sides;
+  copy->anchored = rule->anchored;
+  copy->dir_only = rule->dir_only;
+  copy->negate = rule->negate;
+  copy->perishable = rule->perishable;
+  copy->no_inherit = rule->no_inherit;
+  copy->owner = str_dup(rule->owner ? rule->owner : "");
+  copy->pattern = str_dup(rule->pattern ? rule->pattern : "");
+  if (!copy->owner || !copy->pattern) {
+    filter_rule_free(copy);
+    return NULL;
+  }
+  return copy;
+}
+
 FilterRuleList* filter_rule_list_create(void) {
   return calloc(1, sizeof(FilterRuleList));
 }
@@ -48,33 +72,76 @@ void filter_rule_list_free(FilterRuleList* list) {
   for (int i = 0; i < list->count; i++)
     filter_rule_free(list->items[i]);
   for (int i = 0; i < list->dir_merge_count; i++)
-    free(list->dir_merge_names[i]);
+    free(list->dir_merges[i].name);
-  free(list->dir_merge_names);
+  free(list->dir_merges);
   free(list->items);
   free(list);
 }
 
+/* Append an implicit exclude rule for the merge file itself (rsync's 'e'
+ * modifier).  The rule is owned by the transfer root and matches the basename
+ * anywhere, exactly like rsync's EXCLUDE_SELF (a dual-sided exclude: it hides
+ * the file and protects its destination mirror from --delete). */
+static bool filter_list_add_exclude_self(FilterRuleList* list, const char* name) {
+  const char* base = strrchr(name, '/');
+  base = base ? base + 1 : name;
+  if (base[0] == '\0')
+    return true;
+  FilterRule* rule = calloc(1, sizeof(FilterRule));
+  if (!rule)
+    return false;
+  rule->action = FILTER_ACTION_EXCLUDE;
+  rule->sides = FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER;
+  rule->pattern = str_dup(base);
+  if (!rule->pattern || !set_rule_owner(rule, "")) {
+    filter_rule_free(rule);
+    return false;
+  }
+  if (!filter_rule_list_add(list, rule)) {
+    filter_rule_free(rule);
+    return false;
+  }
+  return true;
+}
+
 /* Register a per-directory merge-file basename (for "dir-merge NAME"/": NAME"
  * and -F's .rsync-filter).  Duplicate names are ignored. */
 bool filter_rule_list_add_dir_merge(FilterRuleList* list, const char* name) {
+  return filter_rule_list_add_dir_merge_ex(list, name, false, false, false, false, false);
+}
+
+bool filter_rule_list_add_dir_merge_ex(FilterRuleList* list, const char* name, bool no_prefixes,
+                                       bool include, bool word_split, bool no_inherit,
+                                       bool exclude_self) {
   if (!list || !name || name[0] == '\0')
     return false;
   for (int i = 0; i < list->dir_merge_count; i++) {
-    if (strcmp(list->dir_merge_names[i], name) == 0)
+    if (strcmp(list->dir_merges[i].name, name) == 0)
       return true;
   }
   if (list->dir_merge_count == list->dir_merge_capacity) {
     int new_cap = list->dir_merge_capacity > 0 ? list->dir_merge_capacity * 2 : 4;
-    char** grown = realloc(list->dir_merge_names, (size_t)new_cap * sizeof(char*));
+    FilterDirMerge* grown = realloc(list->dir_merges, (size_t)new_cap * sizeof(*grown));
     if (!grown)
       return false;
-    list->dir_merge_names = grown;
+    list->dir_merges = grown;
     list->dir_merge_capacity = new_cap;
   }
   char* dup = str_dup(name);
   if (!dup)
     return false;
-  list->dir_merge_names[list->dir_merge_count++] = dup;
+  if (exclude_self && !filter_list_add_exclude_self(list, name)) {
+    free(dup);
+    return false;
+  }
+  FilterDirMerge* entry = &list->dir_merges[list->dir_merge_count];
+  entry->name = dup;
+  entry->no_prefixes = no_prefixes;
+  entry->include = include;
+  entry->word_split = word_split;
+  entry->no_inherit = no_inherit;
+  entry->exclude_self = exclude_self;
+  list->dir_merge_count++;
   return true;
 }
 
@@ -177,10 +244,11 @@ static bool is_unsupported_modifier_char(char c) {
   return c == 'e' || c == 'n' || c == 'w';
 }
 
-/* Merge-file modifiers rsync accepts on merge/dir-merge rules: 'e', 'n', 'w'
+/* Merge-file modifiers rsync accepts on merge/dir-merge rules: 'e' (exclude
- * and '-' (do not transfer the merge file). */
+ * self), 'n' (no inherit), 'w' (word split), '-' (bare excludes) and '+'
+ * (bare includes). */
 static bool is_merge_modifier_char(char c) {
-  return c == 'e' || c == 'n' || c == 'w' || c == '-';
+  return c == 'e' || c == 'n' || c == 'w' || c == '-' || c == '+';
 }
 
 /* Characters that count as part of a modifier run for `kind` when deciding
@@ -228,8 +296,10 @@ static char unsupported_modifier_in_token(const char* tok, RuleKind kind) {
  * generic syntax error so callers can emit a precise diagnostic. */
 static bool parse_rule_syntax(const char* text, RuleKind* kind, unsigned* sides,
                               bool* sides_explicit, bool* negate, bool* anchored_mod,
-                              bool* perishable, bool* xattr, bool* cvs_inject,
+                              bool* perishable, bool* xattr, bool* cvs_inject, bool* no_prefixes,
-                              const char** pat_start, size_t* pat_len, char* bad_mod) {
+                              bool* include_defaults, bool* word_split, bool* no_inherit,
+                              bool* exclude_self, const char** pat_start, size_t* pat_len,
+                              char* bad_mod) {
   const char* p = text;
   *sides = FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER;
   *sides_explicit = false;
@@ -238,6 +308,11 @@ static bool parse_rule_syntax(const char* text, RuleKind* kind, unsigned* sides,
   *perishable = false;
   *xattr = false;
   *cvs_inject = false;
+  *no_prefixes = false;
+  *include_defaults = false;
+  *word_split = false;
+  *no_inherit = false;
+  *exclude_self = false;
   *pat_start = NULL;
   *pat_len = 0;
   *bad_mod = '\0';
@@ -312,6 +387,21 @@ static bool parse_rule_syntax(const char* text, RuleKind* kind, unsigned* sides,
     case 'C':
       *cvs_inject = true;
       break;
+    case '-':
+      *no_prefixes = true;
+      break;
+    case '+':
+      *include_defaults = true;
+      break;
+    case 'e':
+      *exclude_self = true;
+      break;
+    case 'n':
+      *no_inherit = true;
+      break;
+    case 'w':
+      *word_split = true;
+      break;
     default:
       break;
     }
@@ -347,11 +437,13 @@ FilterRule* filter_rule_parse(const char* line, const FilterParseOptions* opts,
   RuleKind kind = RULE_KIND_UNKNOWN;
   unsigned sides;
   bool sides_explicit, negate, anchored_mod, perishable, xattr, cvs_inject;
+  bool no_prefixes, include_defaults, word_split, no_inherit, exclude_self;
   const char* pat;
   size_t pat_len;
   char bad_mod;
   if (!parse_rule_syntax(p, &kind, &sides, &sides_explicit, &negate, &anchored_mod, &perishable,
-                         &xattr, &cvs_inject, &pat, &pat_len, &bad_mod)) {
+                         &xattr, &cvs_inject, &no_prefixes, &include_defaults, &word_split,
+                         &no_inherit, &exclude_self, &pat, &pat_len, &bad_mod)) {
     if (bad_mod != '\0')
       filter_set_error(err, err_size, "unsupported filter modifier '%c'", bad_mod);
     else
@@ -522,16 +614,130 @@ static bool filter_list_parse_append_depth(FilterRuleList* list, const char* lin
                                            const FilterParseOptions* opts, const char* base_dir,
                                            int depth, char* err, size_t err_size);
 
-/* Read a merge file and splice its rules into `list`.  A relative path is
+/* Append one merge-file token/line to `list`, honoring the merge rule's
- * resolved below `base_dir` when given, else used as-is (rsync resolves a
+ * no-prefix/include mode.  In no-prefix mode the token is a bare pattern whose
- * command-line merge file relative to the current directory). */
+ * include/exclude default comes from the merge rule (rsync's "-"/"+" merge
+ * modifiers); otherwise the token is parsed as a full filter rule. */
+static bool filter_merge_append_token(FilterRuleList* list, const char* token,
+                                      const FilterDirMerge* spec, const FilterParseOptions* opts,
+                                      const char* base_dir, int depth, char* err, size_t err_size) {
+  if (spec->no_prefixes || spec->include) {
+    size_t tlen = strlen(token);
+    char* text = malloc(tlen + 3);
+    if (!text) {
+      filter_set_error(err, err_size, "memory allocation failed");
+      return false;
+    }
+    text[0] = spec->include ? '+' : '-';
+    text[1] = ' ';
+    memcpy(text + 2, token, tlen + 1);
+    bool ok = filter_list_parse_append_depth(list, text, opts, base_dir, depth + 1, err, err_size);
+    free(text);
+    return ok;
+  }
+  return filter_list_parse_append_depth(list, token, opts, base_dir, depth + 1, err, err_size);
+}
+
+/* Read a merge file's tokens/lines into `list` for `spec`.  A `w` merge rule
+ * word-splits on whitespace (turning comments off); otherwise lines are parsed
+ * and whole-line `#` comments skipped.  When `owner_rel` is non-NULL the newly
+ * added rules are owned by that directory; a no-inherit spec marks them so they
+ * apply only there.  Returns false on parse/allocation failure. */
+static bool filter_merge_read(FilterRuleList* list, FILE* fp, const char* display_path,
+                              const FilterDirMerge* spec, const FilterParseOptions* opts,
+                              const char* base_dir, const char* owner_rel, int depth, char* err,
+                              size_t err_size) {
+  int rules_before = list->count;
+  char* line = NULL;
+  size_t cap = 0;
+  bool ok = true;
+  while (ok) {
+    ssize_t n = utils_getdelim_bounded(fp, &line, &cap, '\n', UTILS_MAX_LINE_LEN);
+    if (n < 0) {
+      if (errno == EFBIG)
+        filter_set_error(err, err_size, "line in %s exceeds %d bytes", display_path,
+                         (int)UTILS_MAX_LINE_LEN);
+      else
+        filter_set_error(err, err_size, "error reading %s: %s", display_path, strerror(errno));
+      ok = false;
+      break;
+    }
+    if (n == 0)
+      break;
+    if (spec->word_split) {
+      /* Whitespace-separated tokens; newlines are ordinary separators and
+       * comments are disabled. */
+      const char* s = line;
+      while (*s) {
+        while (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r')
+          s++;
+        if (*s == '\0')
+          break;
+        const char* start = s;
+        while (*s != '\0' && *s != ' ' && *s != '\t' && *s != '\n' && *s != '\r')
+          s++;
+        size_t tlen = (size_t)(s - start);
+        char* token = malloc(tlen + 1);
+        if (!token) {
+          filter_set_error(err, err_size, "memory allocation failed");
+          ok = false;
+          break;
+        }
+        memcpy(token, start, tlen);
+        token[tlen] = '\0';
+        if (!filter_merge_append_token(list, token, spec, opts, base_dir, depth, err, err_size))
+          ok = false;
+        free(token);
+      }
+    } else {
+      const char* lp = line;
+      while (*lp == ' ' || *lp == '\t')
+        lp++;
+      if (*lp == '\0' || *lp == '\n' || *lp == '\r' || *lp == '#')
+        continue;
+      if (!filter_merge_append_token(list, lp, spec, opts, base_dir, depth, err, err_size))
+        ok = false;
+    }
+  }
+  free(line);
+  if (!ok) {
+    /* Drop the rules this read appended (a "clear" inside the file may have
+     * freed earlier rules too; clamp like filter_file_rollback). */
+    int first = rules_before < list->count ? rules_before : list->count;
+    for (int i = first; i < list->count; i++)
+      filter_rule_free(list->items[i]);
+    list->count = first;
+    return false;
+  }
+  for (int i = rules_before; i < list->count; i++) {
+    FilterRule* rule = list->items[i];
+    if (spec->no_inherit)
+      rule->no_inherit = true;
+    if (owner_rel && !set_rule_owner(rule, owner_rel)) {
+      filter_set_error(err, err_size, "memory allocation failed");
+      for (int j = rules_before; j < list->count; j++)
+        filter_rule_free(list->items[j]);
+      list->count = rules_before;
+      return false;
+    }
+  }
+  return true;
+}
+
+/* Read a single-instance merge file and splice its rules into `list`.  A
+ * relative path is resolved below `base_dir` when given, else used as-is (rsync
+ * resolves a command-line merge file relative to the current directory). */
 static bool filter_list_merge_file(FilterRuleList* list, const char* name,
-                                   const FilterParseOptions* opts, const char* base_dir, int depth,
+                                   const FilterDirMerge* spec, const FilterParseOptions* opts,
-                                   char* err, size_t err_size) {
+                                   const char* base_dir, int depth, char* err, size_t err_size) {
   if (name[0] == '\0') {
     filter_set_error(err, err_size, "merge requires a filename");
     return false;
   }
+  if (spec->exclude_self && !filter_list_add_exclude_self(list, name)) {
+    filter_set_error(err, err_size, "memory allocation failed");
+    return false;
+  }
   char* path =
       (base_dir && base_dir[0] && name[0] != '/') ? path_cat(base_dir, name) : str_dup(name);
   if (!path) {
@@ -544,29 +750,7 @@ static bool filter_list_merge_file(FilterRuleList* list, const char* name,
     free(path);
     return false;
   }
-  char* line = NULL;
+  bool ok = filter_merge_read(list, fp, path, spec, opts, base_dir, NULL, depth, err, err_size);
-  size_t cap = 0;
-  bool ok = true;
-  while (true) {
-    ssize_t n = utils_getdelim_bounded(fp, &line, &cap, '\n', UTILS_MAX_LINE_LEN);
-    if (n < 0) {
-      filter_set_error(err, err_size, "error reading merge file '%s'", path);
-      ok = false;
-      break;
-    }
-    if (n == 0)
-      break;
-    const char* lp = line;
-    while (*lp == ' ' || *lp == '\t')
-      lp++;
-    if (*lp == '\0' || *lp == '\n' || *lp == '\r' || *lp == '#')
-      continue;
-    if (!filter_list_parse_append_depth(list, lp, opts, base_dir, depth + 1, err, err_size)) {
-      ok = false;
-      break;
-    }
-  }
-  free(line);
   fclose(fp);
   free(path);
   return ok;
@@ -590,11 +774,13 @@ static bool filter_list_parse_append_depth(FilterRuleList* list, const char* lin
   RuleKind kind = RULE_KIND_UNKNOWN;
   unsigned sides;
   bool sides_explicit, negate, anchored_mod, perishable, xattr, cvs_inject;
+  bool no_prefixes, include_defaults, word_split, no_inherit, exclude_self;
   const char* pat;
   size_t pat_len;
   char bad_mod;
   if (!parse_rule_syntax(p, &kind, &sides, &sides_explicit, &negate, &anchored_mod, &perishable,
-                         &xattr, &cvs_inject, &pat, &pat_len, &bad_mod)) {
+                         &xattr, &cvs_inject, &no_prefixes, &include_defaults, &word_split,
+                         &no_inherit, &exclude_self, &pat, &pat_len, &bad_mod)) {
     if (bad_mod != '\0')
       filter_set_error(err, err_size, "unsupported filter modifier '%c': %s", bad_mod, p);
     else
@@ -640,7 +826,15 @@ static bool filter_list_parse_append_depth(FilterRuleList* list, const char* lin
     }
     memcpy(name, pat, pat_len);
     name[pat_len] = '\0';
-    bool ok = filter_list_merge_file(list, name, opts, base_dir, depth, err, err_size);
+    /* A single-instance merge has no inheritance, so 'n' is meaningless; the
+     * other merge modifiers still shape how the file is read. */
+    FilterDirMerge spec = {.name = name,
+                           .no_prefixes = no_prefixes,
+                           .include = include_defaults,
+                           .word_split = word_split,
+                           .no_inherit = false,
+                           .exclude_self = exclude_self};
+    bool ok = filter_list_merge_file(list, name, &spec, opts, base_dir, depth, err, err_size);
     free(name);
     return ok;
   }
@@ -656,7 +850,8 @@ static bool filter_list_parse_append_depth(FilterRuleList* list, const char* lin
     }
     memcpy(name, pat, pat_len);
     name[pat_len] = '\0';
-    bool ok = filter_rule_list_add_dir_merge(list, name);
+    bool ok = filter_rule_list_add_dir_merge_ex(list, name, no_prefixes, include_defaults,
+                                                word_split, no_inherit, exclude_self);
     free(name);
     if (!ok) {
       filter_set_error(err, err_size, "memory allocation failed");
@@ -714,6 +909,10 @@ FilterRuleList* filter_base_build(const char* const* rule_texts, int rule_count,
 
 /* ---- Per-directory merge files ---- */
 
+/* Undo the rules and dir-merge registrations that one merge file appended,
+ * leaving the caller's earlier content intact.  A "clear" rule inside the file
+ * frees every rule, including the caller's; clamp to the surviving count so
+ * those already-freed rules are never resurrected and freed a second time. */
 /* Undo the rules and dir-merge registrations that one merge file appended,
  * leaving the caller's earlier content intact.  A "clear" rule inside the file
  * frees every rule, including the caller's; clamp to the surviving count so
@@ -724,20 +923,20 @@ static void filter_file_rollback(FilterRuleList* list, int rules_before, int dir
     filter_rule_free(list->items[i]);
   list->count = first;
   for (int i = dir_merges_before; i < list->dir_merge_count; i++)
-    free(list->dir_merge_names[i]);
+    free(list->dir_merges[i].name);
   list->dir_merge_count = dir_merges_before;
 }
 
-bool filter_file_append(FilterRuleList* list, const char* dir_path, const char* name,
+bool filter_dir_merge_append(FilterRuleList* list, const char* dir_path, const FilterDirMerge* spec,
-                        const char* owner_rel, const FilterParseOptions* opts, bool* exists,
+                             const char* owner_rel, const FilterParseOptions* opts, bool* exists,
-                        char* err, size_t err_size) {
+                             char* err, size_t err_size) {
   if (err && err_size > 0)
     err[0] = '\0';
   if (exists)
     *exists = false;
-  if (!list)
+  if (!list || !spec || !spec->name)
     return false;
-  char* filter_path = path_cat(dir_path, name);
+  char* filter_path = path_cat(dir_path, spec->name);
   if (!filter_path) {
     filter_set_error(err, err_size, "memory allocation failed");
     return false;
@@ -748,7 +947,7 @@ bool filter_file_append(FilterRuleList* list, const char* dir_path, const char*
     if (errno == ENOENT || errno == ENOTDIR)
       return true;
     char* escaped_dir = output_escape(dir_path, log_get_8_bit_output());
-    log_message(LOG_LEVEL_WARNING, "Could not read %s in %s: %s", name,
+    log_message(LOG_LEVEL_WARNING, "Could not read %s in %s: %s", spec->name,
                 escaped_dir ? escaped_dir : "<allocation failed>", strerror(errno));
     free(escaped_dir);
     return true;
@@ -757,51 +956,25 @@ bool filter_file_append(FilterRuleList* list, const char* dir_path, const char*
     *exists = true;
   int rules_before = list->count;
   int dir_merges_before = list->dir_merge_count;
-  char* line = NULL;
+  /* Merge files inside a per-directory file resolve relative to that
-  size_t line_cap = 0;
+     directory. */
-  bool ok = true;
+  bool ok =
-  while (true) {
+      filter_merge_read(list, fp, spec->name, spec, opts, dir_path, owner_rel, 0, err, err_size);
-    ssize_t n = utils_getdelim_bounded(fp, &line, &line_cap, '\n', UTILS_MAX_LINE_LEN);
-    if (n < 0) {
-      if (errno == EFBIG) {
-        filter_set_error(err, err_size, "line in %s exceeds %d bytes", name,
-                         (int)UTILS_MAX_LINE_LEN);
-      } else {
-        filter_set_error(err, err_size, "error reading %s: %s", name, strerror(errno));
-      }
-      ok = false;
-      break;
-    }
-    if (n == 0)
-      break;
-    const char* p = line;
-    while (*p == ' ' || *p == '\t')
-      p++;
-    if (*p == '\0' || *p == '\n' || *p == '\r' || *p == '#')
-      continue;
-    /* Merge files inside a per-directory file resolve relative to that
-       directory. */
-    if (!filter_list_parse_append_depth(list, p, opts, dir_path, 0, err, err_size)) {
-      ok = false;
-      break;
-    }
-  }
-  free(line);
   fclose(fp);
   if (!ok) {
     filter_file_rollback(list, rules_before, dir_merges_before);
     return false;
   }
-  for (int i = rules_before; i < list->count; i++) {
-    if (!set_rule_owner(list->items[i], owner_rel)) {
-      filter_set_error(err, err_size, "memory allocation failed");
-      filter_file_rollback(list, rules_before, dir_merges_before);
-      return false;
-    }
-  }
   return true;
 }
 
+bool filter_file_append(FilterRuleList* list, const char* dir_path, const char* name,
+                        const char* owner_rel, const FilterParseOptions* opts, bool* exists,
+                        char* err, size_t err_size) {
+  FilterDirMerge spec = {.name = (char*)name};
+  return filter_dir_merge_append(list, dir_path, &spec, owner_rel, opts, exists, err, err_size);
+}
+
 FilterRuleList* filter_file_read_named(const char* dir_path, const char* name,
                                        const char* owner_rel, const FilterParseOptions* opts,
                                        bool* exists, char* err, size_t err_size) {
@@ -855,6 +1028,10 @@ static FilterAction rule_matches(const FilterRule* rule, const char* rel_path, c
   }
   if (rel2[0] == '\0')
     return FILTER_ACTION_NONE;
+  /* A no-inherit rule ('n' on its dir-merge) applies only to direct children of
+   * its owner directory, never to deeper entries. */
+  if (rule->no_inherit && strchr(rel2, '/') != NULL)
+    return FILTER_ACTION_NONE;
   bool matched;
   if (rule->dir_only && !is_dir)
     matched = false;
@@ -884,3 +1061,41 @@ FilterAction filter_rules_apply_side(const FilterRuleList* list, const char* rel
   }
   return FILTER_ACTION_NONE;
 }
+
+FilterAction filter_dir_rules_apply_side(const FilterRuleList* dir_rules, const char* rel_path,
+                                         const char* leaf, bool is_dir) {
+  if (!dir_rules || !rel_path)
+    return FILTER_ACTION_NONE;
+  size_t len = strlen(rel_path);
+  if (len == 0)
+    return FILTER_ACTION_NONE;
+  /* The containing directory of rel_path is the prefix before its final '/'. */
+  size_t owner_len = 0;
+  for (size_t i = 0; i < len; i++) {
+    if (rel_path[i] == '/')
+      owner_len = i;
+  }
+  for (;;) {
+    for (int i = 0; i < dir_rules->count; i++) {
+      const FilterRule* rule = dir_rules->items[i];
+      size_t rule_owner_len = rule && rule->owner ? strlen(rule->owner) : 0;
+      if (rule_owner_len != owner_len)
+        continue;
+      if (owner_len != 0 && memcmp(rule->owner, rel_path, owner_len) != 0)
+        continue;
+      FilterAction action = rule_matches(rule, rel_path, leaf, is_dir, FILTER_SIDE_RECEIVER);
+      if (action != FILTER_ACTION_NONE)
+        return action;
+    }
+    if (owner_len == 0)
+      break;
+    /* Move to the parent directory: the last '/' before owner_len. */
+    size_t parent = 0;
+    for (size_t j = 0; j < owner_len; j++) {
+      if (rel_path[j] == '/')
+        parent = j;
+    }
+    owner_len = parent;
+  }
+  return FILTER_ACTION_NONE;
+}

src/shared/filter.h

@@ -25,11 +25,12 @@
  * Modifiers: '/' absolute anchor, '!' negate match, 'C' inject CVS defaults,
  * 's' sender side, 'r' receiver side, 'p' perishable.  The rsync 'x'
  * (xattr-name) modifier is not implemented and is rejected explicitly
- * everywhere.  The merge-file modifiers 'e' (exclude the merge file itself),
+ * everywhere.  The merge-only modifiers are accepted only on merge/dir-merge
- * 'n' (do not inherit the merge file), 'w' (word-split the merge file) and '-'
+ * rules (rejected on every other rule, matching rsync): 'e' excludes the merge
- * (do not transfer the merge file) are accepted and consumed only on merge/
+ * file itself, 'n' makes the merged rules non-inheriting (they apply only to
- * dir-merge rules (rejected on every other rule, matching rsync); their
+ * the directory that holds the merge file), 'w' word-splits the merge file on
- * semantics are not implemented and they are otherwise ignored.
+ * whitespace instead of lines, and '-' reads the merge file as a list of bare
+ * exclude patterns with no rule prefixes.
  * A trailing '/' makes a pattern match directories only.  A leading '/' anchors
  * the pattern to its owner directory.
  */
@@ -55,18 +56,32 @@ typedef struct {
   bool dir_only;       /* pattern had a trailing '/': matches directories only */
   bool negate;         /* '!' modifier: match succeeds when the pattern does not */
   bool perishable;     /* 'p' modifier (ignored in deleted directories) */
+  bool no_inherit;     /* 'n' on the owning dir-merge: applies only in `owner` */
   char* owner;         /* owning directory rel path ("" == transfer root) */
   char* pattern;       /* cleaned glob pattern (no leading '/', no trailing '/') */
 } FilterRule;
 
+/* One per-directory merge-file registration ("dir-merge NAME"/": NAME", "merge
+ * NAME"/". NAME" and -F's .rsync-filter) together with the merge-only modifiers
+ * parsed from the rule.  The scanner reads `name` in every directory it
+ * traverses and applies `no_prefixes`/`include`/`word_split`/`no_inherit`/
+ * `exclude_self` while merging the file's rules. */
+typedef struct {
+  char* name;
+  bool no_prefixes;  /* '-' : file holds only bare exclude patterns */
+  bool include;      /* '+' : file holds only bare include patterns */
+  bool word_split;   /* 'w' : split the file on whitespace, not lines */
+  bool no_inherit;   /* 'n' : the merged rules do not inherit below their dir */
+  bool exclude_self; /* 'e' : exclude the merge file itself from the transfer */
+} FilterDirMerge;
+
 typedef struct FilterRuleList {
   FilterRule** items; /* owned array of rule pointers */
   int count;
   int capacity;
-  /* Per-directory merge-file basenames registered by "dir-merge NAME"/": NAME"
+  /* Per-directory merge-file registrations.  Owned; the scanner reads each
-   * or by -F (.rsync-filter).  Owned strings; the scanner reads each name in
+   * name in every directory it traverses. */
-   * every directory it traverses. */
+  FilterDirMerge* dir_merges;
-  char** dir_merge_names;
   int dir_merge_count;
   int dir_merge_capacity;
 } FilterRuleList;
@@ -83,13 +98,23 @@ typedef struct {
 FilterRule* filter_rule_parse(const char* line, const FilterParseOptions* opts, char* err,
                               size_t err_size);
 void filter_rule_free(FilterRule* rule);
+/* Deep-copy a rule (owned pattern/owner).  Returns NULL on allocation failure. */
+FilterRule* filter_rule_clone(const FilterRule* rule);
 
 FilterRuleList* filter_rule_list_create(void);
 /* Append a fully-parsed rule (takes ownership). Returns false on OOM. */
 bool filter_rule_list_add(FilterRuleList* list, FilterRule* rule);
-/* Register a per-directory merge-file basename (idempotent). Returns false on
+/* Register a per-directory merge-file basename (idempotent, no modifiers).
- * OOM.  Used by the scanner to read custom "dir-merge" files. */
+ * Returns false on OOM.  Used by the scanner to read custom "dir-merge" files. */
 bool filter_rule_list_add_dir_merge(FilterRuleList* list, const char* name);
+/* Register a per-directory merge file with its merge-only modifiers.  On a
+ * duplicate name the existing registration is kept (rsync's first wins) and true
+ * is returned.  When `exclude_self` is set an implicit exclude rule for the
+ * merge file's basename is appended to the list at this position, matching
+ * rsync's `e` modifier.  Returns false on OOM. */
+bool filter_rule_list_add_dir_merge_ex(FilterRuleList* list, const char* name, bool no_prefixes,
+                                       bool include, bool word_split, bool no_inherit,
+                                       bool exclude_self);
 /* Parse `line` and append it.  Handles "clear"/"!" (resets the list), "merge
  * FILE"/". FILE" (splices the file's rules) and "dir-merge NAME"/": NAME"
  * (registers a per-directory filename).  Returns false and fills `err` on bad
@@ -122,6 +147,15 @@ bool filter_file_append(FilterRuleList* list, const char* dir_path, const char*
                         const char* owner_rel, const FilterParseOptions* opts, bool* exists,
                         char* err, size_t err_size);
 
+/* Append a per-directory merge file honoring its merge-only modifiers: `-`
+ * reads every (word-split, when `w`) token as a bare exclude, `+` as a bare
+ * include, and `n` marks each read rule non-inheriting.  A plain name behaves
+ * like filter_file_append.  A missing file yields *exists=false with no error;
+ * returns false only on a parse/allocation failure (message in `err`). */
+bool filter_dir_merge_append(FilterRuleList* list, const char* dir_path, const FilterDirMerge* spec,
+                             const char* owner_rel, const FilterParseOptions* opts, bool* exists,
+                             char* err, size_t err_size);
+
 /* filter_file_read_named with the default ".rsync-filter" name. */
 FilterRuleList* filter_file_read(const char* dir_path, const char* owner_rel, bool* exists,
                                  char* err, size_t err_size);
@@ -135,4 +169,15 @@ FilterRuleList* filter_file_read(const char* dir_path, const char* owner_rel, bo
 FilterAction filter_rules_apply_side(const FilterRuleList* list, const char* rel_path,
                                      const char* leaf, bool is_dir, unsigned side);
 
+/* Evaluate a received per-directory rule set for the receiver side, using
+ * rsync's per-directory-before-ancestors order: the entry's containing
+ * directory's rules are tried first, then each ancestor's, then the receive
+ * root's.  `dir_rules` is a flat list whose rules carry `owner`; a rule applies
+ * only when `owner` is exactly the directory being examined (a no-inherit rule
+ * therefore applies only to that directory's direct children).  Returns the
+ * first matching rule's receiver verdict (PROTECT/RISK) or FILTER_ACTION_NONE.
+ * The caller evaluates the command-line base rules after this chain. */
+FilterAction filter_dir_rules_apply_side(const FilterRuleList* dir_rules, const char* rel_path,
+                                         const char* leaf, bool is_dir);
+
 #endif

src/shared/multiprocessing.c

@@ -34,6 +34,7 @@ PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* que
   context->synced_dirs = NULL;
   context->plan_dirs = NULL;
   context->missing_args = NULL;
+  context->per_dir_rules = NULL;
   context->scan_had_io_error = false;
   context->remove_source_files = NULL;
   context->early_delete = false;
@@ -210,6 +211,8 @@ void pipeline_context_sender_destroy(PipelineContextSender* context) {
     array_list_delete(context->plan_dirs);
   if (context->missing_args)
     array_list_delete(context->missing_args);
+  if (context->per_dir_rules)
+    filter_rule_list_free(context->per_dir_rules);
   if (context->remove_source_files)
     array_list_delete(context->remove_source_files);
   if (context->dir_entries)

src/shared/multiprocessing.h

@@ -67,6 +67,12 @@ typedef struct {
      them in the manifest frame's third section and the receiver deletes each as
      an explicit request. */
   ArrayList* missing_args;
+  /* Per-directory filter rules the source scan compiled (protocol 2.30.0),
+     sent with the delete manifest/plan config so the receiver can re-derive the
+     per-directory protect/risk set.  NULL when --delete is off.  Populated by
+     the scanner (parallel workers append under mutex_scanner) or the early
+     pre-scan. */
+  FilterRuleList* per_dir_rules;
   /* A source I/O error (unreadable directory) was recorded during the scan.
      Set by the pre-scan (before the threads start) or by the scanner thread
      under mutex_scanner; the caller turns it into a non-zero exit when

tests/integration/test_differential_parity.py

@@ -128,6 +128,39 @@ def seed_filter_protect(_src, rroot, froot):
         _mk(os.path.join(root, "sub", "other2.txt"), b"nested dest-only other\n", _OLD_MTIME)
 
 
+def seed_perdir_protect(_src, rroot, froot):
+    """Per-directory `.rsync-filter` carrying `P` rules on the source and both
+    destinations, plus destination-only extras.  The `.log` extras must survive
+    --delete under every timing while the other extras go; the source's
+    `.rsync-filter` (which FastSync carries to the receiver) and the seeded
+    destination one (which rsync's receiver reads) are byte-identical."""
+    for root in (_src, rroot, froot):
+        _mk(os.path.join(root, ".rsync-filter"), b"P extra.log\nP nested.log\n")
+    for root in (rroot, froot):
+        _mk(os.path.join(root, "extra.log"), b"dest-only protected\n", _OLD_MTIME)
+        _mk(os.path.join(root, "other.txt"), b"dest-only deleted\n", _OLD_MTIME)
+        _mk(os.path.join(root, "sub", "nested.log"), b"nested protected\n", _OLD_MTIME)
+        _mk(os.path.join(root, "sub", "other2.txt"), b"nested deleted\n", _OLD_MTIME)
+
+
+def seed_perdir_exclude(_src, rroot, froot):
+    """Per-directory unqualified exclude (`-`): dual-sided, so it protects the
+    matching destination-only extra (and is opted back in by
+    --delete-excluded)."""
+    for root in (_src, rroot, froot):
+        _mk(os.path.join(root, ".rsync-filter"), b"- extra.log\n")
+    for root in (rroot, froot):
+        _mk(os.path.join(root, "extra.log"), b"dest-only excluded\n", _OLD_MTIME)
+        _mk(os.path.join(root, "other.txt"), b"dest-only deleted\n", _OLD_MTIME)
+
+
+def _seed_rules(content):
+    def seed(_src, _rroot, _froot):
+        _mk(os.path.join(_src, ".rules"), content)
+
+    return seed
+
+
 def seed_max_delete(_src, rroot, froot):
     for root in (rroot, froot):
         _mk(os.path.join(root, "extra1.txt"), b"e1\n", _OLD_MTIME)
@@ -272,6 +305,50 @@ _CASES = [
            ["-a", "--delete-after", "--filter=P *.log"],
            seed=seed_filter_protect, server_args=DELETE, ci=True,
            ref="--filter P/--protect under the whole-tree --delete-after commit"),
+    # Per-directory merge rules (#315): the receiver must re-derive the
+    # protect/risk verdict from the carried per-directory rules, so a
+    # destination-only entry matching ONLY a per-directory rule is shielded.
+    H.Case("filter_perdir_protect", "filters",
+           ["-a", "-F", "--delete"],
+           seed=seed_perdir_protect, server_args=DELETE, ci=True,
+           ref="-F per-directory P rule under the default --delete timing"),
+    H.Case("filter_perdir_protect_during", "filters",
+           ["-a", "-F", "--delete-during"],
+           seed=seed_perdir_protect, server_args=DELETE, ci=True,
+           ref="-F per-directory P rule under --delete-during"),
+    H.Case("filter_perdir_protect_delay", "filters",
+           ["-a", "-F", "--delete-delay"],
+           seed=seed_perdir_protect, server_args=DELETE, ci=True,
+           ref="-F per-directory P rule under --delete-delay"),
+    H.Case("filter_perdir_protect_before", "filters",
+           ["-a", "-F", "--delete-before"],
+           seed=seed_perdir_protect, server_args=DELETE, ci=True,
+           ref="-F per-directory P rule under the whole-tree --delete-before commit"),
+    H.Case("filter_perdir_protect_after", "filters",
+           ["-a", "-F", "--delete-after"],
+           seed=seed_perdir_protect, server_args=DELETE, ci=True,
+           ref="-F per-directory P rule under the whole-tree --delete-after commit"),
+    H.Case("filter_perdir_exclude_protect", "filters",
+           ["-a", "-F", "--delete"],
+           seed=seed_perdir_exclude, server_args=DELETE, ci=True,
+           ref="-F per-directory exclude protects its destination mirror"),
+    H.Case("filter_perdir_exclude_deleted", "filters",
+           ["-a", "-F", "--delete", "--delete-excluded"],
+           seed=seed_perdir_exclude, server_args=DELETE, ci=True,
+           ref="-F per-directory exclude under --delete-excluded is at risk"),
+    # Merge-file modifiers (#315): e/n/w/- semantics match rsync 3.4.1.
+    H.Case("dir_merge_e", "filters", ["-a", "--filter=:e .rules"],
+           seed=_seed_rules(b"- *.log\n"), ci=True,
+           ref="dir-merge,e excludes the merge file itself"),
+    H.Case("dir_merge_n", "filters", ["-a", "--filter=:n .rules"],
+           seed=_seed_rules(b"- *.log\n"), ci=True,
+           ref="dir-merge,n does not inherit into subdirectories"),
+    H.Case("dir_merge_dash", "filters", ["-a", "--filter=:- .rules"],
+           seed=_seed_rules(b"*.log\n*.bin\n"), ci=True,
+           ref="dir-merge,- reads the file as bare exclude patterns"),
+    H.Case("dir_merge_w", "filters", ["-a", "--filter=:-w .rules"],
+           seed=_seed_rules(b"*.log *.bin\n"), ci=True,
+           ref="dir-merge,w word-splits bare patterns on whitespace"),
 
     # --- relative / dirs --------------------------------------------------
     H.Case("relative_general", "basic", ["-a", "-R"], layout=H.MIRROR_ABS,

tests/integration/test_option_parity.py

@@ -536,3 +536,78 @@ class TestFilterProtect:
         assert "extra.log" not in result.stdout, result.stdout
         assert os.path.exists(os.path.join(received, "extra.log"))
         assert os.path.exists(os.path.join(received, "other.txt"))
+
+    @pytest.mark.ci
+    def test_perdir_protect_dest_only_matches_rsync(self):
+        """#315: a `P` rule inside a per-directory `.rsync-filter` is carried to
+        the receiver, so a destination-only extra matching ONLY that rule is
+        shielded under --delete.  Both roots carry the same filter file (rsync's
+        receiver reads the destination one; FastSync carries the source's)."""
+        source = os.path.join(TEST_DATA_DIR, "fpdp_src")
+        dest = os.path.join(TEST_DATA_DIR, "fpdp_dst")
+        rdst = os.path.join(TEST_DATA_DIR, "fpdp_rdst")
+        clean_dir(source)
+        _write(os.path.join(source, "keep.txt"), b"keep\n")
+        _write(os.path.join(source, ".rsync-filter"), b"P extra.log\n")
+        clean_dir(rdst)
+        _write(os.path.join(rdst, ".rsync-filter"), b"P extra.log\n")
+        _write(os.path.join(rdst, "extra.log"), b"extra\n")
+        _write(os.path.join(rdst, "other.txt"), b"other\n")
+
+        rsync_result = _rsync(["-aF", "--delete", source + "/", rdst + "/"])
+        assert rsync_result.returncode == 0, rsync_result.stderr
+        assert os.path.exists(os.path.join(rdst, "extra.log")), "rsync did not protect extra.log"
+        assert not os.path.exists(os.path.join(rdst, "other.txt"))
+
+        clean_dir(dest)
+        received = get_dest_received_dir(dest, source)
+        os.makedirs(received, exist_ok=True)
+        _write(os.path.join(received, ".rsync-filter"), b"P extra.log\n")
+        _write(os.path.join(received, "extra.log"), b"extra\n")
+        _write(os.path.join(received, "other.txt"), b"other\n")
+        with ServerManager() as server:
+            server.start(extra_args=["--allow-delete"])
+            result, _ = run_client(source, dest, flags=["-aF", "--delete"], port=server.port)
+        assert result.returncode == 0, (result.stderr or result.stdout)[:300]
+        assert os.path.exists(os.path.join(received, "extra.log")), (
+            "FastSync must protect a destination-only per-directory P match like rsync")
+        assert not os.path.exists(os.path.join(received, "other.txt"))
+
+    @requires_rsync
+    @pytest.mark.ci
+    def test_perdir_protect_dry_run_enumeration(self, shared_server):
+        """#315: the -n/--dry-run would-delete enumeration also honors the
+        carried per-directory rules, matching rsync's `*deleting` set: a
+        destination-only entry matching only a `.rsync-filter` P rule is not
+        reported (nor removed)."""
+        source = os.path.join(TEST_DATA_DIR, "fpdp_nd_src")
+        dest = os.path.join(TEST_DATA_DIR, "fpdp_nd_dst")
+        rdst = os.path.join(TEST_DATA_DIR, "fpdp_nd_rdst")
+        clean_dir(source)
+        _write(os.path.join(source, "keep.txt"), b"keep\n")
+        _write(os.path.join(source, ".rsync-filter"), b"P extra.log\n")
+        received = get_dest_received_dir(dest, source)
+        clean_dir(rdst)
+        clean_dir(received)
+        for root in (rdst, received):
+            _write(os.path.join(root, "keep.txt"), b"keep\n")
+            _write(os.path.join(root, ".rsync-filter"), b"P extra.log\n")
+            _write(os.path.join(root, "extra.log"), b"extra\n")
+            _write(os.path.join(root, "other.txt"), b"other\n")
+
+        rsync_result = _rsync(["-an", "-i", "-F", "--delete", source + "/", rdst + "/"])
+        assert rsync_result.returncode == 0, rsync_result.stderr
+        rsync_del = sorted(l for l in rsync_result.stdout.splitlines()
+                           if l.startswith("*deleting"))
+        assert rsync_del == ["*deleting   other.txt"], f"unexpected rsync set: {rsync_del}"
+
+        with ServerManager() as server:
+            server.start(extra_args=["--allow-delete"])
+            result, _ = run_client(source, dest, flags=["-aF", "-n", "-i", "--delete"],
+                                   port=server.port)
+        assert result.returncode == 0, (result.stderr or result.stdout)[:300]
+        fs_del = sorted(l for l in (result.stdout or "").splitlines()
+                        if l.startswith("*deleting"))
+        assert fs_del == rsync_del, f"rsync={rsync_del}\nfastsync={fs_del}"
+        assert os.path.exists(os.path.join(received, "extra.log"))
+        assert os.path.exists(os.path.join(received, "other.txt"))

tests/test_delete_plan.c

@@ -225,6 +225,7 @@ static void send_config_only_frame(int fd, const char* missing_path) {
   EXPECT_TRUE(send_int(fd, 0)); /* size-skipped */
   EXPECT_TRUE(send_int(fd, 1)); /* missing args */
   EXPECT_TRUE(send_wire_str(fd, missing_path));
+  EXPECT_TRUE(send_int(fd, 0)); /* per-directory filter-rule block is empty */
   EXPECT_TRUE(send_int(fd, 0)); /* apply = false */
   EXPECT_TRUE(send_wire_str(fd, "."));
   EXPECT_TRUE(send_int(fd, 0));
@@ -265,10 +266,111 @@ static void test_config_only_frame_applies_missing_args(void) {
   config_delete(config);
 }
 
+/* The per-directory filter-rule block (protocol 2.30.0) must be bounded on
+ * receive: every count, the action/sides domain, the owner-directory syntax and
+ * the pattern length are validated so a hostile peer can neither overread nor
+ * allocate unboundedly.  It also round-trips a valid group faithfully. */
+static void test_filter_dir_rules_receive_bounds(void) {
+  int p[2];
+  FilterRuleList* out = NULL;
+
+  /* Group count beyond the cap is rejected. */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], MAX_FILTER_RULES + 1));
+  EXPECT_FALSE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NULL(out);
+  close(p[0]);
+  close(p[1]);
+
+  /* A negative group count is rejected. */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], -1));
+  EXPECT_FALSE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NULL(out);
+  close(p[0]);
+  close(p[1]);
+
+  /* An empty block is valid and yields NULL. */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], 0));
+  EXPECT_TRUE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NULL(out);
+  close(p[0]);
+  close(p[1]);
+
+  /* An unknown action is a protocol error. */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], 1));
+  EXPECT_TRUE(send_wire_str(p[1], ""));
+  EXPECT_TRUE(send_int(p[1], 1));
+  EXPECT_TRUE(send_int(p[1], 999));
+  EXPECT_FALSE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NULL(out);
+  close(p[0]);
+  close(p[1]);
+
+  /* An absolute owner directory is rejected (confinement). */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], 1));
+  EXPECT_TRUE(send_wire_str(p[1], "/etc"));
+  EXPECT_TRUE(send_int(p[1], 0));
+  EXPECT_FALSE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NULL(out);
+  close(p[0]);
+  close(p[1]);
+
+  /* An over-long pattern is rejected before allocation. */
+  {
+    char* big = malloc(MAX_PROTECT_PATTERN_LEN + 2);
+    EXPECT_NOT_NULL(big);
+    memset(big, 'a', MAX_PROTECT_PATTERN_LEN + 1);
+    big[MAX_PROTECT_PATTERN_LEN + 1] = '\0';
+    EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+    EXPECT_TRUE(send_int(p[1], 1));
+    EXPECT_TRUE(send_wire_str(p[1], ""));
+    EXPECT_TRUE(send_int(p[1], 1));
+    EXPECT_TRUE(send_int(p[1], (int)FILTER_ACTION_EXCLUDE));
+    EXPECT_TRUE(send_int(p[1], (int)(FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER)));
+    EXPECT_TRUE(send_int(p[1], 0));
+    EXPECT_TRUE(send_int(p[1], 0));
+    EXPECT_TRUE(send_int(p[1], 0));
+    EXPECT_TRUE(send_int(p[1], 0));
+    EXPECT_TRUE(send_wire_str(p[1], big));
+    EXPECT_FALSE(delete_filter_dir_rules_receive(p[0], &out));
+    EXPECT_NULL(out);
+    close(p[0]);
+    close(p[1]);
+    free(big);
+  }
+
+  /* A valid group round-trips its owner, no-inherit flag and pattern. */
+  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
+  EXPECT_TRUE(send_int(p[1], 1));
+  EXPECT_TRUE(send_wire_str(p[1], "sub"));
+  EXPECT_TRUE(send_int(p[1], 1));
+  EXPECT_TRUE(send_int(p[1], (int)FILTER_ACTION_EXCLUDE));
+  EXPECT_TRUE(send_int(p[1], (int)(FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER)));
+  EXPECT_TRUE(send_int(p[1], 0));
+  EXPECT_TRUE(send_int(p[1], 0));
+  EXPECT_TRUE(send_int(p[1], 0));
+  EXPECT_TRUE(send_int(p[1], 1)); /* no_inherit */
+  EXPECT_TRUE(send_wire_str(p[1], "*.log"));
+  EXPECT_TRUE(delete_filter_dir_rules_receive(p[0], &out));
+  EXPECT_NOT_NULL(out);
+  EXPECT_EQ_INT(out->count, 1);
+  EXPECT_EQ_STR(out->items[0]->owner, "sub");
+  EXPECT_EQ_STR(out->items[0]->pattern, "*.log");
+  EXPECT_TRUE(out->items[0]->no_inherit);
+  filter_rule_list_free(out);
+  close(p[0]);
+  close(p[1]);
+}
+
 void test_delete_plan(void) {
   test_delete_delay_refilled_dir_removed_recursively();
   test_delete_delay_removed_file_counted();
   test_delete_delay_max_delete_bounds_actual();
   test_delete_delay_actual_removal_charges_budget();
   test_config_only_frame_applies_missing_args();
+  test_filter_dir_rules_receive_bounds();
 }

tests/test_filter.c

@@ -1,6 +1,7 @@
 #include "test_filter.h"
 #include "filter.h"
 #include "test_utils.h"
+#include "utils.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -64,44 +65,47 @@ static void test_filter_list_rejects_unsupported_modifiers() {
 }
 
 /* rsync accepts the merge-file modifiers e/n/w/- on merge and dir-merge rules.
- * They must be consumed so they never leak into the merge filename. */
+ * They must be consumed so they never leak into the merge filename, and their
+ * semantics (exclude-self, no-inherit, word-split, no-prefixes) must be
+ * applied while the file is read. */
 static void test_filter_list_accepts_merge_modifiers() {
   char tmpl[] = "/tmp/fastsync_filter_mmod_XXXXXX";
   EXPECT_TRUE(mkdtemp(tmpl) != NULL);
-  char path[512];
+  char prefixed[512];
-  snprintf(path, sizeof(path), "%s/rules", tmpl);
+  char bare[512];
-  FILE* fp = fopen(path, "w");
+  char words[512];
+  snprintf(prefixed, sizeof(prefixed), "%s/prefixed", tmpl);
+  snprintf(bare, sizeof(bare), "%s/bare", tmpl);
+  snprintf(words, sizeof(words), "%s/words", tmpl);
+  FILE* fp = fopen(prefixed, "w");
   EXPECT_NOT_NULL(fp);
   fputs("- *.tmp\n", fp);
   fclose(fp);
+  fp = fopen(bare, "w");
+  EXPECT_NOT_NULL(fp);
+  fputs("*.log\n*.tmp\n", fp);
+  fclose(fp);
+  fp = fopen(words, "w");
+  EXPECT_NOT_NULL(fp);
+  fputs("*.log *.tmp\n", fp);
+  fclose(fp);
 
-  /* merge with e/n/w/- consumes the modifiers and reads the right file. */
+  /* dir-merge with e/n/w/- registers the basename without the modifiers and
-  static const char* const fmts[] = {
+   * records the modifier flags; 'e' appends an exclude-self rule. */
-      "merge,e %s", "merge,n %s", "merge,w %s", "merge,- %s", ".e %s", ".- %s",
-  };
-  for (size_t i = 0; i < sizeof(fmts) / sizeof(fmts[0]); i++) {
-    FilterRuleList* list = filter_rule_list_create();
-    EXPECT_NOT_NULL(list);
-    char rule[600];
-    char err[256] = "";
-    snprintf(rule, sizeof(rule), fmts[i], path);
-    bool ok = filter_rule_list_parse_append(list, rule, NULL, NULL, err, sizeof(err));
-    if (!ok)
-      printf("    merge rule '%s' errored: %s\n", rule, err);
-    EXPECT_TRUE(ok);
-    EXPECT_EQ_INT(list->count, 1);
-    EXPECT_EQ_STR(list->items[0]->pattern, "*.tmp");
-    filter_rule_list_free(list);
-  }
-
-  /* dir-merge with e/n/w/- registers the basename without the modifiers. */
   static const struct {
     const char* rule;
     const char* want;
+    bool no_prefixes;
+    bool word_split;
+    bool no_inherit;
+    bool exclude_self;
   } drules[] = {
-      {"dir-merge,e .rules", ".rules"}, {"dir-merge,n .rules", ".rules"},
+      {"dir-merge,e .rules", ".rules", false, false, false, true},
-      {"dir-merge,w .rules", ".rules"}, {"dir-merge,- .rules", ".rules"},
+      {"dir-merge,n .rules", ".rules", false, false, true, false},
-      {":e .rules", ".rules"},          {":- .rules", ".rules"},
+      {"dir-merge,w .rules", ".rules", false, true, false, false},
+      {"dir-merge,- .rules", ".rules", true, false, false, false},
+      {":e .rules", ".rules", false, false, false, true},
+      {":- .rules", ".rules", true, false, false, false},
   };
   for (size_t i = 0; i < sizeof(drules) / sizeof(drules[0]); i++) {
     FilterRuleList* list = filter_rule_list_create();
@@ -112,11 +116,78 @@ static void test_filter_list_accepts_merge_modifiers() {
       printf("    dir-merge rule '%s' errored: %s\n", drules[i].rule, err);
     EXPECT_TRUE(ok);
     EXPECT_EQ_INT(list->dir_merge_count, 1);
-    EXPECT_EQ_STR(list->dir_merge_names[0], drules[i].want);
+    EXPECT_EQ_STR(list->dir_merges[0].name, drules[i].want);
+    EXPECT_EQ_INT(list->dir_merges[0].no_prefixes, drules[i].no_prefixes);
+    EXPECT_EQ_INT(list->dir_merges[0].word_split, drules[i].word_split);
+    EXPECT_EQ_INT(list->dir_merges[0].no_inherit, drules[i].no_inherit);
+    EXPECT_EQ_INT(list->dir_merges[0].exclude_self, drules[i].exclude_self);
+    if (drules[i].exclude_self) {
+      EXPECT_EQ_INT(list->count, 1);
+      EXPECT_EQ_STR(list->items[0]->pattern, ".rules");
+      EXPECT_EQ_INT(list->items[0]->action, FILTER_ACTION_EXCLUDE);
+    } else {
+      EXPECT_EQ_INT(list->count, 0);
+    }
     filter_rule_list_free(list);
   }
 
-  unlink(path);
+  /* merge,n reads the file normally; no-inherit is meaningless for a single
+   * merge so the rule is not marked. */
+  {
+    FilterRuleList* list = filter_rule_list_create();
+    char err[256] = "";
+    char rule[600];
+    snprintf(rule, sizeof(rule), "merge,n %s", prefixed);
+    EXPECT_TRUE(filter_rule_list_parse_append(list, rule, NULL, NULL, err, sizeof(err)));
+    EXPECT_EQ_INT(list->count, 1);
+    EXPECT_EQ_STR(list->items[0]->pattern, "*.tmp");
+    EXPECT_FALSE(list->items[0]->no_inherit);
+    filter_rule_list_free(list);
+  }
+
+  /* merge,e adds an implicit exclude for the merge file's basename. */
+  {
+    FilterRuleList* list = filter_rule_list_create();
+    char err[256] = "";
+    char rule[600];
+    snprintf(rule, sizeof(rule), "merge,e %s", prefixed);
+    EXPECT_TRUE(filter_rule_list_parse_append(list, rule, NULL, NULL, err, sizeof(err)));
+    EXPECT_EQ_INT(list->count, 2);
+    EXPECT_EQ_STR(list->items[0]->pattern, "prefixed");
+    EXPECT_EQ_INT(list->items[0]->action, FILTER_ACTION_EXCLUDE);
+    EXPECT_EQ_STR(list->items[1]->pattern, "*.tmp");
+    filter_rule_list_free(list);
+  }
+
+  /* merge,- reads the file as bare exclude patterns with no prefix parsing. */
+  {
+    FilterRuleList* list = filter_rule_list_create();
+    char err[256] = "";
+    char rule[600];
+    snprintf(rule, sizeof(rule), "merge,- %s", bare);
+    EXPECT_TRUE(filter_rule_list_parse_append(list, rule, NULL, NULL, err, sizeof(err)));
+    EXPECT_EQ_INT(list->count, 2);
+    EXPECT_EQ_STR(list->items[0]->pattern, "*.log");
+    EXPECT_EQ_STR(list->items[1]->pattern, "*.tmp");
+    filter_rule_list_free(list);
+  }
+
+  /* merge,-w word-splits bare patterns on whitespace. */
+  {
+    FilterRuleList* list = filter_rule_list_create();
+    char err[256] = "";
+    char rule[600];
+    snprintf(rule, sizeof(rule), "merge,w- %s", words);
+    EXPECT_TRUE(filter_rule_list_parse_append(list, rule, NULL, NULL, err, sizeof(err)));
+    EXPECT_EQ_INT(list->count, 2);
+    EXPECT_EQ_STR(list->items[0]->pattern, "*.log");
+    EXPECT_EQ_STR(list->items[1]->pattern, "*.tmp");
+    filter_rule_list_free(list);
+  }
+
+  unlink(prefixed);
+  unlink(bare);
+  unlink(words);
   rmdir(tmpl);
 }
 
@@ -283,6 +354,76 @@ static void test_filter_rules_apply_supported_modifiers() {
   }
 }
 
+static FilterRule* chain_rule(const char* owner, const char* pattern, FilterAction action,
+                              bool no_inherit) {
+  FilterRule* rule = calloc(1, sizeof(FilterRule));
+  if (!rule)
+    return NULL;
+  rule->action = action;
+  rule->sides = FILTER_SIDE_SENDER | FILTER_SIDE_RECEIVER;
+  rule->owner = str_dup(owner);
+  rule->pattern = str_dup(pattern);
+  rule->no_inherit = no_inherit;
+  if (!rule->owner || !rule->pattern) {
+    filter_rule_free(rule);
+    return NULL;
+  }
+  return rule;
+}
+
+/* The receiver's per-directory chain: a containing directory's rules win over
+ * an ancestor's (deepest-first), root rules are inherited, and a no-inherit
+ * rule applies only to its own directory's direct children. */
+static void test_filter_dir_rules_chain(void) {
+  FilterRuleList* list = filter_rule_list_create();
+  EXPECT_NOT_NULL(list);
+  FilterRule* root_log = chain_rule("", "*.log", FILTER_ACTION_EXCLUDE, false);
+  FilterRule* sub_keep = chain_rule("sub", "keep.log", FILTER_ACTION_INCLUDE, false);
+  FilterRule* sub_tmp = chain_rule("sub", "*.tmp", FILTER_ACTION_EXCLUDE, true);
+  EXPECT_NOT_NULL(root_log);
+  EXPECT_NOT_NULL(sub_keep);
+  EXPECT_NOT_NULL(sub_tmp);
+  EXPECT_TRUE(filter_rule_list_add(list, root_log));
+  EXPECT_TRUE(filter_rule_list_add(list, sub_keep));
+  EXPECT_TRUE(filter_rule_list_add(list, sub_tmp));
+
+  /* Root rule inherited by every directory (leaf match). */
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "a.log", "a.log", false), FILTER_ACTION_PROTECT);
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "sub/a.log", "a.log", false),
+                FILTER_ACTION_PROTECT);
+  /* The deeper include overrides the inherited root exclude. */
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "sub/keep.log", "keep.log", false),
+                FILTER_ACTION_RISK);
+  /* No-inherit applies directly in its owner... */
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "sub/x.tmp", "x.tmp", false),
+                FILTER_ACTION_PROTECT);
+  /* ...but not below it. */
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "sub/deep/x.tmp", "x.tmp", false),
+                FILTER_ACTION_NONE);
+  /* No matching rule. */
+  EXPECT_EQ_INT(filter_dir_rules_apply_side(list, "sub/deep/plain.txt", "plain.txt", false),
+                FILTER_ACTION_NONE);
+  filter_rule_list_free(list);
+}
+
+static void test_filter_rule_clone_copies_every_field(void) {
+  char err[128] = "";
+  FilterRule* original = filter_rule_parse("-!p /a/*.o", NULL, err, sizeof(err));
+  EXPECT_NOT_NULL(original);
+  FilterRule* copy = filter_rule_clone(original);
+  EXPECT_NOT_NULL(copy);
+  EXPECT_TRUE(copy != original);
+  EXPECT_EQ_INT(copy->action, original->action);
+  EXPECT_EQ_INT(copy->sides, original->sides);
+  EXPECT_EQ_INT(copy->anchored, original->anchored);
+  EXPECT_EQ_INT(copy->dir_only, original->dir_only);
+  EXPECT_EQ_INT(copy->negate, original->negate);
+  EXPECT_EQ_INT(copy->perishable, original->perishable);
+  EXPECT_EQ_STR(copy->pattern, original->pattern);
+  filter_rule_free(original);
+  filter_rule_free(copy);
+}
+
 void test_filter() {
   test_filter_list_rejects_xattr_modifier();
   test_filter_list_rejects_unsupported_modifiers();
@@ -291,4 +432,6 @@ void test_filter() {
   test_filter_list_merge_file_still_supported();
   test_filter_rule_parse_rejects_unsupported_and_keeps_supported();
   test_filter_rules_apply_supported_modifiers();
+  test_filter_dir_rules_chain();
+  test_filter_rule_clone_copies_every_field();
 }

tests/test_server.c

@@ -708,6 +708,7 @@ static void test_late_manifest_abort_frees_keepset() {
   EXPECT_TRUE(send_int(p[1], 0)); /* protected-prefix section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* missing-args section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* synchronized-directories section is empty */
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
   EXPECT_TRUE(send_status(p[1], STATUS_ABORT));
 
   DeleteManifest* pending = NULL;
@@ -733,6 +734,7 @@ static void test_late_manifest_eof_frees_keepset() {
   EXPECT_TRUE(send_int(p[1], 0)); /* protected-prefix section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* missing-args section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* synchronized-directories section is empty */
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
   shutdown(p[1], SHUT_WR);
 
   DeleteManifest* pending = NULL;
@@ -758,12 +760,14 @@ static void test_late_second_manifest_frees_both() {
   EXPECT_TRUE(send_int(p[1], 0)); /* protected-prefix section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* missing-args section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* synchronized-directories section is empty */
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
   EXPECT_TRUE(send_status(p[1], STATUS_MANIFEST));
   EXPECT_TRUE(send_int(p[1], 1));
   EXPECT_TRUE(send_str(p[1], "second.txt"));
   EXPECT_TRUE(send_int(p[1], 0)); /* protected-prefix section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* missing-args section is empty */
   EXPECT_TRUE(send_int(p[1], 0)); /* synchronized-directories section is empty */
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
 
   DeleteManifest* pending = NULL;
   EXPECT_EQ_INT(run_pending_receiver(cfg, p[0], &pending), -1);
@@ -799,6 +803,7 @@ static void test_receive_manifest_three_sections() {
   EXPECT_TRUE(send_int(p[1], 2));
   EXPECT_TRUE(send_str(p[1], "."));
   EXPECT_TRUE(send_str(p[1], "dir"));
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
 
   DeleteManifest* manifest = receive_manifest_entries(p[0]);
   EXPECT_NOT_NULL(manifest);
@@ -917,6 +922,7 @@ static void test_receiver_pending_commits_missing_args() {
   EXPECT_TRUE(send_str(p[1], "gone.txt"));
   EXPECT_TRUE(send_str(p[1], "never_here.txt"));
   EXPECT_TRUE(send_int(p[1], 0)); /* no synchronized directories */
+  EXPECT_TRUE(send_int(p[1], 0)); /* per-directory filter-rule block is empty */
   EXPECT_TRUE(send_status(p[1], STATUS_FINISHED));
 
   /* NULL pending: the single-threaded commit path deletes at FINISHED.  The
@@ -1309,6 +1315,7 @@ static void test_dry_run_delete_plan_commit_does_not_delete() {
   EXPECT_TRUE(send_int(p[1], 0)); /* size-skipped prefixes */
   EXPECT_TRUE(send_int(p[1], 1)); /* missing-args exact deletions */
   EXPECT_TRUE(send_str(p[1], "victim.txt"));
+  EXPECT_TRUE(send_int(p[1], 0));   /* per-directory filter-rule block is empty */
   EXPECT_TRUE(send_int(p[1], 1));   /* apply: a real plan */
   EXPECT_TRUE(send_str(p[1], ".")); /* receive root plan */
   EXPECT_TRUE(send_int(p[1], 0));   /* kept child directories */

tests/test_shared_utils.c

@@ -349,8 +349,9 @@ static void test_walker_protect_rules_shield_dest_only() {
   FilterRuleList* rules = filter_base_build(rule_text, 3, false, false, err, sizeof(err));
   EXPECT_NOT_NULL(rules);
   size_t deleted = 0;
+  DeleteProtectRules protect = {.base_rules = rules, .dir_rules = NULL};
   DeleteWalkResult result =
-      delete_extras_limited(root, manifest, NULL, 100000, NULL, 0, rules, &deleted, NULL);
+      delete_extras_limited(root, manifest, NULL, 100000, NULL, 0, &protect, &deleted, NULL);
   EXPECT_EQ_INT((int)result, (int)DELETE_WALK_OK);
   EXPECT_TRUE(file_exists(root, "keep.txt"));
   EXPECT_FALSE(file_exists(root, "extra.log")); /* risk wins the first match */