Unit: CLI parse + imply relationships (delete-missing implies ignore, not
delete; valid with --delete and delete timing); delete_missing_args config wire
round-trip (ignore_missing_args confirmed client-only); three-section manifest
round-trip and third-section traversal rejection; manifest_delete_missing_args
exact-path semantics; commit-time parking. Existing two-section manifest frames
updated to the three-section format. Integration: default missing entry is a
hard pre-transfer error; --ignore-missing-args transfers the rest and succeeds
(all-missing transfers nothing; empty list still errors); --delete-missing-args
removes exactly the missing mirror and leaves unrelated extras unless --delete is
also present; filter-exclusion protection never blocks the explicit deletion;
--delete-before early timing composes; all parametrized single-threaded vs -m.
- ignore-errors scan-error test now runs single-threaded and under -m (the
exact scan_directory_multithreaded path that had the use-after-free);
- new integration test: --delete/--delete-before --ignore-errors with an
unreadable SOURCE ROOT (sequential and -m) must fail and delete NOTHING;
- new integration test: a destination-only file that merely matches an exclude
rule is deleted under plain --delete (protection is sender-derived), while a
source-excluded mirror is protected;
- delete-protects/delete-excluded coverage extended to --delete-after and
--delete-delay;
- new unit test: the 100000-entry server hard bound is all-or-nothing (more
extras than the bound -> nothing removed);
- new integration test: --force is inert under --delay-updates (documented);
- fixed the ignore-errors assertion message that stated the opposite of what it
asserted.
Unit (CLI): --fuzzy --no-incremental (either order) stays a valid plain-mode
config -- no forced handshake, no delta implication; --fuzzy --no-delta stays
covered.
Integration (TestFuzzy):
- worthless basis: a sibling that passes the name+size gates but shares no
blocks makes the sender reply STATUS_NEXT; the whole file is consumed inside
the delta handshake with byte-exact output (no protocol desync).
- non-displacement: an existing exact-path destination file INSIDE the delta
size bounds (same size, different content, older mtime) is used as the delta
basis instead of a byte-identical similar sibling (whole-file wire cost).
- asymmetric bases: basis larger than source (prefix reuse) and basis smaller
than source (appended tail as literals) both reconstruct byte-exactly with a
small delta.
- --no-fuzzy end-to-end equals the no-flag whole-file behavior.
CountingProxy closes its listener socket (fd hygiene).
Unit: walker all-or-nothing bounds (exceeded -> nothing removed + distinct
result; exact bound -> deletes), protected-prefix skipping, config wire
round-trip for force_delete/delete_excluded/prune_empty_dirs/max_delete, CLI
parse/validation for the new flags. Integration (TestDeletePolicy): default
delete-excluded protection and --delete-excluded opt-out (single-thread, -m,
early --delete-before, excluded-dir subtrees), --max-delete all-or-nothing over
and at the limit, --force file-over-nonempty-dir replacement, --prune-empty-dirs
(--dirs mode + recursion-mode parity), and --ignore-errors keeping deletion
active across a genuine scan I/O error (run as an unprivileged user).
Unit: parse -y/--fuzzy and --no-fuzzy negation (order-independent), -W and
--no-delta leave fuzzy inert, --fuzzy implies --incremental/--delta, and
validate_config rejects fuzzy with -s (chunk serialization) and -f
(sendfile). Config: fuzzy survives the socketpair wire round-trip.
Integration (TestFuzzy, byte counts via a new CountingProxy helper): the
rename case transfers a 2 MiB file in a few percent of its size with byte-
exact output under --fuzzy, while the no-fuzzy, no-candidate, dissimilar-
sibling and --whole-file runs send the whole file; -y alias; -m parity;
dest-holds-unsuitable-file falls back to the sibling; --delay-updates and
--remove-source-files keep their semantics on fuzzy transfers.
The seed run did not preserve timestamps, so the destination copy's mtime was
the write time; the incremental --remove-source-files rerun only skipped the
file when both writes happened to land in the same whole second, making the
test flaky (observed intermittently in local full-suite runs and on CI). Seed
with -M so the destination stores the source's exact mtime.
- unit: config basis-path normalization (trailing slash, a//b, ./x/./y collapse;
degenerate inputs rejected).
- integration: same-size/same-mtime/different-content fixtures prove the xxHash
gate -- the basis changed.txt now has the SAME byte size as the source so the
size short-circuit can no longer mask the hash comparison, plus a dedicated
parametrized same-size mismatch test asserting link/copy never use a
content-mismatched basis and compare-dest transfers.
- basis-dir priority is first-match-wins: two link-dest dirs (inode of the
first), and compare-dest before link-dest stays sparse while the reverse
order hard-links.
- --size-only links a same-content basis file with a different mtime;
--ignore-times never links even an exact match.
- --delay-updates + --delete removes extras inside a nested .fastsync-stage
dir (regression guard) while keeping the real staging dir and basis tree.
- a basis run containing a file above the whole-file limit fails up front with
a clear error and transfers nothing.
- Unit (leak guards): drive receiver_process_pending() past a parked keep-set
into STATUS_ABORT, EOF, and a second manifest frame; each must return -1 with
no manifest handed out. Verified leak-free under ASan.
- Unit: receive_status_timed reads a status and fails cleanly on EOF.
- Integration: test_late_flags_commit_only_after_success now parametrizes the
-m path, proving a failed -m late-timing run preserves every extra and that
the deferred manifest is dropped (never applied) when the writer fails.
- CLI: each timing flag (+ --del alias) accepted and implies --delete;
conflicting timings and a timing with --no-delete are rejected.
- Config: delete_during/delete_delay survive config_send/config_receive;
two simultaneous timings are rejected by the receiver-side validation;
config_delete_timing_early() mapping is unit-tested.
- Integration (TCP, single- and multithreaded): every flag removes extras on
a successful transfer; early modes (--delete-before/--delete-during/--del)
delete before data is applied so a destination file blocking a nested
write is removed and the transfer succeeds, while plain --delete /
--delete-after / --delete-delay keep it and fail with every extra intact
(commit-style). Early timing also completes (without deleting) when the
server refuses deletion.
Deletion timing is now real and selected by the four rsync flags plus the
plain --delete default. Wire protocol bumps to 2.8.0: two new config
booleans (delete_during, delete_delay) are serialized and validated, joining
the existing delete_before/delete_after.
- Early modes (--delete-before, --delete-during/--del): the sender pre-scans
the whole tree (paths only), transmits the keep-set manifest BEFORE any
file data, and the receiver removes extras and acks STATUS_OK; the sender
only streams data after the deletion committed. Deletion is thus performed
even if a later transfer phase fails (rsync delete-before/during are
destructive by definition). FastSync streams in a single scan so it cannot
interleave per-directory like rsync delete-during; --delete-during selects
the same engine mode as --delete-before (documented divergence).
- Late/commit modes (plain --delete, --delete-after, --delete-delay): the
manifest closes the data stream and deletion is committed only after
STATUS_FINISHED proves the whole transfer succeeded, preserving FastSync's
commit-style safety. --delete-delay converges with --delete-after because
FastSync never snapshots the destination during data flow (documented).
- The STATUS_MANIFEST frame is now self-delimiting and position-independent.
Single-threaded receivers delete before the success frame; the -m receiver
hands the keep-set to server.c, which commits the deletion only after the
disk writer thread has drained (fixes a delete-vs-in-flight-temp race).
- Every timing flag implies --delete; at most one timing flag is allowed.
- Each timing flag implies --delete, matching rsync; conflicts are rejected.
- compare-dest skips an exact basis match (leaving a sparse destination) and
still transfers files the basis cannot satisfy; a content mismatch forces a
normal transfer.
- copy-dest materializes the unchanged file as a real local copy (distinct
inode) and transfers content mismatches.
- link-dest hard-links (asserted same inode/nlink to the DIR file) and falls
back to a normal transfer on content mismatch.
- a missing basis dir is a clean full-transfer no-op for all three flags.
- link-dest works through -m multithreading and --delay-updates (staged and
published as a real link, staging cleaned up).
- --delete removes genuine extras while leaving the basis dir untouched.
- parse_args accepts each flag in both forms, keeps repetition order/types,
implies --incremental + metadata, and rejects absolute/escaping/degenerate
paths; validate_config rejects basis dirs combined with -s.
- config wire round-trips a mixed basis list and rejects escaping/absolute
paths on the receiver side.
After the writer releases bytes, the blocked enqueuer may already have
admitted the next payload, so the transient queued_bytes==0 read is
scheduling-dependent (lost the race under ASan). The post-join state
(covers unblocking + budget re-limit) is deterministic.
B1: destination-root existence/creation mishandled two legitimate forms.
file_directory_exists_secure/file_ensure_directory_secure now normalize a
trailing-slash destination (so the last component is never an empty leaf)
and treat a destination equal to the already-open authorized root as present
(no spurious <root>/<basename> nested dir with --mkpath). Confinement and
O_NOFOLLOW probing are unchanged. Regression integration tests: existing
dest with trailing slash works with and without --mkpath; dest == authorized
root works and creates no stray nested dir.
W1: chunk serialize/deserialize round-trip unit test for a directory entry
mixed with a regular file, with and without metadata; --dirs coverage under
-s and -s -m.
W2: --list-only and --dry-run now print file_wire_path() so all outputs show
the -R transformed relative name, matching -i/--out-format.
W3: RSYNC_COMPAT -d/--dirs note: dirs are created immediately under
--delay-updates (only regular files are staged).
W4: --dirs generator flushes chunks by element count too, so a long
--files-from list of empty directories cannot exceed the per-chunk file cap.
N1: STATUS_MKDIR added to status_to_string.
N2: removed dead TestMkpath._transfer.
N3: removed redundant --no-implied-dirs OPTION_TABLE row.
N4: integration tests: --dirs --delete keeps the just-created empty dir (and
deletes extras); a listed dir colliding with a regular file at the dest fails
cleanly.
RSYNC_COMPAT Phase-2 row M: path-list construction and destination
directory creation while preserving traversal safety.
- -R/--relative with --files-from: transmit each listed entry under its
bare relative destination path (no source-root mirror). Files keep an
absolute local read path plus a separate wire/dest path (File.send_path);
manifest, incremental quick-check and change output follow the wire path,
so --delete and --remove-source-files stay consistent. -R without
--files-from is unchanged (full mirror).
- --no-implied-dirs: client-only, only meaningful with -R + --files-from.
A listed file whose parent dir is not itself (or via an ancestor)
explicitly listed cannot be placed; the run fails up front with a clear
error. No effect otherwise.
- --dirs/-d + --old-dirs/--old-d aliases: -d <dir> transmits the source
root as an explicit empty directory entry (STATUS_MKDIR frame); with
--files-from listed dirs are created empty and listed files transferred,
never descending. Works single-threaded, -m (sequential scanner in the
-m scan thread) and chunk-serialization (per-file type marker).
Directory entries appear in the delete manifest.
- --mkpath: new wire bool; server creates the destination root (and missing
leading components under its authorized root) at connection start. A
missing destination root is now rejected by default.
- Protocol bumped to 2.7.0 (mkpath wire field + STATUS_MKDIR + chunk type
marker). All receive paths funnel through file_save_to_disk_full which
creates directories via the secure confined mkdir engine; dir entries are
excluded from --remove-source-files outcome acknowledgements on both ends.
- Unit coverage: CLI parse (relative/dirs aliases/mkpath/no-implied-dirs),
config round-trip (relative + mkpath), scanner --dirs non-recursion and
-R send_path (sequential + parallel), receiver dir-entry save.
- Integration coverage: TestRelativeFilesFrom, TestNoImpliedDirs, TestDirs,
TestMkpath (single and -m).
- RSYNC_COMPAT: 4 rows move to Implemented (Summary 67/3/5/1/71 = 147).
Review fixes for --delay-updates:
- --delete no longer deletes the staged files: the delete walker gains a
skip_root_child parameter and receive_manifest passes DELAY_UPDATES_STAGING_DIR
when delay_updates is active, so deletion removes genuine extras while the
staging dir (a direct child of the receive root) is left for publication in
both single and -m modes.
- --backup-dir is rejected when it collides with the reserved internal staging
name .fastsync-stage (trailing slash normalized), in client validation and in
the received-config wire validation, preventing old backups from being
silently installed as new files.
- Staging dir is now held under an exclusive advisory flock for the whole
transfer (context lifetime): two simultaneous delayed transfers to one
destination root no longer share/destroy each other's staged data - the
second fails cleanly. Cleanup only touches the staging dir when this context
owns the lock, so a lock-contention failure cannot wipe a live session.
- Post-publish staging cleanup now returns/logs instead of discarding failures
(warning when the staging dir cannot be fully removed).
- Reworked the publish-failure integration test to exercise real mid-publish
semantics (top-level file published, nested rename fails, no rollback,
sources retained under --remove-source-files) and added integration tests for
--delete + --delay-updates ordering and reserved --backup-dir rejection.
- RSYNC_COMPAT note documents delete ordering, the reserved-name hazard, and
the concurrency guard.
Address an independent c-review of the files-from/filter feature:
- .rsync-filter precedence now matches rsync: evaluate the innermost
(current) directory's rules first, then ancestors, then the command-line
base (--filter/-C), so a deeper file's '+' can re-include what a shallower
'-' excluded (regression tests in both scan modes; single-thread and -m).
- --files-from: a listed entry missing on disk and an empty list are now hard
errors surfaced pre-transfer in send_files, send_files_multithreaded,
dry-run and --list-only; '.' (whole tree) and empty listed dirs stay valid.
- scanner_path_relative now handles a transfer root of / (previously the
scanner aborted on children of /).
- Reject unsupported rsync filter syntax explicitly (no silent no-ops):
+/- modifiers other than '/' (! C s r p x) and rules beginning with ':'/'.'
/'!' (merge/dir-merge/list-clear shorthands). Docs updated.
- -0/--from0 NUL mode preserves entry bytes (no CR/LF trimming); only newline
mode trims. Absolute-entry error message no longer includes the newline.
- --no-from0/--no-cvs-exclude registered as negatable booleans.
- RSYNC_COMPAT rows updated for the precedence, rejection list, NUL-mode
detail and the documented O(entries x files) scalability bound of the
allow-set (Summary unchanged: 62/3/5/1/76 = 147).
Implement the RSYNC_COMPAT Phase-2 filter/parser feature group:
- --files-from=FILE (repeatable) plus -0/--from0 NUL delimiters: parse the
source file list relative to the source root into a shared read-only
allow-set; the scanner transfers listed files and the whole subtree of
listed directories and prunes everything else in single- and
multithreaded mode. Absolute/'..' entries and missing files are hard
CLI errors.
- --filter=RULE: rsync-style +/- rules (anchored '/', dir-only trailing '/',
word include/exclude forms) evaluated first-match-wins with a default of
include, as an independent layer from legacy --exclude/--include.
Unsupported directives (merge/hide/... ) are rejected explicitly. -f stays
sendfile.
- -C/--cvs-exclude: well-known rsync CVS default exclude set.
- -F: per-directory .rsync-filter files read during traversal and applied to
the owning directory's subtree (single + parallel), never transferred.
- Delete manifest still derives from what was actually sent.
Client-only config fields; no wire/protocol change. Adds unit coverage
(CLI parse, allow-set and filter scanning single+parallel) and integration
tests (TestFilesFrom, TestFilters). RSYNC_COMPAT matrix rows updated:
5 rows move to Implemented (Summary 62/3/5/1/76 = 147).
Stage every successfully written file under a private 0700 .fastsync-stage
directory inside the receive root and atomically publish all staged files
only after the whole protocol stream (manifest/delete handling included)
has completed, immediately before the success/outcome frame. On any
abort/error before publication nothing is installed and staging is removed;
a publish failure aborts the transfer with best-effort cleanup of the
remainder (already-published files are not rolled back). Crash leftovers
are wiped when the next delayed transfer starts.
Wire: new delay_updates config flag (selection-options block), protocol
version bumped to 2.6.0, client/server validation rejects --inplace.
CLI/usage/validation updated. Works in single-threaded and -m modes
(exactly one write_thread stages files; the staged-file registry is
mutex-protected; publication runs once after both threads join).
--existing/--ignore-existing/--update decide against the final destination
at stage time; --backup is deferred to publication. remove_source_files
outcomes are only sent after publication so skipped/unpublished sources are
never deleted. Default (no flag) behavior is unchanged.
Tests: config wire round-trip, CLI parse, --inplace rejection, new
test_delay_updates unit suite (27 suites total), and integration
TestDelayUpdates covering single/-m parity, incremental reruns, remove
source files, receiver-skip ordering, and a deterministic publish-failure
abort path.
Receiver writes temps into a confined scratch dir and atomically renames
into place; EXDEV aborts; inplace/partial bypass; thread-safe temp names.
Uses existing wire field; no protocol bump. Reviewed (c-review APPROVE
WITH NITS, all fixed); PR #262.
Address c-review nits on the itemize/output feature:
- RSYNC_COMPAT.md: state that %b is the source length (always == %l) because
no wire-byte counter exists; keep Summary equal to the matrix (recounted:
54 implemented / 84 not-implemented, 147 rows total - four rows flipped).
- change_list.h/.c: document bytes_sent == size; note itemize/out-format lines
never interleave with each other but may interleave with legacy log
messages sharing the stream; mark the %M stat() path best-effort.
- change_render_format scan in format_uses_mtime now mirrors the tokenizer
(skips '%%' and unknown '%X' pairs) so a literal '%%M' no longer triggers
the stat() fallback.
- Integration tests: --list-only under -m; a changed file on a second
--incremental run emits exactly one '>f' line while unchanged files print
nothing; --log-file + --log-file-format under -m.
Add a rootless unit test that reaches the actual st_dev skip branch in both
the sequential and parallel (-m) scanners: a symlink nested under the scan
root points at a directory on /dev/shm (a different device than the build
fs) and, under --copy-links semantics, -x must drop that subtree while a
plain scan includes it. Skips only when no cross-device target exists.
Integration OneFileSystem test now cleans both dest dirs up front and
reports a busy test mountpoint instead of ignoring the umount result.
RSYNC_COMPAT.md notes that cross-filesystem mount-point subdirectories are
dropped entirely (rsync parity).
Implement rsync-style itemized output backed by one shared change-event
engine (src/client/change_list.c):
- -i/--itemize-changes prints ">f+++++++++ <path>" for files actually sent
(single-threaded and -m); unchanged files print nothing.
- --list-only prints an ls-style listing of files that would be transferred
without contacting the server or writing anything.
- --out-format=FORMAT prints a printf-style template per changed file
(tokens %%f %%n %%l %%b %%M %%%%; unknown escapes preserved).
- --log-file-format=FMT logs each transferred file when --log-file is set.
Events are emitted from the per-file sender path shared by both transfer
modes, so the single sender thread is the only reporter (no races).
Capture the transfer root's device (st_dev) at scanner creation and skip
descending into any subdirectory on a different device (a mount point).
Implemented sender/client-side only: sequential BFS and parallel (-m) root
scan apply the same scanner_same_filesystem decision; no wire/protocol change
and default behavior is unchanged. Unit tests cover the pure decision, same
device scanning in both modes, and CLI parsing; integration tests prove -x
leaves a single-filesystem tree byte-identical and, when root can mount a
tmpfs, skips a genuine cross-device subtree.
Review nits from independent review of the four fix branches:
- receive_delta_file STATUS_NEXT oversize branch now sets *failed=true
- receive_incremental_check oversize branch returns NULL (receiver sends the
single STATUS_ERROR) instead of double-sending
- add multithreaded -m --ignore-existing --remove-source-files integration
coverage so the writer-thread outcome path is exercised
- Correct misleading doc comments on set_string_option /
set_positive_int_option / set_nonneg_int_option (they return 0/-1,
not true/false).
- find_table_option_with_equals() now matches every OPTION_TABLE value
option (OPT_STRING/OPT_POS_INT/OPT_NONNEG_INT/OPT_ULL), so forms such
as --max-size=2G, --min-size=1K, --suffix=.bak, --timeout=30,
--max-depth=5, --backup-dir=X parse instead of dying as 'Unknown option'.
--max-size/--min-size now accept rsync-style binary suffixes (0 remains a
valid 'no limit' byte count). Existing special handling for
--compress-choice, --compress-level, --modify-window=, --chmod=,
--skip-compress=, --compress-threads= is preserved.
- Options that require a separate value (-p, --exclude, --include,
--delta-block, --delta-max, --server-port, --bwlimit, --chunk-size,
--log-file, --exclude-from, --include-from, -T, --skip-compress,
--compress-threads) now emit an explicit 'missing argument' diagnostic
instead of falling through to the generic 'Unknown option' branch when
given as the final argv entry.
- Add unit tests covering the = forms (--max-size=2G, --min-size=1K,
--suffix=.bak, --timeout=30, --max-depth=5, --backup-dir=X) and a clean
'missing argument' (not 'Unknown option') diagnostic for trailing
--exclude/--server-port/--skip-compress/-T.
- remove-source-files keeps sources skipped by --existing/--ignore-existing/
--update (rsync reference behavior)
- --backup keeps <file>~, --suffix .bak, and --backup-dir backups
- --partial --partial-dir installs completed files in the destination
- a 100 MB file transfers end to end (>64 MiB whole-file cap regression)
#251 --remove-source-files deletes sources that were skipped receiver-side
(--existing/--ignore-existing/--update). The receiver now reports a
per-file outcome for every processed data file when the sender requests
removal; the client only unlinks sources the receiver actually wrote.
add remove_source_files to the wire config and bump the protocol to 2.5.0.
#252 --backup/--suffix/--backup-dir broken by NULL-vs-empty wire loss. Receivers
canonicalize the empty wire string back to NULL for backup_dir, temp_dir,
partial_dir and suffix, and --suffix is received unconditionally.
#253 --partial --partial-dir never installed completed files. file_save_to_disk
now renames a fully written partial-dir file into the real destination.
#255 STATUS_CHECK read the entire old file before the size/mtime quick check.
Old contents are only read when a checksum compare or delta needs them.
#256 receive_delta_file failure paths did not set *failed, so the caller sent
STATUS_NEXT and waited for a body that never came. Every NULL return now
marks the transfer failed.
#257 files >64 MiB could not transfer. Whole-file receive caps raised to the
256 MiB connection/allocation ceiling (chunk caps stay 64 MiB) and the
client ignores SIGPIPE so a server-side close surfaces as a clean error.
Unit tests added: config NULL-vs-empty round trip, incremental quick-check
skip/NEXT paths, delta oversize failure, partial-dir install, save-result
skip reporting.
The --inplace branch opened the destination with O_WRONLY|O_CREAT (no
O_TRUNC) and only restored metadata when the sender supplied it. Two
flaws resulted:
1. An existing destination file kept its original mode when no metadata
was sent, so setuid/setgid/sticky bits survived an overwrite (a root
sync could leave a root-owned setuid binary controlled by a client).
2. A shorter payload left stale trailing bytes from the previous version
because the file was never truncated to the new length.
In the inplace branch of file_to_disk_secure_impl:
- Always trim the file to the new payload length (ftruncate after the
write) so stale trailing bytes can never survive; sparse targets keep
their pre-size ftruncate.
- Always normalize the mode after a successful overwrite: apply the
metadata-derived safe mode when metadata is present (as before), else
fchmod to a safe default 0644, so setuid/setgid/sticky are cleared in
both cases.
- The --update newer-destination check still runs before any truncation
or chmod, preserving the skip semantics.
Adds unit tests in test_file.c: (a) setuid/sticky bits on an existing
destination are cleared after an inplace write with and without metadata,
(b) a shorter inplace payload leaves no trailing stale bytes.
The per-connection memory budget (MAX_CONNECTION_MEMORY, 256 MiB) only
charged wire buffers via receive_data_limited. Decompression buffers and
per-file chunk copies were not accounted for, and the multithreaded
receiver could enqueue up to 100 files (each up to 64 MiB uncompressed)
ahead of a slow disk writer, retaining ~6.4 GiB per connection. A client
sending highly compressible chunks with little bandwidth could OOM the
host while the reserve never tripped.
Bound the receive pipeline by aggregate payload bytes instead of item
count alone:
- Export MAX_CONNECTION_MEMORY from protocol.h.
- PipelineContextReceiver tracks queued_bytes (payload bytes received but
not yet released by the disk writer, i.e. queued or in the writer's
hand) under the existing mutex.
- receiver enqueue now blocks while the queue is full by count OR when
adding the file would push queued_bytes over the configured byte limit,
applying backpressure to the sender instead of failing the transfer.
- The disk writer releases the byte budget after each file is freed and
signals the not-full condition.
- The server sets the byte ceiling to
MAX_CONNECTION_MEMORY - 2*MAX_CHUNK_SIZE so that the queued payloads
plus the transient wire/decompression buffers of the one in-flight
chunk stay within the per-connection budget.
The single-threaded receive path is already bounded: it writes files to
disk before reading the next chunk, so its transient is at most one
chunk's wire + decompressed + copied payload (~3 * MAX_CHUNK_SIZE, below
the budget). Wire buffers remain charged exactly once by
receive_data_limited; this change does not double charge them.
Adds a deterministic unit test in test_multiprocessing.c proving that an
enqueue which would exceed the byte budget blocks until the writer
releases bytes.
The Phase 1 merge conflict resolutions introduced formatting that failed
the CI lint job (clang-format 18.1.3). Reformatted with the exact CI
version; no functional changes.
metadata_mtime_matches() required exact nanosecond equality at the default
modify_window=0, but destination write-time nsecs never match source
creation-time nsecs unless -M preserves metadata. Compare whole seconds
(rsync's default quick-check) at window 0; keep the subsecond-refined
tolerance for explicit window values.