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2026-08-24Merge branch 'en/diff-l-opt-help'Junio C Hamano1-1/+1
The help text for the '-l' option of 'git diff' has been updated. * en/diff-l-opt-help: diff: avoid misleading statement about -l option
2026-08-24Merge branch 'js/pack-objects-delta-size-t'Junio C Hamano1-2/+4
The 'pack-objects' and delta-encoding code paths have been updated to use 'size_t' instead of 'unsigned long' for object sizes and offset limits, avoiding potential truncation issues on 64-bit Windows. * js/pack-objects-delta-size-t: packfile: widen `unpack_object_header_buffer()` to `size_t` git-zlib: widen `git_deflate_bound()` to `size_t` t/helper/test-pack-deltas: widen `do_compress()`'s maxsize local to `size_t` http-push: widen `start_put()`'s size local from `ssize_t` to `size_t` diff: widen `deflate_it()`'s bound local from int to `size_t` archive-zip: widen `zlib_deflate_raw()`'s maxsize local to `size_t` packfile, git-zlib: widen `use_pack()` and zstream avail fields to `size_t` delta: widen `create_delta()` and `diff_delta()` to `size_t` pack-objects: widen `mem_usage` and `try_delta()`'s out-param to `size_t` pack-objects: widen `free_unpacked()` return to `size_t` pack-objects: widen delta-cache accounting to `size_t` delta: widen `create_delta_index()` parameter to `size_t` diff-delta: widen `struct delta_index`' size fields to `size_t`
2026-08-13diff: avoid misleading statement about -l optionElijah Newren1-1/+1
In commit 6623a528e00b (doc: clarify documentation for rename/copy limits, 2021-07-15), the wording around rename limit options and config variables were updated to point out that only the quadratic portion of rename detection (or "exhaustive portion of rename/copy detection" as used in that commit) was limited by these options, because exact rename detection and basename-guided rename detection (which both run in time linear in the number of files) still run before this limit is checked. However, the short help message wasn't updated at the time; update it too. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-08-13diff: widen `deflate_it()`'s bound local from int to `size_t`Johannes Schindelin1-1/+1
Fixes a pre-existing silent narrowing from `git_deflate_bound()`'s `unsigned long` return into an `int` local: anything past 2 GiB has always wrapped negative here and then been re-extended to `size_t` inside `xmalloc()`. Also prep for the upcoming `git_deflate_bound()` widening to `size_t`, which would extend the narrowing further if `bound` stayed `int`. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-08-13delta: widen `create_delta()` and `diff_delta()` to `size_t`Johannes Schindelin1-1/+3
Last stop in the delta-encoding API widening for >4 GiB blobs on Windows: with `create_delta_index()` done in the prior commit and `create_delta()`/`diff_delta()` finished here, every byte count that crosses delta.h is now `size_t`. The struct fields they store into have been `size_t` since the diff-delta struct widening. The API change must move with all callers in the same commit (the build only passes when every `&delta_size` matches the new `size_t*`). Caller updates are kept minimal: * builtin/pack-objects.c `get_delta()` and `try_delta()`: widen only the local `delta_size` variable; the surrounding unsigned-long locals and their `cast_size_t_to_ulong()` shims are out of scope here and will be cleaned up in their own commits. * builtin/fast-import.c, diff.c, t/helper/test-pack-deltas.c: keep the local unsigned-long delta size (each feeds a still- unsigned-long downstream consumer: zlib's `avail_in`, `deflate_it()`, the test helper's own `do_compress()`), and bridge via a temporary `size_t` plus `cast_size_t_to_ulong()`. The new casts are paid back in later topics that widen those consumers. * t/helper/test-delta.c: widen the local outright (no downstream consumer beyond the test's own `out_size`, which is already `size_t`). Note that GCC struggles a bit to figure out that `deltalen` is always initialized before it is used; To help it along, we initialize it to 0. This work-around will go away in a later patch series when `deltalen` can be widened to `size_t`. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-07-31merge-ll: consolidate conflict marker scanning logicJunio C Hamano1-24/+1
The diff.c:is_conflict_marker() and rerere.c:is_cmarker() functions implement duplicate logic for identifying conflict marker lines (lines that begin with a run of '<', '=', '>', and '|' characters). diff.c's original version from 049540435f (diff --check: detect leftover conflict markers, 2008-06-26) accepts any whitespace (such as a newline) immediately following '<<<<<<<' and '>>>>>>>', whereas rerere.c's version from 191f241717 (rerere: prepare for customizable conflict marker length, 2010-01-16) strictly requires a space character (' ') after them. Implement is_conflict_marker_line() in merge-ll.c to serve as a replacement for both, and update diff.c and rerere.c to use the new helper. The unified helper intentionally adopts rerere's stricter rule, as the conflicts generated by Git always show the "ours" and "theirs" labels after these markers separated by a space. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-07-07hash: use git_hash_init() consistentlyJeff King1-2/+2
We'd like to add more logic to git_hash_init(), but many callers skip it and call algop->init_fn() directly. Let's make sure we're consistently using the wrapper by adding a coccinelle rule. Besides the coccinelle file itself, this is a purely mechanical conversion based on the patch it generates. There should be no bare init_fn() calls left (except for the one in the wrapper). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-07-07Merge branch 'jk/hash-algo-leak-fixes' into jk/git-hash-cleanupsJunio C Hamano1-0/+1
* jk/hash-algo-leak-fixes: hash: add platform-specific discard functions hash: fix memory leak copying sha256 gcrypt handles http: discard hash in dumb-http http_object_request check_stream_oid(): discard hash on read error patch-id: discard hash when done csum-file: provide a function to release checkpoints csum-file: always finalize or discard hash hash: add discard primitive csum-file: drop discard_hashfile()
2026-07-02patch-id: discard hash when doneJeff King1-0/+1
When computing a patch-id, we have a flush_one_hunk() helper that calls git_hash_final() on our running hunk git_hash_ctx, and then reinitializes that context for the next hunk. When we run out of hunks to look at, we return, discarding the git_hash_ctx. This can cause a leak if the hash implementation we are using allocates any memory during its initialization. This includes OpenSSL >= 3.0, for both SHA-1 and SHA-256. Normally we would not use SHA-1 here at all, as we only recommend using non-DC implementations for the "unsafe" variant (and patch-id, though they probably _could_ use the unsafe variant, were never taught to do so). But it is certainly a problem for SHA-256, which you can see with: make SANITIZE=leak \ OPENSSL_SHA256=1 \ GIT_TEST_DEFAULT_HASH=sha256 \ test That results in leak failures of 60 scripts, 57 of which are fixed by this patch (basically anything which runs rebase will hit this case). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-21Merge branch 'js/objects-larger-than-4gb-on-windows-more'Junio C Hamano1-1/+4
* js/objects-larger-than-4gb-on-windows-more: odb: use size_t for object_info.sizep and the size APIs packfile,delta: drop the `cast_size_t_to_ulong()` wrappers pack-objects: use size_t for in-core object sizes packfile: widen unpack_entry()'s size out-parameter to size_t pack-objects(check_pack_inflate()): use size_t instead of unsigned long patch-delta: use size_t for sizes compat/msvc: use _chsize_s for ftruncate
2026-06-15odb: use size_t for object_info.sizep and the size APIsJohannes Schindelin1-1/+4
When `js/objects-larger-than-4gb-on-windows` widened the streaming, index-pack and unpack-objects code paths, in the interest of keeping the patches somewhat reasonably-sized, it left the public ODB API still typed in `unsigned long`. In particular `struct object_info::sizep` and the four wrappers built on top of it (`odb_read_object`, `odb_read_object_peeled`, `odb_read_object_info`, `odb_pretend_object`) still return the unpacked size through `unsigned long *`, so on Windows `cat-file -s` and the `git add` / `git status` paths for a >4 GiB blob silently cap at 4 GiB. Widen the field and the four wrappers. The previous commits already widened the `unpack_entry()` cascade and pack-objects' in-core size accessors, so most of the cascade arrives here with no further work: the temporary shims in `packed_object_info_with_index_pos()` and in `unpack_entry()`'s delta-base recovery path go away, the two `SET_SIZE(entry, cast_size_t_to_ulong(canonical_size))` calls in `check_object()` and the matching one in `drop_reused_delta()` collapse to plain `SET_SIZE`, and `oe_get_size_slow()`'s tail `cast_size_t_to_ulong()` is gone too. What remains narrow are the boundaries this series does not intend to touch: the diff, blame, textconv and fast-import machinery. Even so, this patch is unfortunately quite large. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-15Merge branch 'ob/more-repo-config-values'Junio C Hamano1-1/+2
Many core configuration variables have been migrated from global variables into 'repo_config_values' to tie them to a specific repository instance, avoiding cross-repository state leakage. * ob/more-repo-config-values: environment: move "warn_on_object_refname_ambiguity" into `struct repo_config_values` environment: move "sparse_expect_files_outside_of_patterns" into `struct repo_config_values` environment: move "core_sparse_checkout_cone" into `struct repo_config_values` environment: move "precomposed_unicode" into `struct repo_config_values` environment: move "pack_compression_level" into `struct repo_config_values` environment: move `zlib_compression_level` into `struct repo_config_values` environment: move "check_stat" into `struct repo_config_values` environment: move "trust_ctime" into `struct repo_config_values`
2026-06-03environment: move `zlib_compression_level` into `struct repo_config_values`Olamide Caleb Bello1-1/+2
The `zlib_compression_level` configuration is currently stored in the global variable `zlib_compression_level`, which makes it shared across repository instances within a single process. Store it instead in `repo_config_values`, where eagerly‑parsed repository configuration lives. `zlib_compression_level` is parsed eagerly because it determines compression behaviour for objects and packs – core operations where a lazy parse could lead to unpredictable results and hinder libification. This preserves the existing eager‑parsing behavior while tying the value to the repository it was read from, avoiding cross‑repository state leakage and continuing the effort to reduce reliance on global configuration state. Update all references to use `repo_config_values()`. Mentored-by: Christian Couder <christian.couder@gmail.com> Mentored-by: Usman Akinyemi <usmanakinyemi202@gmail.com> Signed-off-by: Olamide Caleb Bello <belkid98@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-05-25Merge branch 'mm/diff-U-takes-no-negative-values'Junio C Hamano1-11/+14
The command line parser for "git diff" learned a few options take only non-negative integers. * mm/diff-U-takes-no-negative-values: parse-options: clarify what "negated" means for PARSE_OPT_NONEG xdiff: guard against negative context lengths diff: reject negative values for -U/--unified diff: reject negative values for --inter-hunk-context
2026-05-13diff: reject negative values for -U/--unifiedMichael Montalbo1-4/+8
Passing a negative value to -U is silently accepted and produces corrupt unified diff output with malformed hunk headers: $ git log -1 -p -U-500 -- GIT-VERSION-GEN | grep '^@@' @@ -503,999- +503,999- @@ Line 503 of a 106-line file, count "999-" is not a valid integer. The config variable diff.context already rejects negative values, but the command line callback diff_opt_unified() uses strtol() with no range check. Change the type of diff_options.context and its static default from int to unsigned int, matching the change to interhunkcontext in the previous commit. The type change requires reworking the callback and config parsing to validate in a local variable before assigning to the now-unsigned field. Unlike --inter-hunk-context which could be converted to OPT_UNSIGNED, -U needs OPT_CALLBACK_F for PARSE_OPT_OPTARG (bare -U with no value enables patch output). Add a range check in the callback instead. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-05-13diff: reject negative values for --inter-hunk-contextMichael Montalbo1-7/+6
Negative values for --inter-hunk-context produce structurally invalid diff output with overlapping hunks: $ git log -1 -p -U3 --inter-hunk-context=-100 791aeddfa2 \ -- git-compat-util.h | grep '^@@' @@ -110,6 +110,9 @@ @@ -115,6 +118,9 @@ @@ -116,6 +122,7 @@ Hunk 1 covers lines 110-115, hunk 2 starts at 115 (overlap), hunk 3 starts at 116 (overlaps both). The resulting patch cannot be applied. The config variable diff.interHunkContext already rejects negative values, but the command line option does not. Change the type of diff_options.interhunkcontext and its static default from int to unsigned int, and switch the option parser from OPT_INTEGER_F to OPT_UNSIGNED. This rejects negative values at parse time via git_parse_unsigned() and enforces the correct type at compile time via BARF_UNLESS_UNSIGNED. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-04-20diff: fix out-of-bounds reads and NULL deref in diffstat UTF-8 truncationElijah Newren1-2/+24
f85b49f3d4a (diff: improve scaling of filenames in diffstat to handle UTF-8 chars, 2026-01-16) introduced a loop in show_stats() that calls utf8_width() repeatedly to skip leading characters until the displayed width fits. However, utf8_width() can return problematic values: - For invalid UTF-8 sequences, pick_one_utf8_char() sets the name pointer to NULL and utf8_width() returns 0. Since name_len does not change, the loop iterates once more and pick_one_utf8_char() dereferences the NULL pointer, crashing. - For control characters, utf8_width() returns -1, so name_len grows when it is expected to shrink. This can cause the loop to consume more characters than the string contains, reading past the trailing NUL. By default, fill_print_name() will C-quote filenames which escapes control characters and invalid bytes to printable text. That avoids this bug from being triggered; however, with core.quotePath=false, most characters are no longer escaped (though some control characters still are) and raw bytes can reach this code. Add tests exercising both failure modes with core.quotePath=false and a narrow --stat-name-width to force truncation: one with a bare 0xC0 byte (invalid UTF-8 lead byte, triggers NULL deref) and one with several C1 control characters (repeats of 0xC2 0x9F, causing the loop to read past the end of the string). The second test reliably catches the out-of-bounds read when run under ASan, though it may pass silently without sanitizers. Fix both issues by introducing utf8_ish_width(), a thin wrapper around utf8_width() that guarantees the pointer always advances and the returned width is never negative: - On invalid UTF-8 it restores the pointer, advances by one byte, and returns width 1 (matching the strlen()-based fallback used by utf8_strwidth()). - On a control character it returns 0 (matching utf8_strnwidth() which skips them). Also add a "&& *name" guard to the while-loop condition so it terminates at end-of-string even when utf8_strwidth()'s strlen() fallback causes name_len to exceed the sum of per-character widths. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-04-07Merge branch 'mm/line-log-use-standard-diff-output'Junio C Hamano1-2/+277
The way the "git log -L<range>:<file>" feature is bolted onto the log/diff machinery is being reworked a bit to make the feature compatible with more diff options, like -S/G. * mm/line-log-use-standard-diff-output: doc: note that -L supports patch formatting and pickaxe options t4211: add tests for -L with standard diff options line-log: route -L output through the standard diff pipeline line-log: fix crash when combined with pickaxe options
2026-03-16line-log: route -L output through the standard diff pipelineMichael Montalbo1-2/+277
`git log -L` has always bypassed the standard diff pipeline. `dump_diff_hacky()` in line-log.c hand-rolls its own diff headers and hunk output, which means most diff formatting options are silently ignored. A NEEDSWORK comment has acknowledged this since the feature was introduced: /* * NEEDSWORK: manually building a diff here is not the Right * Thing(tm). log -L should be built into the diff pipeline. */ Remove `dump_diff_hacky()` and its helpers and route -L output through `builtin_diff()` / `fn_out_consume()`, the same path used by `git diff` and `git log -p`. The mechanism is a pair of callback wrappers that sit between `xdi_diff_outf()` and `fn_out_consume()`, filtering xdiff's output to only the tracked line ranges. To ensure xdiff emits all lines within each range as context, the context length is inflated to span the largest range. Wire up the `-L` implies `--patch` default in revision setup rather than forcing it at output time, so `line_log_print()` is just `diffcore_std()` + `diff_flush()` with no format save/restore. Rename detection is a no-op since pairs are already resolved during the history walk in `queue_diffs()`, but running `diffcore_std()` means `-S`/`-G` (pickaxe), `--orderfile`, and `--diff-filter` now work with `-L`, and `diff_resolve_rename_copy()` sets pair statuses correctly without manual assignment. Switch `diff_filepair_dup()` from `xmalloc` to `xcalloc` so that new fields (including `line_ranges`) are zero-initialized by default. As a result, diff formatting options that were previously silently ignored (e.g. --word-diff, --no-prefix, -w, --color-moved) now work with -L, and output gains `index` lines, `new file mode` headers, and funcname context in `@@` headers. This is a user-visible output change: tools that parse -L output may need to handle the additional header lines. The context-length inflation means xdiff may process more output than needed for very wide line ranges, but benchmarks on files up to 7800 lines show no measurable regression. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-10Merge branch 'mm/diff-no-index-find-object'Junio C Hamano1-0/+2
"git diff --no-index --find-object=<object-name>" outside a repository of course wouldn't be able to find the object and died while parsing the command line, which is made to die in a bit more user-friendly way. * mm/diff-no-index-find-object: diff: fix crash with --find-object outside repository
2026-03-09Merge branch 'lp/diff-stat-utf8-display-width-fix'Junio C Hamano1-8/+4
"git log --graph --stat" did not count the display width of colored graph part of its own output correctly, which has been corrected. * lp/diff-stat-utf8-display-width-fix: t4052: test for diffstat width when prefix contains ANSI escape codes diff: handle ANSI escape codes in prefix when calculating diffstat width
2026-03-04Merge branch 'en/merge-ort-almost-wo-the-repository'Junio C Hamano1-1/+1
Mark the marge-ort codebase to prevent more uses of the_repository from getting added. * en/merge-ort-almost-wo-the-repository: replay: prevent the_repository from coming back merge-ort: prevent the_repository from coming back merge-ort: replace the_hash_algo with opt->repo->hash_algo merge-ort: replace the_repository with opt->repo merge-ort: pass repository to write_tree() merge,diff: remove the_repository check before prefetching blobs
2026-03-02diff: fix crash with --find-object outside repositoryMichael Montalbo1-0/+2
When "git diff --find-object=<oid>" is run outside a git repository, the option parsing callback eagerly resolves the OID via repo_get_oid(), which reaches get_main_ref_store() and hits a BUG() assertion because no repository has been set up. Check startup_info->have_repository before attempting to resolve the OID, and return a user-friendly error instead. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-27Merge branch 'jc/whitespace-incomplete-line'Junio C Hamano1-2/+20
It does not make much sense to apply the "incomplete-line" whitespace rule to symbolic links, whose contents almost always lack the final newline. "git apply" and "git diff" are now taught to exclude them for a change to symbolic links. * jc/whitespace-incomplete-line: whitespace: symbolic links usually lack LF at the end
2026-02-27diff: handle ANSI escape codes in prefix when calculating diffstat widthLorenzoPegorari1-8/+4
The diffstat width is calculated by taking the terminal width and incorrectly subtracting the `strlen()` of `line_prefix`, instead of the actual display width of `line_prefix`, which may contain ANSI escape codes (e.g., ANSI-colored strings in `log --graph --stat`). Utilize the display width instead, obtained via `utf8_strnwidth()` with the flag `skip_ansi`. Signed-off-by: LorenzoPegorari <lorenzo.pegorari2002@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-21merge,diff: remove the_repository check before prefetching blobsElijah Newren1-1/+1
Prefetching of blobs from promisor remotes was added to diff in 7fbbcb21b162 (diff: batch fetching of missing blobs, 2019-04-05). In that commit, https://lore.kernel.org/git/20190405170934.20441-1-jonathantanmy@google.com/ was squashed into https://lore.kernel.org/git/44de02e584f449481e6fb00cf35d74adf0192e9d.1553895166.git.jonathantanmy@google.com/ without the extra explanation about the squashed changes being added to the commit message; in particular, this explanation from that first link is absent: > Also, prefetch only if the repository being diffed is the_repository > (because we do not support lazy fetching for any other repository > anyway). Then, later, this checking was spread from diff.c to diffcore-rename.c and diffcore-break.c by 95acf11a3dc3 (diff: restrict when prefetching occurs, 2020-04-07) and then further split in d331dd3b0c82 (diffcore-rename: allow different missing_object_cb functions, 2021-06-22). I also copied the logic from prefetching blobs from diff.c to merge-ort.c in 2bff554b23e8 (merge-ort: add prefetching for content merges, 2021-06-22). The reason for all these checks was noted above -- we only supported lazy fetching for the_repository. However, that changed with ef830cc43412 (promisor-remote: teach lazy-fetch in any repo, 2021-06-17), so these checks are now unnecessary. Remove them. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-13Merge branch 'cf/c23-const-preserving-strchr-updates-0'Junio C Hamano1-2/+2
ISO C23 redefines strchr and friends that tradiotionally took a const pointer and returned a non-const pointer derived from it to preserve constness (i.e., if you ask for a substring in a const string, you get a const pointer to the substring). Update code paths that used non-const pointer to receive their results that did not have to be non-const to adjust. * cf/c23-const-preserving-strchr-updates-0: gpg-interface: remove an unnecessary NULL initialization global: constify some pointers that are not written to
2026-02-05whitespace: symbolic links usually lack LF at the endJunio C Hamano1-2/+20
For a patch that touches a symbolic link, it is perfectly normal that the contents ends with "\ No newline at end of file". The checks introduced recently to detect incomplete lines (i.e., a text file that lack the newline on its final line) should not trigger. Disable the check early for symbolic links, both in "git apply" and "git diff" and test them. For "git apply", we check only when the postimage is a symbolic link regardless of the preimage, and we only care about preimage when applying in reverse. Similarly, "git diff" would warn only when the postimage is a symbolic link, or the preimage when running "git diff -R". Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-05global: constify some pointers that are not written toCollin Funk1-2/+2
The recent glibc 2.43 release had the following change listed in its NEWS file: For ISO C23, the functions bsearch, memchr, strchr, strpbrk, strrchr, strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr that return pointers into their input arrays now have definitions as macros that return a pointer to a const-qualified type when the input argument is a pointer to a const-qualified type. When compiling with GCC 15, which defaults to -std=gnu23, this causes many warnings like this: merge-ort.c: In function ‘apply_directory_rename_modifications’: merge-ort.c:2734:36: warning: initialization discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] 2734 | char *last_slash = strrchr(cur_path, '/'); | ^~~~~~~ This patch fixes the more obvious ones by making them const when we do not write to the returned pointer. Signed-off-by: Collin Funk <collin.funk1@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-05Merge branch 'lp/diff-stat-utf8-display-width-fix'Junio C Hamano1-11/+6
The computation of column width made by "git diff --stat" was confused when pathnames contain non-ASCII characters. * lp/diff-stat-utf8-display-width-fix: t4073: add test for diffstat paths length when containing UTF-8 chars diff: improve scaling of filenames in diffstat to handle UTF-8 chars
2026-01-16diff: improve scaling of filenames in diffstat to handle UTF-8 charsLorenzoPegorari1-11/+6
The `show_stats()` function tries to scale the filenames in the diffstat to ensure they don't exceed the given `name-width`. It does so by calculating the "display width" of the characters to be dropped, but then advances the filename pointer by that number of bytes. However, the "display width" of a character is not always equal to its byte count. The result is that sometimes, when displaying UTF-8 characters, filenames exceed the given `name-width`, and frequently the bytes of the UTF-8 characters are truncated. The following is an example of the issue, where the 2 files are "HelloHi" and "Hello你好", and `name-width=6`: ...oHi | 0 ...<BD><A0>好 | 0 Make the filename pointer move by the actual number of bytes of the characters to drop from the filename, rather than their display width, using the `utf8_width()` function. Force `len` to not be less than 0 (this happens if the given `name-width` is 2 or less), otherwise an infinite loop is entered. Signed-off-by: LorenzoPegorari <lorenzo.pegorari2002@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-12-30diff: avoid segfault with freed entriesDerrick Stolee1-0/+5
When computing a diff in a partial clone, there is a chance that we could trigger a prefetch of missing objects at the same time as we are freeing entries from the global diff queue. This is difficult to reproduce, as we need to have some objects be freed from the queue before triggering the prefetch of missing objects. There is a new test in t4067 that does trigger the segmentation fault that results in this case. The fix is to set the queue pointer to NULL after it is freed, and then to be careful about NULL values in the prefetch. The more elaborate explanation is that within diffcore_std(), we may skip the initial prefetch due to the output format (--name-only in the test) and go straight to diffcore_skip_stat_unmatch(). In that method, the index entries that have been invalidated by path changes show up as entries but may be deleted because they are not actually content diffs and only newer timestamps than expected. As those entries are deleted, later entries are checked with diff_filespec_check_stat_unmatch(), which uses diff_queued_diff_prefetch() as the missing_object_cb in its diff options. That can trigger downloading missing objects if the appropriate scenario occurs to trigger a call to diff_popoulate_filespec(). It's finally within that callback to diff_queued_diff_prefetch() that the segfault occurs. The test was hard to find because it required some real differences, some not-different files that had a newer modified time, and the order of those files alphabetically was important to trigger the deletion before the prefetch was triggered. I briefly considered a "lock" member for the diff queue, but it was a much larger diff and introduced many more possible error scenarios. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-12-14Merge branch 'rs/diff-index-find-copies-harder-optim'Junio C Hamano1-0/+20
Halve the memory consumed by artificial filepairs created during "git diff --find-copioes-harder", also making the operation run faster. * rs/diff-index-find-copies-harder-optim: diff-index: don't queue unchanged filepairs with diff_change()
2025-11-30Merge branch 'jc/whitespace-incomplete-line'Junio C Hamano1-47/+98
Both "git apply" and "git diff" learn a new whitespace error class, "incomplete-line". * jc/whitespace-incomplete-line: attr: enable incomplete-line whitespace error for this project diff: highlight and error out on incomplete lines apply: check and fix incomplete lines whitespace: allocate a few more bits and define WS_INCOMPLETE_LINE apply: revamp the parsing of incomplete lines diff: update the way rewrite diff handles incomplete lines diff: call emit_callback ecbdata everywhere diff: refactor output of incomplete line diff: keep track of the type of the last line seen diff: correct suppress_blank_empty hack diff: emit_line_ws_markup() if/else style fix whitespace: correct bit assignment comments
2025-11-30diff-index: don't queue unchanged filepairs with diff_change()René Scharfe1-0/+20
diff_cache() queues unchanged filepairs if the flag find_copies_harder is set, and uses diff_change() for that. This function allocates a filespec for each side, does a few other things that are unnecessary for unchanged filepairs and always sets the diff_flag has_changes, which is simply misleading in this case. Add a new streamlined function for queuing unchanged filepairs and use it in show_modified(), which is called by diff_cache() via oneway_diff() and do_oneway_diff(). It allocates only a single filespec for each filepair and uses it twice with reference counting. This has a measurable effect if there are a lot of them, like in the Linux repo: Benchmark 1: ./git_v2.52.0 -C ../linux diff --cached --find-copies-harder Time (mean ± σ): 31.8 ms ± 0.2 ms [User: 24.2 ms, System: 6.3 ms] Range (min … max): 31.5 ms … 32.3 ms 85 runs Benchmark 2: ./git -C ../linux diff --cached --find-copies-harder Time (mean ± σ): 23.9 ms ± 0.2 ms [User: 18.1 ms, System: 4.6 ms] Range (min … max): 23.5 ms … 24.4 ms 111 runs Summary ./git -C ../linux diff --cached --find-copies-harder ran 1.33 ± 0.01 times faster than ./git_v2.52.0 -C ../linux diff --cached --find-copies-harder Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-26Merge branch 'ad/blame-diff-algorithm'Junio C Hamano1-1/+0
"git blame" learns "--diff-algorithm=<algo>" option. * ad/blame-diff-algorithm: blame: make diff algorithm configurable xdiff: add 'minimal' to XDF_DIFF_ALGORITHM_MASK
2025-11-21Merge branch 'rs/diff-quiet-no-rename'Junio C Hamano1-0/+2
As "git diff --quiet" only cares about the existence of any changes, disable rename/copy detection to skip more expensive processing whose result will be discarded anyway. * rs/diff-quiet-no-rename: diff: disable rename detection with --quiet
2025-11-17xdiff: add 'minimal' to XDF_DIFF_ALGORITHM_MASKAntonin Delpeuch1-1/+0
The XDF_DIFF_ALGORITHM_MASK bit mask only includes bits for the patience and histogram diffs, not for the minimal one. This means that when reseting the diff algorithm to the default one, one needs to separately clear the bit for the minimal diff. There are places in the code that fail to do that: merge-ort.c and builtin/merge-file.c. Add the XDF_NEED_MINIMAL bit to the bit mask, and remove the separate clearing of this bit in the places where it hasn't been forgotten. Signed-off-by: Antonin Delpeuch <antonin@delpeuch.eu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: highlight and error out on incomplete linesJunio C Hamano1-2/+27
Teach "git diff" to highlight "\ No newline at end of file" message as a whitespace error when incomplete-line whitespace error class is in effect. Thanks to the previous refactoring of complete rewrite code path, we can do this at a single place. Unlike whitespace errors in the payload where we need to annotate in line, possibly using colors, the line that has whitespace problems, we have a dedicated line already that can serve as the error message, so paint it as a whitespace error message. Also teach "git diff --check" to notice incomplete lines as whitespace errors and report when incomplete-line whitespace error class is in effect. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12whitespace: allocate a few more bits and define WS_INCOMPLETE_LINEJunio C Hamano1-8/+8
Reserve a few more bits in the diff flags word to be used for future whitespace rules. Add WS_INCOMPLETE_LINE without implementing the behaviour (yet). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: update the way rewrite diff handles incomplete linesJunio C Hamano1-15/+22
The diff_symbol based output framework uses one DIFF_SYMBOL_* enum value per the kind of output lines of "git diff", which corresponds to one output line from the xdiff machinery used internally. Most notably, DIFF_SYMBOL_PLUS and DIFF_SYMBOL_MINUS that correspond to "+" and "-" lines are designed to always take a complete line, even if the output from xdiff machinery may produce "\ No newline at the end of file" immediately after them. But this is not true in the rewrite-diff codepath, which completely bypasses the xdiff machinery. Since the code path feeds the bytes directly from the payload to the output routines, the output layer has to deal with an incomplete line with DIFF_SYMBOL_PLUS and DIFF_SYMBOL_MINUS, which never would see an incomplete line in the normal code paths. This lack of final newline is compensated by an ugly hack for a fabricated DIFF_SYMBOL_NO_LF_EOF token to inject an extra newline to the output to simulate output coming from the xdiff machinery. Revamp the way the complete-rewrite code path feeds the lines to the output layer by treating the last line of the pre/post image when it is an incomplete line specially. This lets us remove the DIFF_SYMBOL_NO_LF_EOF hack and use the usual DIFF_SYMBOL_CONTEXT_INCOMPLETE code path, which will later learn how to handle whitespace errors. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: call emit_callback ecbdata everywhereJunio C Hamano1-6/+6
Everybody else, except for emit_rewrite_lines(), calls the emit_callback data ecbdata. Make sure we call the same thing by the same name for consistency. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: refactor output of incomplete lineJunio C Hamano1-2/+12
Create a helper function that reacts to "\ No newline at the end of file" in preparation for unifying the incomplete line handling in the code path that handles xdiff output and the code path that bypasses xdiff and produces a complete-rewrite patch. Currently the output from the DIFF_SYMBOL_CONTEXT_INCOMPLETE case still (ab)uses the same code as what is used for context lines, but that would change in a later step where we introduce support to treat an incomplete line as a whitespace error. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: keep track of the type of the last line seenJunio C Hamano1-0/+11
The "\ No newline at the end of the file" can come after any of the "-" (deleted preimage line), " " (unchanged line), or "+" (added postimage line). In later steps in this series, we will start treating a change that makes a file to end in an incomplete line as a whitespace error, and we would need to know what the previous line was when we react to "\ No newline" in the diff output. If the previous line was a context (i.e., unchanged) line, the file lacked the final newline before the change, and the change did not touch that line and left it still incomplete, so we do not want to warn in such a case. Teach fn_out_consume() function to keep track of what the previous line was, and prepare an otherwise empty switch statement to let us react differently to "\ No newline" based on that. Note that there is an existing curiosity (read: likely to be a bug) in the code that increments line number in the preimage file every time it sees a line with "\ No newline" on it, regardless of what the previous line was. I left it as-is, because it does not affect the main theme of this series, and more importantly, I do not think it matters, as these numbers are used only to compare them with blank_at_eof_in_{pre,post}image to issue a warning when we see more empty line was added at the end, but by definition, after we see "\ No newline at the end of the file" for an added line, we will not see an added line for the file. An independent audit to ensure that this curious increment can be safely removed would make a good #leftoverbits clean-up (we may even find some code that decrements this counter or over-increments the other quantity this counter is compared with that compensates the effect of this curious increment that hides a bug, in which case we may also need to remove them). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: correct suppress_blank_empty hackJunio C Hamano1-16/+11
The suppress-blank-empty feature abused the CONTEXT_INCOMPLETE symbol that was meant to be used only for "\ No newline at the end of file" code path. The intent of the feature was to turn a context line we receive from xdiff machinery (which always uses ' ' for context lines, even an empty one) and spit it out as a truly empty line. Perform such a conversion very locally at where a line from xdiff that begins with ' ' is handled for output; there are many checks before the control reaches such place that checks the first letter of the diff output line to see if it is a context line, and having to check for '\n' and treat it as a special case is error prone. In order to catch similar hacks in the future, make sure the code path that is meant for "\ No newline" case checks the first byte is indeed a backslash. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12diff: emit_line_ws_markup() if/else style fixJunio C Hamano1-4/+4
Apply the simple rule: if you need {} in one arm of the if/else if/else... cascade, have {} in all of them. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12whitespace: correct bit assignment commentsJunio C Hamano1-2/+5
A comment in diff.c claimed that bits up to 12th (counting from 0th) are whitespace rules, and 13th thru 15th are for new/old/context, but it turns out it was miscounting. Correct them, and clarify where the whitespace rule bits come from in the comment. Extend bit assignment comments to cover bits used for color-moved, which weren't described. Also update the way these bit constants are defined to use (1 << N) notation, instead of octal constants, as it tends to make it easier to notice a breakage like this. Sprinkle a few blank lines between logically distinct groups of CPP macro definitions to make them easier to read. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-10diff: disable rename detection with --quietRené Scharfe1-0/+2
Detecting renames and copies improves diff's output. This effort is wasted if we don't show any. Disable detection in that case. This actually fixes the error code when using the options --cached, --find-copies-harder, --no-ext-diff and --quiet together: run_diff_index() indirectly calls diff-lib.c::show_modified(), which queues even non-modified entries using diff_change() because we need them for copy detection. diff_change() sets flags.has_changes, though, which causes diff_can_quit_early() to declare we're done after seeing only the very first entry -- way too soon. Using --cached, --find-copies-harder and --quiet together without --no-ext-diff was not affected even before, as it causes the flag flags.diff_from_contents to be set, which disables the optimization in a different way. Reported-by: D. Ben Knoble <ben.knoble@gmail.com> Suggested-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-24diff: simplify run_external_diff() quiet logicJeff King1-3/+2
We'd sometimes end up in run_external_diff() to do a dry-run diff (e.g., to find content-level changes for --quiet). We recognize this quiet mode by seeing the lack of DIFF_FORMAT_PATCH in the output format. But since introducing an explicit dry-run check via 3ed5d8bd73 (diff: stop output garbled message in dry run mode, 2025-10-20), this logic can never trigger. We can only get to this function by calling diff_flush_patch(), and that comes from only two places: 1. A dry-run flush comes from diff_flush_patch_quietly(), which is always in dry-run mode (so the other half of our "||" is true anyway). 2. A regular flush comes from diff_flush_patch_all_file_pairs(), which is only called when output_format has DIFF_FORMAT_PATCH in it. So we can simplify our "quiet" condition to just checking dry-run mode (which used to be a specific flag, but recently became just a NULL "file" pointer). And since it's so simple, we can just do that inline. This makes the logic about o->file more obvious, since we handle the NULL and non-stdout cases next to each other. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-24diff: drop dry-run redirection to /dev/nullJeff King1-28/+3
As an added protection against dry-run diffs accidentally producing output, we redirect diff_options.file to /dev/null. But as of the previous patch, this now does nothing, since dry-run diffs are implemented by setting "file" to NULL. So we can drop this extra code with no change in behavior. This is effectively a revert of 623f7af284 (diff: restore redirection to /dev/null for diff_from_contents, 2025-10-17) and 3da4413dbc (diff: make sure the other caller of diff_flush_patch_quietly() is silent, 2025-10-22), but: 1. We get a conflict because we already dropped the color_moved handling in an earlier patch. But we just resolve the conflicts to "theirs" (removing all of the code). 2. We retain the test from 623f7af284. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>