src/client/client_send.c

@@ -136,6 +136,7 @@ typedef struct {
   ScannerOptions options;
   FilterRuleList* base_filters; /* owned; may be NULL */
   HardLinkTable* hardlinks;     /* owned; may be NULL */
+  char* relative_prefix;        /* owned -R prefix; may be NULL */
 } PreparedScanner;
 
 /* Build the scanner options for one scan. Returns false and logs on failure. */
@@ -144,6 +145,7 @@ static bool prepare_scanner(const Config* config, int num_threads, PreparedScann
     return false;
   out->base_filters = NULL;
   out->hardlinks = NULL;
+  out->relative_prefix = NULL;
   memset(&out->options, 0, sizeof(out->options));
 
   int rule_count = config->filters ? config->filters->size : 0;
@@ -206,6 +208,19 @@ static bool prepare_scanner(const Config* config, int num_threads, PreparedScann
   options->per_dir_filters = config->per_dir_filter;
   options->dirs = config->dirs;
   options->relative = config->relative;
+  /* -R/--relative outside --files-from reconstructs every destination path from
+   * the source spec (rsync's '/./' cut point).  With --files-from the listed
+   * entry already supplies the bare relative path, so no prefix is built. */
+  if (config->relative && config->files_from_set == NULL && config->send_directory) {
+    out->relative_prefix = scanner_relative_prefix(config->send_directory);
+    if (!out->relative_prefix) {
+      log_message(LOG_LEVEL_ERROR, "memory allocation failed building --relative path prefix");
+      filter_rule_list_free(out->base_filters);
+      out->base_filters = NULL;
+      return false;
+    }
+    options->relative_prefix = out->relative_prefix;
+  }
   options->prune_empty_dirs = config->prune_empty_dirs;
   options->ignore_io_errors = config->ignore_errors;
   options->ignore_missing_args = config->ignore_missing_args || config->delete_missing_args;
@@ -239,6 +254,85 @@ static void prepared_scanner_destroy(PreparedScanner* prepared) {
   prepared->base_filters = NULL;
   hardlink_table_destroy(prepared->hardlinks);
   prepared->hardlinks = NULL;
+  free(prepared->relative_prefix);
+  prepared->relative_prefix = NULL;
+}
+
+/* -R/--relative implied directories: rsync transmits the metadata of the
+ * parent directories implied by the source path (every prefix component above
+ * the source root) so the receiver applies their attributes to the created
+ * parents.  FastSync's scan only covers the source root and below, so append
+ * one metadata-only directory entry per implied ancestor.  --no-implied-dirs
+ * suppresses this exactly like rsync.  A missing ancestor is never fatal. */
+static bool append_implied_dir_times(const Config* config, ArrayList* dir_entries) {
+  if (!dir_entries || !config->relative || config->files_from_set != NULL ||
+      config->no_implied_dirs || !config->send_directory)
+    return true;
+  char* prefix = scanner_relative_prefix(config->send_directory);
+  if (!prefix)
+    return true;
+  int ncomp = 0;
+  for (const char* s = prefix; *s;) {
+    while (*s == '/')
+      s++;
+    if (!*s)
+      break;
+    while (*s && *s != '/')
+      s++;
+    ncomp++;
+  }
+  if (ncomp <= 1) {
+    free(prefix);
+    return true;
+  }
+  char* fs = str_dup(config->send_directory);
+  if (!fs) {
+    free(prefix);
+    return true;
+  }
+  size_t flen = strlen(fs);
+  while (flen > 1 && fs[flen - 1] == '/')
+    fs[--flen] = '\0';
+  bool ok = true;
+  /* Walk the source path upwards one component at a time; the previous
+     iteration's truncation is restored so every ancestor is stat'ed in full. */
+  for (int depth = ncomp - 2; depth >= 0 && ok; depth--) {
+    char* slash = strrchr(fs, '/');
+    if (!slash || slash == fs)
+      break;
+    *slash = '\0';
+    char* p = prefix;
+    int c = 0;
+    while (c <= depth) {
+      while (*p == '/')
+        p++;
+      while (*p && *p != '/')
+        p++;
+      c++;
+    }
+    char saved = *p;
+    *p = '\0';
+    struct stat st;
+    if (stat(fs, &st) == 0 && S_ISDIR(st.st_mode)) {
+      File* file = file_create(fs);
+      if (!file) {
+        ok = false;
+      } else {
+        file->is_dir = true;
+        file->metadata =
+            file_metadata_create(fs, &st, config->preserve_atimes, config->preserve_crtimes);
+        file->send_path = str_dup(prefix);
+        if (!file->metadata || !file->send_path || !array_list_add(dir_entries, file)) {
+          file_destroy(file);
+          ok = false;
+        }
+      }
+    }
+    *p = saved;
+  }
+  free(fs);
+  free(prefix);
+  return ok;
 }
 
 /* True when some --files-from entry is an ancestor-or-equal directory of
@@ -2098,6 +2192,11 @@ static int scan_directory_multithreaded(void* pipeline_context) {
      parallel workers append under the context's dedicated mutex. */
   prepared.options.dir_entries = context->dir_entries;
   prepared.options.dir_entries_mutex = &context->dir_entries_mutex;
+  if (!append_implied_dir_times(context->config, context->dir_entries)) {
+    pipeline_cancel(context);
+    protocol_session_unbind();
+    return thrd_error;
+  }
   /* The keep-set manifest for the late modes is built from this data pass, so
      the parallel scanner records the protected excluded prefixes and the
      synchronized directories here (the size-prune protection is collected in
@@ -2434,6 +2533,8 @@ int send_files(Config* config) {
     dir_entries = array_list_create(file_destroy);
     if (!dir_entries)
       goto send_fail;
+    if (!append_implied_dir_times(config, dir_entries))
+      goto send_fail;
   }
   if (config->remove_source_files)
     remove_sources = array_list_create(source_file_destroy);

src/client/scanner.c

@@ -220,6 +220,44 @@ char* scanner_path_relative(const char* root, const char* fs_path) {
   return str_dup(fs_path + root_len + 1);
 }
 
+/* -R/--relative destination-relative prefix reconstructed from a source spec:
+ * everything after the first '.' path component (rsync's '/./' cut point),
+ * with leading/trailing slashes removed; or the whole spec (normalized) when
+ * there is no cut.  Returns "" for the receive root.  Exposed for tests. */
+char* scanner_relative_prefix(const char* spec) {
+  if (!spec || spec[0] == '\0')
+    return NULL;
+  const char* after = spec;
+  if (spec[0] == '.' && spec[1] == '/') {
+    after = spec + 2;
+  } else {
+    const char* cut = strstr(spec, "/./");
+    if (cut)
+      after = cut + 3;
+  }
+  size_t cap = strlen(spec) + 1;
+  char* out = malloc(cap);
+  if (!out)
+    return NULL;
+  size_t len = 0;
+  for (const char* s = after; *s;) {
+    while (*s == '/')
+      s++;
+    const char* comp = s;
+    while (*s && *s != '/')
+      s++;
+    size_t clen = (size_t)(s - comp);
+    if (clen == 0 || (clen == 1 && comp[0] == '.'))
+      continue;
+    if (len)
+      out[len++] = '/';
+    memcpy(out + len, comp, clen);
+    len += clen;
+  }
+  out[len] = '\0';
+  return out;
+}
+
 /* Relative path of a child entry below the current directory. */
 static char* child_rel_path(const char* parent_rel, const char* name) {
   if (!parent_rel || parent_rel[0] == '\0')
@@ -227,6 +265,15 @@ static char* child_rel_path(const char* parent_rel, const char* name) {
   return path_cat(parent_rel, name);
 }
 
+/* Destination-relative wire path for an entry under an -R prefix. */
+static char* scanner_prefix_send_path(const char* prefix, const char* rel) {
+  if (prefix[0] == '\0')
+    return str_dup(rel);
+  if (rel[0] == '\0')
+    return str_dup(prefix);
+  return path_cat(prefix, rel);
+}
+
 /* Apply the --files-from allow-set and the filter layer to one entry. */
 static bool entry_passes_selection(const FileListSet* file_list, const FilterRuleList* base,
                                    const FilterNode* node, const char* rel, const char* leaf,
@@ -367,12 +414,25 @@ static bool scanner_record_synced_dir(const ScannerOptions* options, const char*
     return true;
   if (!file_list_dir_in_scope(options->file_list, rel))
     return true;
-  const char* dest = relative_mode ? rel : fs_path;
+  char* prefixed = NULL;
+  const char* dest;
+  if (relative_mode) {
+    dest = rel;
+  } else if (options->relative_prefix) {
+    prefixed = scanner_prefix_send_path(options->relative_prefix, rel);
+    if (!prefixed)
+      return false;
+    dest = prefixed;
+  } else {
+    dest = fs_path;
+  }
   if (dest[0] == '/')
     dest++;
   if (dest[0] == '\0')
     dest = ".";
-  return excluded_sink_append(options->synced_dirs, options->excluded_mutex, dest);
+  bool ok = excluded_sink_append(options->synced_dirs, options->excluded_mutex, dest);
+  free(prefixed);
+  return ok;
 }
 
 /* Merge the open directory's own .rsync-filter rules into the inherited
@@ -672,7 +732,8 @@ static Chunk* chunk_data_to_chunk(ArrayList* chunk_data) {
  * non-directory path is silently skipped (the transfer is unaffected); an
  * allocation failure is fatal and reported to the caller. */
 static bool scanner_capture_dir_time(ArrayList* dir_entries, mtx_t* mutex, const char* root_path,
-                                     const char* fs_path, bool relative_mode, bool preserve_atimes,
+                                     const char* fs_path, bool relative_mode,
+                                     const char* relative_prefix, bool preserve_atimes,
                                      bool preserve_crtimes, bool preserve_xattrs,
                                      bool preserve_acls) {
   if (!dir_entries || !root_path || !fs_path)
@@ -689,14 +750,30 @@ static bool scanner_capture_dir_time(ArrayList* dir_entries, mtx_t* mutex, const
     free(rel);
     return true;
   }
+  char* prefixed = NULL;
+  if (relative_prefix) {
+    prefixed = scanner_prefix_send_path(relative_prefix, rel);
+    if (!prefixed) {
+      free(rel);
+      return false;
+    }
+    if (prefixed[0] == '\0') {
+      /* -R with a cut at the receive root: the root itself has no wire path. */
+      free(prefixed);
+      free(rel);
+      return true;
+    }
+  }
   File* file = file_create(fs_path);
   if (!file) {
+    free(prefixed);
     free(rel);
     return false;
   }
   file->is_dir = true;
   file->metadata = file_metadata_create(fs_path, &st, preserve_atimes, preserve_crtimes);
   if (!file->metadata) {
+    free(prefixed);
     free(rel);
     file_destroy(file);
     return false;
@@ -709,7 +786,11 @@ static bool scanner_capture_dir_time(ArrayList* dir_entries, mtx_t* mutex, const
   if (relative_mode) {
     file->send_path = rel;
     rel = NULL;
+  } else if (prefixed) {
+    file->send_path = prefixed;
+    prefixed = NULL;
   }
+  free(prefixed);
   free(rel);
   bool added;
   if (mutex) {
@@ -807,9 +888,9 @@ static int open_next_directory(DirectoryScanner* scanner) {
     if (scanner->options.capture_dir_times &&
         !scanner_capture_dir_time(
             scanner->options.dir_entries, scanner->options.dir_entries_mutex, scanner->root_path,
-            scanner->current_path, scanner->relative_mode, scanner->options.preserve_atimes,
-            scanner->options.preserve_crtimes, scanner->options.preserve_xattrs,
-            scanner->options.preserve_acls)) {
+            scanner->current_path, scanner->relative_mode, scanner->options.relative_prefix,
+            scanner->options.preserve_atimes, scanner->options.preserve_crtimes,
+            scanner->options.preserve_xattrs, scanner->options.preserve_acls)) {
       closedir(scanner->current_dir);
       scanner->current_dir = NULL;
       free(scanner->current_path);
@@ -1175,14 +1256,28 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner) {
          wire paths are never recorded (see ScannerOptions.excluded_paths). */
       bool files_from_prune =
           scanner->options.file_list && !file_list_affects(scanner->options.file_list, rel);
-      if (!files_from_prune && !scanner->relative_mode)
+      if (!files_from_prune && !scanner->relative_mode) {
+        if (scanner->options.relative_prefix) {
+          char* wrel = scanner_prefix_send_path(scanner->options.relative_prefix, rel);
+          if (!wrel) {
+            free(rel);
+            free(cur_path);
+            scanner->failed = true;
+            break;
+          }
+          scanner_record_excluded(scanner, wrel);
+          free(wrel);
+        } else {
           scanner_record_excluded(scanner, cur_path);
         }
-    /* With -R + --files-from the wire/destination path is the entry's bare
-       relative path; keep `rel` alive to attach it to a transferred file. */
-    char* rel_copy = scanner->relative_mode ? str_dup(rel) : NULL;
+      }
+    }
+    /* With -R the wire/destination path is a reconstructed relative path, not
+       the source path; keep `rel` alive to build it for a transferred file. */
+    bool needs_rel = scanner->relative_mode || scanner->options.relative_prefix != NULL;
+    char* rel_copy = needs_rel ? str_dup(rel) : NULL;
     free(rel);
-    if (rel_copy == NULL && scanner->relative_mode) {
+    if (rel_copy == NULL && needs_rel) {
       free(cur_path);
       scanner->failed = true;
       break;
@@ -1257,6 +1352,15 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner) {
       if (scanner->relative_mode) {
         file->send_path = rel_copy;
         rel_copy = NULL;
+      } else if (scanner->options.relative_prefix) {
+        file->send_path = scanner_prefix_send_path(scanner->options.relative_prefix, rel_copy);
+        free(rel_copy);
+        rel_copy = NULL;
+        if (!file->send_path) {
+          file_destroy(file);
+          scanner->failed = true;
+          break;
+        }
       }
       /* --devices/--specials: a device/FIFO/socket entry marked for preservation
          becomes a node to recreate (is_special, no data, rdev captured); an
@@ -1536,6 +1640,15 @@ static void scan_root_entry(const ScannerOptions* options, const FilterNode* roo
       if (options->relative && options->file_list != NULL) {
         if (!excluded_sink_append(sink, options->excluded_mutex, entry->d_name))
           ps->failed = true;
+      } else if (options->relative_prefix) {
+        char* wrel = scanner_prefix_send_path(options->relative_prefix, entry->d_name);
+        if (!wrel) {
+          ps->failed = true;
+        } else {
+          if (!excluded_sink_append(sink, options->excluded_mutex, wrel))
+            ps->failed = true;
+          free(wrel);
+        }
       } else {
         char* abs_path = path_cat(root_directory, entry->d_name);
         if (!abs_path) {
@@ -1577,13 +1690,13 @@ static void scan_root_entry(const ScannerOptions* options, const FilterNode* roo
     return;
   }
   if (is_dir) {
-    free(rel);
     if (!scanner_same_filesystem(options->one_file_system, root_dev, st.st_dev)) {
       /* -x/--one-file-system: emit the mount-point directory entry (empty) but
          do not descend into it (see the sequential scanner for the same rule). */
       File* mount = file_create(cur_path);
       free(cur_path);
       if (mount == NULL) {
+        free(rel);
         ps->failed = true;
         return;
       }
@@ -1592,17 +1705,29 @@ static void scan_root_entry(const ScannerOptions* options, const FilterNode* roo
         mount->metadata = file_metadata_create(mount->path, &st, options->preserve_atimes,
                                                options->preserve_crtimes);
         if (!mount->metadata) {
+          free(rel);
           file_destroy(mount);
           ps->failed = true;
           return;
         }
       }
+      if (options->relative_prefix) {
+        mount->send_path = scanner_prefix_send_path(options->relative_prefix, rel);
+        if (!mount->send_path) {
+          free(rel);
+          file_destroy(mount);
+          ps->failed = true;
+          return;
+        }
+      }
+      free(rel);
       if (!array_list_add(root_files, mount)) {
         file_destroy(mount);
         ps->failed = true;
       }
       return;
     }
+    free(rel);
     if (!array_list_add(subdirs, cur_path)) {
       free(cur_path);
       ps->failed = true;
@@ -1628,6 +1753,15 @@ static void scan_root_entry(const ScannerOptions* options, const FilterNode* roo
   if (use_rel) {
     file->send_path = rel;
     rel = NULL;
+  } else if (options->relative_prefix) {
+    file->send_path = scanner_prefix_send_path(options->relative_prefix, rel);
+    free(rel);
+    rel = NULL;
+    if (!file->send_path) {
+      file_destroy(file);
+      ps->failed = true;
+      return;
+    }
   }
   ScannerSpecial special = scanner_prepare_special(
       options->preserve_devices, options->preserve_specials, options->copy_devices, file, &st);
@@ -1857,8 +1991,9 @@ ParallelScanner* parallel_scanner_create_with_options(const char* root_directory
   if (options->capture_dir_times &&
       !scanner_capture_dir_time(options->dir_entries, options->dir_entries_mutex, root_directory,
                                 root_directory, options->relative && options->file_list != NULL,
-                                options->preserve_atimes, options->preserve_crtimes,
-                                options->preserve_xattrs, options->preserve_acls)) {
+                                options->relative_prefix, options->preserve_atimes,
+                                options->preserve_crtimes, options->preserve_xattrs,
+                                options->preserve_acls)) {
     array_list_delete(root_files);
     array_list_delete(subdirs);
     parallel_scanner_destroy(ps);

src/client/scanner.h

@@ -65,6 +65,11 @@ typedef struct {
   bool per_dir_filters;               /* -F: read .rsync-filter per directory */
   bool dirs;                          /* -d/--dirs: transfer dir entries, no recursion */
   bool relative;                      /* -R/--relative (dest rel paths, with --files-from) */
+  /* -R/--relative outside --files-from: the destination-relative path prefix
+   * reconstructed from the source spec (rsync's '/./' cut point), or NULL when
+   * -R is off or --files-from is in use (the bare-relative path then comes from
+   * the listed entry).  Borrowed read-only; owned by client_send. */
+  const char* relative_prefix;
   /* --list-only: emit an is_dir File for every traversed directory (the listing
    * includes directory entries, matching rsync).  Client-only; never set on a
    * real transfer, which relies on implicit parent creation. */
@@ -213,6 +218,13 @@ bool scanner_same_filesystem(bool one_file_system, dev_t root_device, dev_t entr
  * "/". Exposed so tests can exercise the mapping directly. */
 char* scanner_path_relative(const char* root, const char* fs_path);
 
+/* -R/--relative destination-relative prefix reconstructed from a source spec:
+ * the path after rsync's first '.' path component (the '/./' cut point), with
+ * leading/trailing slashes removed, or the whole spec (normalized) when there
+ * is no cut.  Returns "" for the receive root, or NULL when `spec` is NULL or
+ * allocation fails.  Exposed so tests can exercise the mapping directly. */
+char* scanner_relative_prefix(const char* spec);
+
 ParallelScanner* parallel_scanner_create_with_options(const char* root_directory,
                                                       const ScannerOptions* options,
                                                       ProtocolSession* allocation_session);

tests/test_scanner.c

@@ -1069,6 +1069,59 @@ static void test_scanner_path_relative() {
   EXPECT_NULL(scanner_path_relative("/tmp/foo", "/tmp/foobar"));
 }
 
+/* -R/--relative destination prefix: the '/./' cut point and normalization. */
+static void test_scanner_relative_prefix() {
+  char* p = NULL;
+
+  /* No cut: the whole spec with leading/trailing slashes removed. */
+  p = scanner_relative_prefix("/tmp/src/foo/");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "tmp/src/foo");
+  free(p);
+
+  p = scanner_relative_prefix("src/foo");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "src/foo");
+  free(p);
+
+  /* Trailing "/." is the directory itself, not a cut. */
+  p = scanner_relative_prefix("src/foo/.");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "src/foo");
+  free(p);
+
+  /* The first "/./" cuts everything before it. */
+  p = scanner_relative_prefix("/a/./b/c");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "b/c");
+  free(p);
+
+  p = scanner_relative_prefix("src/./");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "");
+  free(p);
+
+  /* A later "." component is normalized away. */
+  p = scanner_relative_prefix("a/./b/./c");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "b/c");
+  free(p);
+
+  /* A leading "./" is the cut at the start. */
+  p = scanner_relative_prefix("./s2");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "s2");
+  free(p);
+
+  p = scanner_relative_prefix(".");
+  EXPECT_NOT_NULL(p);
+  EXPECT_EQ_STR(p, "");
+  free(p);
+
+  EXPECT_NULL(scanner_relative_prefix(NULL));
+  EXPECT_NULL(scanner_relative_prefix(""));
+}
+
 /* rsync precedence: a deeper .rsync-filter overrides a shallower one, so an
  * inner "+ *.tmp" re-includes what the outer "- *.tmp" excluded. */
 static void test_per_dir_filter_override(bool parallel) {
@@ -1607,6 +1660,7 @@ void test_scanner() {
   test_per_dir_filter(false);
   test_per_dir_filter(true);
   test_scanner_path_relative();
+  test_scanner_relative_prefix();
   test_per_dir_filter_override(false);
   test_per_dir_filter_override(true);
   test_dirs_no_descent();