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1569 commits

Author SHA1 Message Date
Junio C Hamano 6047b28eb7 Merge branch 'en/header-split-cleanup'
Split key function and data structure definitions out of cache.h to
new header files and adjust the users.

* en/header-split-cleanup:
  csum-file.h: remove unnecessary inclusion of cache.h
  write-or-die.h: move declarations for write-or-die.c functions from cache.h
  treewide: remove cache.h inclusion due to setup.h changes
  setup.h: move declarations for setup.c functions from cache.h
  treewide: remove cache.h inclusion due to environment.h changes
  environment.h: move declarations for environment.c functions from cache.h
  treewide: remove unnecessary includes of cache.h
  wrapper.h: move declarations for wrapper.c functions from cache.h
  path.h: move function declarations for path.c functions from cache.h
  cache.h: remove expand_user_path()
  abspath.h: move absolute path functions from cache.h
  environment: move comment_line_char from cache.h
  treewide: remove unnecessary cache.h inclusion from several sources
  treewide: remove unnecessary inclusion of gettext.h
  treewide: be explicit about dependence on gettext.h
  treewide: remove unnecessary cache.h inclusion from a few headers
2023-04-06 13:38:31 -07:00
Junio C Hamano 72871b198f Merge branch 'ab/remove-implicit-use-of-the-repository'
Code clean-up around the use of the_repository.

* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-06 13:38:30 -07:00
Junio C Hamano e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason a5183d7696 cocci: apply the "promisor-remote.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"promisor-remote.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:46 -07:00
Ævar Arnfjörð Bjarmason d850b7a545 cocci: apply the "cache.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"cache.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:36 -07:00
Junio C Hamano 15108de2fa Merge branch 'jk/format-patch-ignore-noprefix'
"git format-patch" honors the src/dst prefixes set to nonstandard
values with configuration variables like "diff.noprefix", causing
receiving end of the patch that expects the standard -p1 format to
break.  Teach "format-patch" to ignore end-user configuration and
always use the standard prefixes.

This is a backward compatibility breaking change.

* jk/format-patch-ignore-noprefix:
  rebase: prefer --default-prefix to --{src,dst}-prefix for format-patch
  format-patch: add format.noprefix option
  format-patch: do not respect diff.noprefix
  diff: add --default-prefix option
  t4013: add tests for diff prefix options
  diff: factor out src/dst prefix setup
2023-03-21 14:18:55 -07:00
Elijah Newren e38da487cc setup.h: move declarations for setup.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren 32a8f51061 environment.h: move declarations for environment.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren d5ebb50dcb wrapper.h: move declarations for wrapper.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren 0b027f6ca7 abspath.h: move absolute path functions from cache.h
This is another step towards letting us remove the include of cache.h in
strbuf.c.  It does mean that we also need to add includes of abspath.h
in a number of C files.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Junio C Hamano 88cc8ed8bc Merge branch 'en/header-cleanup'
Code clean-up to clarify the rule that "git-compat-util.h" must be
the first to be included.

* en/header-cleanup:
  diff.h: remove unnecessary include of object.h
  Remove unnecessary includes of builtin.h
  treewide: replace cache.h with more direct headers, where possible
  replace-object.h: move read_replace_refs declaration from cache.h to here
  object-store.h: move struct object_info from cache.h
  dir.h: refactor to no longer need to include cache.h
  object.h: stop depending on cache.h; make cache.h depend on object.h
  ident.h: move ident-related declarations out of cache.h
  pretty.h: move has_non_ascii() declaration from commit.h
  cache.h: remove dependence on hex.h; make other files include it explicitly
  hex.h: move some hex-related declarations from cache.h
  hash.h: move some oid-related declarations from cache.h
  alloc.h: move ALLOC_GROW() functions from cache.h
  treewide: remove unnecessary cache.h includes in source files
  treewide: remove unnecessary cache.h includes
  treewide: remove unnecessary git-compat-util.h includes in headers
  treewide: ensure one of the appropriate headers is sourced first
2023-03-17 14:03:09 -07:00
Jeff King b39a569729 diff: add --default-prefix option
You can change the output of prefixes with diff.noprefix and
diff.mnemonicprefix, but there's no easy way to override them from the
command-line. We do have "--no-prefix", but there's no way to get back
to the default prefix. So let's add an option to do that.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-09 08:32:21 -08:00
Jeff King 6799aadfdf diff: factor out src/dst prefix setup
We directly manipulate diffopt's a_prefix and b_prefix to set up either
the default "a/foo" prefix or the "--no-prefix" variant. Although this
is only a few lines, it's worth pulling these into their own functions.
That lets us avoid one repetition already in this patch, but will also
give us a cleaner interface for callers which want to tweak this
setting.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-09 08:32:17 -08:00
Junio C Hamano ece8dc97ae Merge branch 'jc/diff-algo-attribute'
The "diff" drivers specified by the "diff" attribute attached to
paths can now specify which algorithm (e.g. histogram) to use.

* jc/diff-algo-attribute:
  diff: teach diff to read algorithm from diff driver
  diff: consolidate diff algorithm option parsing
2023-02-27 10:08:56 -08:00
Elijah Newren 41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Elijah Newren 36bf195890 alloc.h: move ALLOC_GROW() functions from cache.h
This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places.  It does mean that we also need to add
includes of alloc.h in a number of C files.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:28 -08:00
John Cai a4cf900ee7 diff: teach diff to read algorithm from diff driver
It can be useful to specify diff algorithms per file type. For example,
one may want to use the minimal diff algorithm for .json files, another
for .c files, etc.

The diff machinery already checks attributes for a diff driver. Teach
the diff driver parser a new type "algorithm" to look for in the
config, which will be used if a driver has been specified through the
attributes.

Enforce precedence of the diff algorithm by favoring the command line
option, then looking at the driver attributes & config combination, then
finally the diff.algorithm config.

To enforce precedence order, use a new `ignore_driver_algorithm` member
during options parsing to indicate the diff algorithm was set via command
line args.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-21 09:29:10 -08:00
John Cai 11e95e16e8 diff: consolidate diff algorithm option parsing
A subsequent commit will need the ability to tell if the diff algorithm
was set through the command line through setting a new member of
diff_options. While this logic can be added to the
diff_opt_diff_algorithm() callback, the `--minimal` and `--histogram`
options are handled via OPT_BIT without a callback.

Remedy this by consolidating the options parsing logic for --minimal and
--histogram into one callback. This way we can modify `diff_options` in
that function.

As an additional refactor, the logic that sets the diff algorithm in
diff_opt_diff_algorithm() can be refactored into a helper that will
allow multiple callsites to set the diff algorithm.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-21 09:29:08 -08:00
Junio C Hamano 1120c54c12 Merge branch 'jk/ext-diff-with-relative'
"git diff --relative" did not mix well with "git diff --ext-diff",
which has been corrected.

* jk/ext-diff-with-relative:
  diff: drop "name" parameter from prepare_temp_file()
  diff: clean up external-diff argv setup
  diff: use filespec path to set up tempfiles for ext-diff
2023-01-16 12:07:46 -08:00
Jeff King f034bb1cad diff: drop "name" parameter from prepare_temp_file()
The prepare_temp_file() function takes a diff_filespec as well as a
filename. But it is almost certainly an error to pass in a name that
isn't the filespec's "path" parameter, since that is the only thing that
reliably tells us how to find the content (and indeed, this was the
source of a recently-fixed bug).

So let's drop the redundant "name" parameter and just use one->path
throughout the function. This simplifies the interface a little bit, and
makes it impossible for calling code to get it wrong.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-06 21:50:09 +09:00
Jeff King de8f14e1c0 diff: clean up external-diff argv setup
Since the previous commit, setting up the tempfile for an external diff
uses df->path from the diff_filespec, rather than the logical name. This
means add_external_diff_name() does not need to take a "name" parameter
at all, and we can drop it. And that in turn lets us simplify the
conditional for handling renames (when the "other" name is non-NULL).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-06 21:50:07 +09:00
Jeff King a0f83e7776 diff: use filespec path to set up tempfiles for ext-diff
When we're going to run an external diff, we have to make the contents
of the pre- and post-images available either by dumping them to a
tempfile, or by pointing at a valid file in the worktree. The logic of
this is all handled by prepare_temp_file(), and we just pass in the
filename and the diff_filespec.

But there's a gotcha here. The "filename" we have is a logical filename
and not necessarily a path on disk or in the repository. This matters in
at least one case: when using "--relative", we may have a name like
"foo", even though the file content is found at "subdir/foo". As a
result, we look for the wrong path, fail to find "foo", and claim that
the file has been deleted (passing "/dev/null" to the external diff,
rather than the correct worktree path).

We can fix this by passing the pathname from the diff_filespec, which
should always be a full repository path (and that's what we want even if
reusing a worktree file, since we're always operating from the top-level
of the working tree).

The breakage seems to go all the way back to cd676a5136 (diff
--relative: output paths as relative to the current subdirectory,
2008-02-12). As far as I can tell, before then "name" would always have
been the same as the filespec's "path".

There are two related cases I looked at that aren't buggy:

  1. the only other caller of prepare_temp_file() is run_textconv(). But
     it always passes the filespec's path field, so it's OK.

  2. I wondered if file renames/copies might cause similar confusion.
     But they don't, because run_external_diff() receives two names in
     that case: "name" and "other", which correspond to the two sides of
     the diff. And we did correctly pass "other" when handling the
     post-image side. Barring the use of "--relative", that would always
     match "two->path", the path of the second filespec (and the rename
     destination).

So the only bug is just the interaction with external diff drivers and
--relative.

Reported-by: Carl Baldwin <carl@ecbaldwin.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-06 21:49:55 +09:00
Junio C Hamano e57caee004 Merge branch 'pg/diff-stat-unmerged-regression-fix'
The output from "git diff --stat" on an unmerged path lost the
terminating LF in Git 2.39, which has been corrected.

* pg/diff-stat-unmerged-regression-fix:
  diff: fix regression with --stat and unmerged file
2022-12-26 11:42:07 +09:00
Junio C Hamano 179547932f Merge branch 'jk/unused-post-2.39'
Code clean-up around unused function parameters.

* jk/unused-post-2.39:
  userdiff: mark unused parameter in internal callback
  list-objects-filter: mark unused parameters in virtual functions
  diff: mark unused parameters in callbacks
  xdiff: mark unused parameter in xdl_call_hunk_func()
  xdiff: drop unused parameter in def_ff()
  ws: drop unused parameter from ws_blank_line()
  list-objects: drop process_gitlink() function
  blob: drop unused parts of parse_blob_buffer()
  ls-refs: use repository parameter to iterate refs
2022-12-26 11:42:05 +09:00
Junio C Hamano ab91f6b7c4 Merge branch 'rs/diff-parseopts'
The way the diff machinery prepares the options array for the
parse_options API has been refactored to avoid resource leaks.

* rs/diff-parseopts:
  diff: remove parseopts member from struct diff_options
  diff: use add_diff_options() in diff_opt_parse()
  diff: factor out add_diff_options()
2022-12-19 11:46:17 +09:00
Peter Grayson 209d9cb011 diff: fix regression with --stat and unmerged file
A regression was introduced in

  12fc4ad89e (diff.c: use utf8_strwidth() to count display width, 2022-09-14)

that causes missing newlines after "Unmerged" entries in `git diff
--cached --stat` output.

This problem affects v2.39.0-rc0 through v2.39.0.

Add the missing newline along with a new test to cover this
behavior.

Signed-off-by: Peter Grayson <pete@jpgrayson.net>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-15 09:12:04 +09:00
Jeff King 61bdc7c5d8 diff: mark unused parameters in callbacks
The diff code provides a format_callback interface, but not every
callback needs each parameter (e.g., the "opt" and "data" parameters are
frequently left unused). Likewise for the output_prefix callback, the
low-level change/add_remove interfaces, the callbacks used by
xdi_diff(), etc.

Mark unused arguments in the callback implementations to quiet
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-13 22:16:23 +09:00
Jeff King c5224f0f4c ws: drop unused parameter from ws_blank_line()
We take a ws_rule parameter, but have never looked at it since the
function was added in 877f23ccb8 (Teach "diff --check" about new blank
lines at end, 2008-06-26). A comment in the function does mention how we
_could_ use it, but nobody has felt the need to do so for over a decade.

We could keep it around as reminder of what could be done, but the
comment serves that purpose. And in the meantime, it triggers
-Wunused-parameter.

So let's drop it, which in turn allows us to drop similar arguments
further up the callstack. I've left the comment intact. It does still
say "ws_rule", but that name is used consistently in the whitespace
code, so the meaning is clear.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-13 22:16:23 +09:00
René Scharfe 189e97bc4b diff: remove parseopts member from struct diff_options
repo_diff_setup() builds the struct option array with git diff's command
line options and stores a pointer to it in the parseopts member of
struct diff_options.  The array is freed by diff_setup_done(), but not
by release_revisions().  Thus calling only repo_diff_setup() and
release_revisions() leaks that array.

We could free it in release_revisions() as well to plug that leak, but
there is a better way: Only build it when needed.  Absorb
prep_parse_options() into the last place that uses the parseopts member
of struct diff_options, add_diff_parseopts(), and get rid of said
member.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-02 08:25:30 +09:00
René Scharfe 6c6048fa7f diff: use add_diff_options() in diff_opt_parse()
Prepare the removal of the parseopts member of struct diff_options by
using the API function add_diff_options() instead of accessing it
directly to get the command line option definitions.  Building the copy
by concatenating with an empty option array is slightly awkward, but
simpler than a non-concat version of add_diff_options() would be to use
in places that need concatenation.

Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-02 08:25:29 +09:00
René Scharfe c5630c4868 diff: factor out add_diff_options()
Add a function for appending the parseopts member of struct diff_options
to a struct option array.  Use it in two sites instead of accessing the
parseopts member directly.  Decoupling callers from diff internals like
that allows us to change the latter.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-02 08:25:29 +09:00
Junio C Hamano 613999cc5c Merge branch 'sg/plug-line-log-leaks'
A handful of leaks in the line-log machinery have been plugged.

* sg/plug-line-log-leaks:
  diff.c: use diff_free_queue()
  line-log: free the diff queues' arrays when processing merge commits
  line-log: free diff queue when processing non-merge commits
2022-11-28 12:13:46 +09:00
Taylor Blau be4ac3b197 Merge branch 'rs/no-more-run-command-v'
Simplify the run-command API.

* rs/no-more-run-command-v:
  replace and remove run_command_v_opt()
  replace and remove run_command_v_opt_cd_env_tr2()
  replace and remove run_command_v_opt_tr2()
  replace and remove run_command_v_opt_cd_env()
  use child_process members "args" and "env" directly
  use child_process member "args" instead of string array variable
  sequencer: simplify building argument list in do_exec()
  bisect--helper: factor out do_bisect_run()
  bisect: simplify building "checkout" argument list
  am: simplify building "show" argument list
  run-command: fix return value comment
  merge: remove always-the-same "verbose" arguments
2022-11-08 17:15:12 -05:00
SZEDER Gábor 586d8b5052 diff.c: use diff_free_queue()
Use diff_free_queue() instead of open-coding it.  This shortens the
code and make it less repetitive.

Note that the second hunk in diff_flush() is interesting, because the
'free_queue' label separates the loop freeing the queue's filepairs
from free()-ing the queue's internal array.  This is somewhat
suspicious, but it was not an issue before: there is only one place
from where we jump to this label with a goto, and that is protected by
an 'if (!q->nr && ...)' condition, i.e. we only skipped the loop
freeing the filepairs when there were no filepairs in the queue to
begin with.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-02 20:16:34 -04:00
SZEDER Gábor 04ae00062d line-log: free diff queue when processing non-merge commits
When processing a non-merge commit, the line-level log first asks the
tree-diff machinery whether any of the files in the given line ranges
were modified between the current commit and its parent, and if some
of them were, then it loads the contents of those files from both
commits to see whether their line ranges were modified and/or need to
be adjusted.  Alas, it doesn't free() the diff queue holding the
results of that query and the contents of those files once its done.
This can add up to a substantial amount of leaked memory, especially
when the file in question is big and is frequently modified: a user
reported "Out of memory, malloc failed" errors with a 2MB text file
that was modified ~2800 times [1] (I estimate the leak would use up
almost 11GB memory in that case).

Free that diff queue to plug this memory leak.  However, instead of
simply open-coding the necessary three lines, add them as a helper
function to the diff API, because it will be useful elsewhere as well.

[1] https://public-inbox.org/git/CAFOPqVXz2XwzX8vGU7wLuqb2ZuwTuOFAzBLRM_QPk+NJa=eC-g@mail.gmail.com/

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-02 20:16:34 -04:00
Taylor Blau 160314e625 Merge branch 'jz/patch-id'
A new "--include-whitespace" option is added to "git patch-id", and
existing bugs in the internal patch-id logic that did not match
what "git patch-id" produces have been corrected.

* jz/patch-id:
  builtin: patch-id: remove unused diff-tree prefix
  builtin: patch-id: add --verbatim as a command mode
  patch-id: fix patch-id for mode changes
  builtin: patch-id: fix patch-id with binary diffs
  patch-id: use stable patch-id for rebases
  patch-id: fix stable patch id for binary / header-only
2022-10-30 21:04:41 -04:00
René Scharfe 0e90673957 use child_process members "args" and "env" directly
Build argument list and environment of child processes by using
struct child_process and populating its members "args" and "env"
directly instead of maintaining separate strvecs and letting
run_command_v_opt() and friends populate these members.  This is
simpler, shorter and slightly more efficient.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-30 14:04:40 -04:00
Junio C Hamano 7d5a4d86a6 Merge branch 'tb/diffstat-with-utf8-strwidth'
"git diff --stat" etc. were invented back when everything was ASCII
and strlen() was a way to measure the display width of a string;
adjust them to compute the display width assuming UTF-8 pathnames.

* tb/diffstat-with-utf8-strwidth:
  diff: leave NEEDWORK notes in show_stats() function
  diff.c: use utf8_strwidth() to count display width
2022-10-28 11:26:55 -07:00
Jerry Zhang 93105aba6c patch-id: fix patch-id for mode changes
Currently patch-id as used in rebase and cherry-pick does not account
for file modes if the file is modified. One consequence of this is
that if you have a local patch that changes modes, but upstream
has applied an outdated version of the patch that doesn't include
that mode change, "git rebase" will drop your local version of the
patch along with your mode changes. It also means that internal
patch-id doesn't produce the same output as the builtin, which does
account for mode changes due to them being part of diff output.

Fix by adding mode to the patch-id if it has changed, in the same
format that would be produced by diff, so that it is compatible
with builtin patch-id.

Signed-off-by: Jerry Zhang <Jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-24 15:44:20 -07:00
Jerry Zhang 51276c1832 patch-id: use stable patch-id for rebases
Git doesn't persist patch-ids during the rebase process, so there is
no need to specifically invoke the unstable variant. Use the stable
logic for all internal patch-id calculations to minimize the number of
code paths and improve test coverage.

Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-24 15:44:19 -07:00
Jerry Zhang 0570be79ea patch-id: fix stable patch id for binary / header-only
Patch-ids for binary patches are found by hashing the object
ids of the before and after objects in succession. However in
the --stable case, there is a bug where hunks are not flushed
for binary and header-only patch ids, which would always result
in a patch-id of 0000. The --unstable case is currently correct.

Reorder the logic to branch into 3 cases for populating the
patch body: header-only which populates nothing, binary which
populates the object ids, and normal which populates the text
diff. All branches will end up flushing the hunk.

Don't populate the ---a/ and +++b/ lines for binary diffs, to correspond
to those lines not being present in the "git diff" text output.
This is necessary because we advertise that the patch-id calculated
internally and used in format-patch is the same that what the
builtin "git patch-id" would produce when piped from a diff.

Update the test to run on both binary and normal files.

Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-24 15:44:19 -07:00
Junio C Hamano ce8529b2bb diff: leave NEEDWORK notes in show_stats() function
The previous step made an attempt to correctly compute display
columns allocated and padded different parts of diffstat output.
There are at least two known codepaths in the function that still
mixes up display widths and byte length that need to be fixed.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-21 15:02:31 -07:00
Jeff King 0e5a87e042 diffstat_consume(): assert non-zero length
The callback interface for xdiff_emit_line_fn gives us a line/len pair,
but diffstat_consume() never looks at "len". At first glance this seems
like a bug that could cause us to read further than xdiff intends. But
in practice, we read only the first character, and xdiff would never
pass us an empty line.

Let's add a run-time assertion that this is true, which clarifies our
assumption and silences -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-17 21:24:03 -07:00
Junio C Hamano d878d83ff0 Merge branch 'en/remerge-diff-fixes'
Fix a few "git log --remerge-diff" bugs.

* en/remerge-diff-fixes:
  diff: fix filtering of merge commits under --remerge-diff
  diff: fix filtering of additional headers under --remerge-diff
  diff: have submodule_format logic avoid additional diff headers
2022-09-15 16:09:46 -07:00
Torsten Bögershausen 12fc4ad89e diff.c: use utf8_strwidth() to count display width
When unicode filenames (encoded in UTF-8) are used, the visible width
on the screen is not the same as strlen().

For example, `git log --stat` may produce an output like this:

[snip the header]

 Arger.txt  | 1 +
 Ärger.txt | 1 +
 2 files changed, 2 insertions(+)

A side note: the original report was about cyrillic filenames.
After some investigations it turned out that
a) This is not a problem with "ambiguous characters" in unicode
b) The same problem exists for all unicode code points (so we
  can use Latin based Umlauts for demonstrations below)

The 'Ä' takes the same space on the screen as the 'A'.
But needs one more byte in memory, so the the `git log --stat` output
for "Arger.txt" (!) gets mis-aligned:
The maximum length is derived from "Ärger.txt", 10 bytes in memory,
9 positions on the screen. That is why "Arger.txt" gets one extra ' '
for aligment, it needs 9 bytes in memory.
If there was a file "Ö", it would be correctly aligned by chance,
but "Öhö" would not.

The solution is of course, to use utf8_strwidth() instead of strlen()
when dealing with the width on screen.

And then there is another problem, code like this:
strbuf_addf(&out, "%-*s", len, name);
(or using the underlying snprintf() function) does not align the
buffer to a minimum of len measured in screen-width, but uses the
memory count.

One could be tempted to wish that snprintf() was UTF-8 aware.
That doesn't seem to be the case anywhere (tested on Linux and Mac),
probably snprintf() uses the "bytes in memory"/strlen() approach to be
compatible with older versions and this will never change.

The basic idea is to change code in diff.c like this
strbuf_addf(&out, "%-*s", len, name);

into something like this:
int padding = len - utf8_strwidth(name);
if (padding < 0)
	padding = 0;
strbuf_addf(&out, " %s%*s", name, padding, "");

The real change is slighty bigger, as it, as well, integrates two calls
of strbuf_addf() into one.

Tests:
Two things need to be tested:
 - The calculation of the maximum width
 - The calculation of padding

The name "textfile" is changed into "tëxtfilë", both have a width of 8.
If strlen() was used, to get the maximum width, the shorter "binfile" would
have been mis-aligned:
 binfile    | [snip]
 tëxtfilë | [snip]

If only "binfile" would be renamed into "binfilë":
 binfilë | [snip]
 textfile | [snip]

In order to verify that the width is calculated correctly everywhere,
"binfile" is renamed into "binfilë", giving 1 bytes more in strlen()
"tëxtfile" is renamed into "tëxtfilë", 2 byte more in strlen().

The updated t4012-diff-binary.sh checks the correct aligment:
 binfilë  | [snip]
 tëxtfilë | [snip]

Reported-by: Alexander Meshcheryakov <alexander.s.m@gmail.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-14 13:48:18 -07:00
Junio C Hamano dd407f1c7c Merge branch 'ab/unused-annotation'
Undoes 'jk/unused-annotation' topic and redoes it to work around
Coccinelle rules misfiring false positives in unrelated codepaths.

* ab/unused-annotation:
  git-compat-util.h: use "deprecated" for UNUSED variables
  git-compat-util.h: use "UNUSED", not "UNUSED(var)"
2022-09-14 12:56:39 -07:00
Junio C Hamano a6b42ec0c6 Merge branch 'jk/unused-annotation'
Annotate function parameters that are not used (but cannot be
removed for structural reasons), to prepare us to later compile
with -Wunused warning turned on.

* jk/unused-annotation:
  is_path_owned_by_current_uid(): mark "report" parameter as unused
  run-command: mark unused async callback parameters
  mark unused read_tree_recursive() callback parameters
  hashmap: mark unused callback parameters
  config: mark unused callback parameters
  streaming: mark unused virtual method parameters
  transport: mark bundle transport_options as unused
  refs: mark unused virtual method parameters
  refs: mark unused reflog callback parameters
  refs: mark unused each_ref_fn parameters
  git-compat-util: add UNUSED macro
2022-09-14 12:56:39 -07:00
Elijah Newren 67360b75c6 diff: fix filtering of merge commits under --remerge-diff
Commit 95433eeed9 ("diff: add ability to insert additional headers for
paths", 2022-02-02) introduced the possibility of additional headers.
Because there could be conflicts with no content differences (e.g. a
modify/delete conflict resolved in favor of taking the modified file
as-is), that commit also modified the diff_queue_is_empty() and
diff_flush_patch() logic to ensure these headers were included even if
there was no associated content diff.

However, the added logic was a bit inconsistent between these two
functions.  diff_queue_is_empty() overlooked the fact that the
additional headers strmap could be non-NULL and empty, which would cause
it to display commits that should have been filtered out.

Fix the diff_queue_is_empty() logic to also account for
additional_path_headers being empty.

Reported-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 09:22:25 -07:00
Elijah Newren 71a146dc70 diff: fix filtering of additional headers under --remerge-diff
Commit 95433eeed9 ("diff: add ability to insert additional headers for
paths", 2022-02-02) introduced the possibility of additional headers.
Because there could be conflicts with no content differences (e.g. a
modify/delete conflict resolved in favor of taking the modified file
as-is), that commit also modified the diff_queue_is_empty() and
diff_flush_patch() logic to ensure these headers were included even if
there was no associated content diff.

However, when the pickaxe is active, we really only want the remerge
conflict headers to be shown when there is an associated content diff.
Adjust the logic in these two functions accordingly.

This also removes the TEST_PASSES_SANITIZE_LEAK=true declaration from
t4069, as there is apparently some kind of memory leak with the pickaxe
code.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 09:22:25 -07:00
Elijah Newren 9b08091cb7 diff: have submodule_format logic avoid additional diff headers
Commit 95433eeed9 ("diff: add ability to insert additional headers for
paths", 2022-02-02) introduced the possibility of additional headers,
created in create_filepairs_for_header_only_notifications().  These are
represented by inserting additional pairs in diff_queued_diff which
always have a mode of 0 and a null_oid.  When these were added, one
code path was noted to assume that at least one of the diff_filespecs
in the pair were valid, and that codepath was corrected.

The submodule_format handling is another codepath with the same issue;
it would operate on these additional headers and attempt to display them
as submodule changes.  Prevent that by explicitly checking for "phoney"
filepairs (i.e. filepairs with both modes being 0).

Reported-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 09:22:25 -07:00
Ævar Arnfjörð Bjarmason 5cf88fd8b0 git-compat-util.h: use "UNUSED", not "UNUSED(var)"
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75d (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-01 10:49:48 -07:00
Jeff King 02c3c59e62 hashmap: mark unused callback parameters
Hashmap comparison functions must conform to a particular callback
interface, but many don't use all of their parameters. Especially the
void cmp_data pointer, but some do not use keydata either (because they
can easily form a full struct to pass when doing lookups). Let's mark
these to make -Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:55 -07:00
Jeff King 783a86c142 config: mark unused callback parameters
The callback passed to git_config() must conform to a particular
interface. But most callbacks don't actually look at the extra "void
*data" parameter. Let's mark the unused parameters to make
-Wunused-parameter happy.

Note there's one unusual case here in get_remote_default() where we
actually ignore the "value" parameter. That's because it's only checking
whether the option is found at all, and not parsing its value.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:55 -07:00
SZEDER Gábor 99d86d60e5 parse-options: PARSE_OPT_KEEP_UNKNOWN only applies to --options
The description of 'PARSE_OPT_KEEP_UNKNOWN' starts with "Keep unknown
arguments instead of erroring out".  This is a bit misleading, as this
flag only applies to unknown --options, while non-option arguments are
kept even without this flag.

Update the description to clarify this, and rename the flag to
PARSE_OPTIONS_KEEP_UNKNOWN_OPT to make this obvious just by looking at
the flag name.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 11:13:14 -07:00
Junio C Hamano 7f8d098b1b Merge branch 'ab/cocci-unused'
Add Coccinelle rules to detect the pattern of initializing and then
finalizing a structure without using it in between at all, which
happens after code restructuring and the compilers fail to
recognize as an unused variable.

* ab/cocci-unused:
  cocci: generalize "unused" rule to cover more than "strbuf"
  cocci: add and apply a rule to find "unused" strbufs
  cocci: have "coccicheck{,-pending}" depend on "coccicheck-test"
  cocci: add a "coccicheck-test" target and test *.cocci rules
  Makefile & .gitignore: ignore & clean "git.res", not "*.res"
  Makefile: remove mandatory "spatch" arguments from SPATCH_FLAGS
2022-07-18 13:31:57 -07:00
Ævar Arnfjörð Bjarmason 4f40f6cb73 cocci: add and apply a rule to find "unused" strbufs
Add a coccinelle rule to remove "struct strbuf" initialization
followed by calling "strbuf_release()" function, without any uses of
the strbuf in the same function.

See the tests in contrib/coccinelle/tests/unused.{c,res} for what it's
intended to find and replace.

The inclusion of "contrib/scalar/scalar.c" is because "spatch" was
manually run on it (we don't usually run spatch on contrib).

Per the "buggy code" comment we also match a strbuf_init() before the
xmalloc(), but we're not seeking to be so strict as to make checks
that the compiler will catch for us redundant. Saying we'll match
either "init" or "xmalloc" lines makes the rule simpler.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06 12:24:43 -07:00
Johannes Schindelin 2715e8a931 merge-ort: make path_messages a strmap to a string_list
This allows us once again to get away with less data copying.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
René Scharfe 8af759374e diff: use mks_tempfile_dt()
Git uses temporary files to pass the contents of blobs to external diff
programs and textconv filters.  It calls mks_tempfile_ts() to create
them, which puts them all in the same directory.  This requires adding
a random name prefix.

Use mks_tempfile_dt() instead, which allows the files to have arbitrary
names, each in their own separate temporary directory.  This way they
can have the same basename as the original blob, which looks nicer in
graphical diff programs.

The test in t4020 to check the prettiness of the temporary paths was
neutered by 5476bdf0e8 (diff tests: don't ignore "git diff" exit code in
"read" loop, 2022-03-07), which removed its grep check without replacing
it with an equivalent test_cmp check.  Add one that only checks the
basename of the temporary file and nothing else.

And make the test more robust while at it, by using test_when_finished
to get rid of the added file even if the test fails.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-20 16:17:35 -07:00
Junio C Hamano 361c2566c0 Merge branch 'ab/plug-random-leaks'
Double-free fix for a recently merged topic.

* ab/plug-random-leaks:
  diff.c: fix a double-free regression in a18d66cefb
  tests: demonstrate "show --word-diff --color-moved" regression
2022-03-23 14:09:31 -07:00
Ævar Arnfjörð Bjarmason 77e56d55ba diff.c: fix a double-free regression in a18d66cefb
My a18d66cefb (diff.c: free "buf" in diff_words_flush(), 2022-03-04)
has what it retrospect is a rather obvious bug (I don't know what I
was thinking, if it all): We use the "emitted_symbols" allocation in
append_emitted_diff_symbol() N times, but starting with a18d66cefb
we'd free it after its first use!

The correct way to free this data would have been to add the free() to
the existing free_diff_words_data() function, so let's do that. The
"ecbdata->diff_words->opt->emitted_symbols" might be NULL, so let's
add a trivial free_emitted_diff_symbols() helper next to the function
that appends to it.

This fixes the "no effect on show from" leak tested for in the
preceding commit. Perhaps confusingly this change will skip that test
under SANITIZE=leak, but otherwise opt-in the
"t4015-diff-whitespace.sh" test.

The reason is that a18d66cefb "fixed" the leak in the preceding "no
effect on diff" test, but for the first call to diff_words_flush() the
"wol->buf" would be NULL, so we wouldn't double-free (and
SANITIZE=address would see nothing amiss). With this change we'll
still pass that test, showing that we've also fixed leaks on this
codepath.

We then have to skip the new "no effect on show" test because it
happens to trip over an unrelated memory leak (in revision.c). The
same goes for "move detection with submodules". Both of them pass with
SANITIZE=address though, which would error on the "no effect on show"
test before this change.

Reported-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-17 08:49:13 -07:00
Junio C Hamano ccafbbfb4e Merge branch 'ab/plug-random-leaks'
Plug random memory leaks.

* ab/plug-random-leaks:
  repository.c: free the "path cache" in repo_clear()
  range-diff: plug memory leak in read_patches()
  range-diff: plug memory leak in common invocation
  lockfile API users: simplify and don't leak "path"
  commit-graph: stop fill_oids_from_packs() progress on error and free()
  commit-graph: fix memory leak in misused string_list API
  submodule--helper: fix trivial leak in module_add()
  transport: stop needlessly copying bundle header references
  bundle: call strvec_clear() on allocated strvec
  remote-curl.c: free memory in cmd_main()
  urlmatch.c: add and use a *_release() function
  diff.c: free "buf" in diff_words_flush()
  merge-base: free() allocated "struct commit **" list
  index-pack: fix memory leaks
2022-03-13 22:56:18 +00:00
Junio C Hamano 6d8d81ec36 Merge branch 'ac/usage-string-fixups'
Usage-string normalization.

* ac/usage-string-fixups:
  amend remaining usage strings according to style guide
2022-03-06 21:25:32 -08:00
Ævar Arnfjörð Bjarmason a18d66cefb diff.c: free "buf" in diff_words_flush()
Amend the freeing logic added in e6e045f803 (diff.c: buffer all
output if asked to, 2017-06-29) to free the containing "buf" in
addition to its members.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04 13:24:18 -08:00
Junio C Hamano 362f869ff2 Merge branch 'ab/diff-free-more'
Leakfixes.

* ab/diff-free-more:
  diff.[ch]: have diff_free() free options->parseopts
  diff.[ch]: have diff_free() call clear_pathspec(opts.pathspec)
2022-02-25 15:47:36 -08:00
Abhradeep Chakraborty 9e1f22c8ad amend remaining usage strings according to style guide
Usage strings for git (sub)command flags has a style guide that
suggests - first letter should not capitalized (unless required)
and it should skip full-stop at the end of line. But there are
some files where usage-strings do not follow the above mentioned
guide.

Amend the usage strings that don't follow the style convention/guide.

Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 14:43:10 -08:00
Junio C Hamano 9a160990ef Merge branch 'js/diff-filter-negation-fix'
"git diff --diff-filter=aR" is now parsed correctly.

* js/diff-filter-negation-fix:
  diff-filter: be more careful when looking for negative bits
  diff.c: move the diff filter bits definitions up a bit
  docs(diff): lose incorrect claim about `diff-files --diff-filter=A`
2022-02-16 15:14:30 -08:00
Junio C Hamano 90b7153806 Merge branch 'en/remerge-diff'
"git log --remerge-diff" shows the difference from mechanical merge
result and the result that is actually recorded in a merge commit.

* en/remerge-diff:
  diff-merges: avoid history simplifications when diffing merges
  merge-ort: mark conflict/warning messages from inner merges as omittable
  show, log: include conflict/warning messages in --remerge-diff headers
  diff: add ability to insert additional headers for paths
  merge-ort: format messages slightly different for use in headers
  merge-ort: mark a few more conflict messages as omittable
  merge-ort: capture and print ll-merge warnings in our preferred fashion
  ll-merge: make callers responsible for showing warnings
  log: clean unneeded objects during `log --remerge-diff`
  show, log: provide a --remerge-diff capability
2022-02-16 15:14:29 -08:00
Ævar Arnfjörð Bjarmason 6ee36364eb diff.[ch]: have diff_free() free options->parseopts
The "struct option" added in 4a28847839 (diff.c: prepare to use
parse_options() for parsing, 2019-01-27) would be free'd in the case
of diff_setup_done() being called.

But not all codepaths that allocate it reach that,
e.g. "t6427-diff3-conflict-markers.sh" will now free memory that it
didn't free before. By using FREE_AND_NULL() here (which
diff_setup_done() also does) we ensure that we free the memory, and
that we won't have double-free's.

Before this running:

    ./t6427-diff3-conflict-markers.sh -vixd --run=7

Would report:

    SUMMARY: LeakSanitizer: 7823 byte(s) leaked in 6 allocation(s).

But now we'll report:

    SUMMARY: LeakSanitizer: 703 byte(s) leaked in 5 allocation(s).

I.e. the largest leak in that particular test has now been addressed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16 13:50:37 -08:00
Ævar Arnfjörð Bjarmason 244c27242f diff.[ch]: have diff_free() call clear_pathspec(opts.pathspec)
Have the diff_free() function call clear_pathspec(). Since the
diff_flush() function calls this all its callers can be simplified to
rely on it instead.

When I added the diff_free() function in e900d494dc (diff: add an API
for deferred freeing, 2021-02-11) I simply missed this, or wasn't
interested in it. Let's consolidate this now. This means that any
future callers (and I've got revision.c in mind) that embed a "struct
diff_options" can simply call diff_free() instead of needing know that
it has an embedded pathspec.

This does fix a bunch of leaks, but I can't mark any test here as
passing under the SANITIZE=leak testing mode because in
886e1084d7 (builtin/: add UNLEAKs, 2017-10-01) an UNLEAK(rev) was
added, which plasters over the memory
leak. E.g. "t4011-diff-symlink.sh" would report fewer leaks with this
fix, but because of the UNLEAK() reports none.

I'll eventually loop around to removing that UNLEAK(rev) annotation as
I'll fix deeper issues with the revisions API leaking. This is one
small step on the way there, a new freeing function in revisions.c
will want to call this diff_free().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16 13:50:13 -08:00
Elijah Newren 95433eeed9 diff: add ability to insert additional headers for paths
When additional headers are provided, we need to
  * add diff_filepairs to diff_queued_diff for each paths in the
    additional headers map which, unless that path is part of
    another diff_filepair already found in diff_queued_diff
  * format the headers (colorization, line_prefix for --graph)
  * make sure the various codepaths that attempt to return early
    if there are "no changes" take into account the headers that
    need to be shown.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02 10:02:28 -08:00
Johannes Schindelin 75408ca949 diff-filter: be more careful when looking for negative bits
The `--diff-filter=<bits>` option allows to filter the diff by certain
criteria, for example `R` to only show renamed files. It also supports
negating a filter via a down-cased letter, i.e. `r` to show _everything
but_ renamed files.

However, the code is a bit overzealous when trying to figure out whether
`git diff` should start with all diff-filters turned on because the user
provided a lower-case letter: if the `--diff-filter` argument starts
with an upper-case letter, we must not start with all bits turned on.

Even worse, it is possible to specify the diff filters in multiple,
separate options, e.g. `--diff-filter=AM [...] --diff-filter=m`.

Let's accumulate the include/exclude filters independently, and only
special-case the "only exclude filters were specified" case after
parsing the options altogether.

Note: The code replaced by this commit took pains to avoid setting any
unused bits of `options->filter`. That was unnecessary, though, as all
accesses happen via the `filter_bit_tst()` function using specific bits,
and setting the unused bits has no effect. Therefore, we can simplify
the code by using `~0` (or in this instance, `~<unwanted-bit>`).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-28 10:18:18 -08:00
Johannes Schindelin 4d4d4eaa7b diff.c: move the diff filter bits definitions up a bit
This prepares for a more careful handling of the `--diff-filter`
options over the next few commits.

This commit is best viewed with `--color-moved`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-28 10:18:17 -08:00
Junio C Hamano c17de5a505 Merge branch 'ja/i18n-similar-messages'
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.

* ja/i18n-similar-messages:
  i18n: turn even more messages into "cannot be used together" ones
  i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
  i18n: factorize "--foo outside a repository"
  i18n: refactor "unrecognized %(foo) argument" strings
  i18n: factorize "no directory given for --foo"
  i18n: factorize "--foo requires --bar" and the like
  i18n: tag.c factorize i18n strings
  i18n: standardize "cannot open" and "cannot read"
  i18n: turn "options are incompatible" into "cannot be used together"
  i18n: refactor "%s, %s and %s are mutually exclusive"
  i18n: refactor "foo and bar are mutually exclusive"
2022-01-10 11:52:56 -08:00
Junio C Hamano 2b755b3371 Merge branch 'pw/diff-color-moved-fix'
Correctness and performance update to "diff --color-moved" feature.

* pw/diff-color-moved-fix:
  diff --color-moved: intern strings
  diff: use designated initializers for emitted_diff_symbol
  diff --color-moved-ws=allow-indentation-change: improve hash lookups
  diff --color-moved: stop clearing potential moved blocks
  diff --color-moved: shrink potential moved blocks as we go
  diff --color-moved: unify moved block growth functions
  diff --color-moved: call comparison function directly
  diff --color-moved-ws=allow-indentation-change: simplify and optimize
  diff: simplify allow-indentation-change delta calculation
  diff --color-moved: avoid false short line matches and bad zebra coloring
  diff --color-moved=zebra: fix alternate coloring
  diff --color-moved: rewind when discarding pmb
  diff --color-moved: factor out function
  diff --color-moved: clear all flags on blocks that are too short
  diff --color-moved: add perf tests
2022-01-05 14:01:29 -08:00
Jean-Noël Avila 246cac8505 i18n: turn even more messages into "cannot be used together" ones
Even if some of these messages are not subject to gettext i18n, this
helps bring a single style of message for a given error type.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05 13:31:00 -08:00
Jean-Noël Avila c488182903 i18n: refactor "%s, %s and %s are mutually exclusive"
Use placeholders for constant tokens. The strings are turned into
"cannot be used together"

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05 13:29:23 -08:00
Phillip Wood 72962e8b3c diff --color-moved: intern strings
Taking inspiration from xdl_classify_record() assign an id to each
addition and deletion such that lines that match for the current
--color-moved-ws mode share the same unique id. This reduces the
number of hash lookups a little (calculating the ids still involves
one hash lookup per line) but the main benefit is that when growing
blocks of potentially moved lines we can replace string comparisons
which involve chasing a pointer with a simple integer comparison. On a
large diff this commit reduces the time to run 'diff --color-moved' by
37% compared to the previous commit and 31% compared to master, for
'diff --color-moved-ws=allow-indentation-change' the reduction is 28%
compared to the previous commit and 96% compared to master. There is
little change in the performance of 'git log --patch' as the diffs are
smaller.

Test                                                                  HEAD^              HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.33+0.05)    0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.88(0.81+0.06)    0.55(0.50+0.04) -37.5%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.85(0.79+0.06)    0.61(0.54+0.06) -28.2%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16(1.07+0.08)    1.15(1.09+0.05)  -0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.31(1.22+0.08)    1.29(1.19+0.09)  -1.5%
4002.6: log --color-moved-ws=allow-indentation-change                 1.32(1.24+0.08)    1.31(1.18+0.13)  -0.8%

Test                                                                  master             HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.33+0.05)   0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.80 (0.75+0.04)   0.55(0.50+0.04) -31.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change  14.20(14.15+0.05)   0.61(0.54+0.06) -95.7%
4002.4: log --no-color-moved --no-color-moved-ws                      1.15 (1.05+0.09)   1.15(1.09+0.05)  +0.0%
4002.5: log --color-moved --no-color-moved-ws                         1.30 (1.19+0.11)   1.29(1.19+0.09)  -0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.70 (1.63+0.06)   1.31(1.18+0.13) -22.9%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood b4a5c5c419 diff: use designated initializers for emitted_diff_symbol
This makes it clearer which fields are being explicitly initialized
and will simplify the next commit where we add a new field to the
struct.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood 25e61909e9 diff --color-moved-ws=allow-indentation-change: improve hash lookups
As libxdiff does not have a whitespace flag to ignore the indentation
the code for --color-moved-ws=allow-indentation-change uses
XDF_IGNORE_WHITESPACE and then filters out any hash lookups where
there are non-indentation changes. This filtering is inefficient as
we have to perform another string comparison.

By using the offset data that we have already computed to skip the
indentation we can avoid using XDF_IGNORE_WHITESPACE and safely remove
the extra checks which improves the performance by 11% and paves the
way for the elimination of string comparisons in the next commit.

This change slightly increases the run time of other --color-moved
modes. This could be avoided by using different comparison functions
for the different modes but after the next two commits there is no
measurable benefit in doing so.

There is a change in behavior for lines that begin with a form-feed or
vertical-tab character. Since b46054b374 ("xdiff: use
git-compat-util", 2019-04-11) xdiff does not treat '\f' or '\v' as
whitespace characters. This means that lines starting with those
characters are never considered to be blank and never match a line
that does not start with the same character. After this patch a line
matching "^[\f\v\r]*[ \t]*$" is considered to be blank by
--color-moved-ws=allow-indentation-change and lines beginning
"^[\f\v\r]*[ \t]*" can match another line if the suffixes match. This
changes the output of git show for d18f76dccf ("compat/regex: use the
regex engine from gawk for compat", 2010-08-17) as some lines in the
pre-image before a moved block that contain '\f' are now considered
moved as well as they match a blank line before the moved lines in the
post-image. This commit updates one of the tests to reflect this
change.

Test                                                                  HEAD^             HEAD
--------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.33+0.05)   0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.86(0.82+0.04)   0.88(0.84+0.04)  +2.3%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.97(0.94+0.03)   0.86(0.81+0.05) -11.3%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16(1.07+0.09)   1.16(1.06+0.09)  +0.0%
4002.5: log --color-moved --no-color-moved-ws                         1.32(1.26+0.06)   1.33(1.27+0.05)  +0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.35(1.29+0.06)   1.33(1.24+0.08)  -1.5%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood eec7f53b31 diff --color-moved: stop clearing potential moved blocks
moved_block_clear() was introduced in 74d156f4a1 ("diff
--color-moved-ws: fix double free crash", 2018-10-04) to free the
memory that was allocated when initializing a potential moved
block. However since 21536d077f ("diff --color-moved-ws: modify
allow-indentation-change", 2018-11-23) initializing a potential moved
block no longer allocates any memory. Up until the last commit we were
relying on moved_block_clear() to set the `match` pointer to NULL when
a block stopped matching, but since that commit we do not clear a
moved block that does not match so it does not make sense to clear
them elsewhere.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood 0e488f1732 diff --color-moved: shrink potential moved blocks as we go
Rather than setting `match` to NULL and then looping over the list of
potential matched blocks for a second time to remove blocks with no
matches just filter out the blocks with no matches as we go.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood ff046a0066 diff --color-moved: unify moved block growth functions
After the last two commits pmb_advance_or_null() and
pmb_advance_or_null_multi_match() differ only in the comparison they
perform. Lets simplify the code by combining them into a single
function.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood 08fba1076f diff --color-moved: call comparison function directly
This change will allow us to easily combine pmb_advance_or_null() and
pmb_advance_or_null_multi_match() in the next commit. Calling
xdiff_compare_lines() directly rather than using a function pointer
from the hash map has little effect on the run time.

Test                                                                  HEAD^             HEAD
-------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.35+0.03)   0.38(0.32+0.06) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.87(0.83+0.04)   0.87(0.80+0.06) +0.0%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.97(0.92+0.04)   0.97(0.93+0.04) +0.0%
4002.4: log --no-color-moved --no-color-moved-ws                      1.17(1.06+0.10)   1.16(1.10+0.05) -0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.32(1.24+0.08)   1.31(1.22+0.09) -0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.36(1.25+0.10)   1.35(1.25+0.10) -0.7%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood 52d14e166d diff --color-moved-ws=allow-indentation-change: simplify and optimize
If we already have a block of potentially moved lines then as we move
down the diff we need to check if the next line of each potentially
moved line matches the current line of the diff. The implementation of
--color-moved-ws=allow-indentation-change was needlessly performing
this check on all the lines in the diff that matched the current line
rather than just the current line. To exacerbate the problem finding
all the other lines in the diff that match the current line involves a
fuzzy lookup so we were wasting even more time performing a second
comparison to filter out the non-matching lines. Fixing this reduces
time to run
  git diff --color-moved-ws=allow-indentation-change v2.28.0 v2.29.0
by 93% compared to master and simplifies the code.

Test                                                                  HEAD^              HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.35+0.03)   0.38(0.35+0.03)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.86 (0.80+0.06)   0.87(0.83+0.04)  +1.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change  19.01(18.93+0.06)   0.97(0.92+0.04) -94.9%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16 (1.06+0.09)   1.17(1.06+0.10)  +0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.32 (1.25+0.07)   1.32(1.24+0.08)  +0.0%
4002.6: log --color-moved-ws=allow-indentation-change                 1.71 (1.64+0.06)   1.36(1.25+0.10) -20.5%

Test                                                                  master             HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.33+0.05)   0.38(0.35+0.03)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.80 (0.75+0.04)   0.87(0.83+0.04)  +8.7%
4002.3: diff --color-moved-ws=allow-indentation-change large change  14.20(14.15+0.05)   0.97(0.92+0.04) -93.2%
4002.4: log --no-color-moved --no-color-moved-ws                      1.15 (1.05+0.09)   1.17(1.06+0.10)  +1.7%
4002.5: log --color-moved --no-color-moved-ws                         1.30 (1.19+0.11)   1.32(1.24+0.08)  +1.5%
4002.6: log --color-moved-ws=allow-indentation-change                 1.70 (1.63+0.06)   1.36(1.25+0.10) -20.0%

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood 76e32d6193 diff: simplify allow-indentation-change delta calculation
Now that we reliably end a block when the sign changes we don't need
the whitespace delta calculation to rely on the sign.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood eb89352504 diff --color-moved: avoid false short line matches and bad zebra coloring
When marking moved lines it is possible for a block of potential
matched lines to extend past a change in sign when there is a sequence
of added lines whose text matches the text of a sequence of deleted
and added lines. Most of the time either `match` will be NULL or
`pmb_advance_or_null()` will fail when the loop encounters a change of
sign but there are corner cases where `match` is non-NULL and
`pmb_advance_or_null()` successfully advances the moved block despite
the change in sign.

One consequence of this is highlighting a short line as moved when it
should not be. For example

-moved line  # Correctly highlighted as moved
+short line  # Wrongly highlighted as moved
 context
+moved line  # Correctly highlighted as moved
+short line
 context
-short line

The other consequence is coloring a moved addition following a moved
deletion in the wrong color. In the example below the first "+moved
line 3" should be highlighted as newMoved not newMovedAlternate.

-moved line 1 # Correctly highlighted as oldMoved
-moved line 2 # Correctly highlighted as oldMovedAlternate
+moved line 3 # Wrongly highlighted as newMovedAlternate
 context      # Everything else is highlighted correctly
+moved line 2
+moved line 3
 context
+moved line 1
-moved line 3

These false matches are more likely when using --color-moved-ws with
the exception of --color-moved-ws=allow-indentation-change which ties
the sign of the current whitespace delta to the sign of the line to
avoid this problem. The fix is to check that the sign of the new line
being matched is the same as the sign of the line that started the
block of potential matches.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood eb315457f6 diff --color-moved=zebra: fix alternate coloring
b0a2ba4776 ("diff --color-moved=zebra: be stricter with color
alternation", 2018-11-23) sought to avoid using the alternate colors
unless there are two adjacent moved blocks of the same
sign. Unfortunately it contains two bugs that prevented it from fixing
the problem properly. Firstly `last_symbol` is reset at the start of
each iteration of the loop losing the symbol of the last line and
secondly when deciding whether to use the alternate color it should be
checking if the current line is the same sign of the last line, not a
different sign. The combination of the two errors means that we still
use the alternate color when we should do but we also use it when we
shouldn't. This is most noticable when using
--color-moved-ws=allow-indentation-change with hunks like

-this line gets indented
+    this line gets indented

where the post image is colored with newMovedAlternate rather than
newMoved. While this does not matter much, the next commit will change
the coloring to be correct in this case, so lets fix the bug here to
make it clear why the output is changing and add a regression test.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood 0990658bf8 diff --color-moved: rewind when discarding pmb
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood 7dfe427107 diff --color-moved: factor out function
This code is quite heavily indented and having it in its own function
simplifies an upcoming change.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood bea084ba41 diff --color-moved: clear all flags on blocks that are too short
If a block of potentially moved lines is not long enough then the
DIFF_SYMBOL_MOVED_LINE flag is cleared on the matching lines so they
are not marked as moved. To avoid problems when we start rewinding
after an unsuccessful match in a couple of commits time make sure all
the move related flags are cleared, not just DIFF_SYMBOL_MOVED_LINE.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Ævar Arnfjörð Bjarmason 7f14609e29 run-command API users: use strvec_push(), not argv construction
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_push()" to add data to the "args" member.

As noted in the preceding commit this moves us further towards being
able to remove the "argv" member in a subsequent commit

These callers could have used strvec_pushl(), but moving to
strvec_push() makes the diff easier to read, and keeps the arguments
aligned as before.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Ævar Arnfjörð Bjarmason 9865b6e6a4 *.[ch] *_INIT macros: use { 0 } for a "zero out" idiom
In C it isn't required to specify that all members of a struct are
zero'd out to 0, NULL or '\0', just providing a "{ 0 }" will
accomplish that.

Let's also change code that provided N zero'd fields to just
provide one, and change e.g. "{ NULL }" to "{ 0 }" for
consistency. I.e. even if the first member is a pointer let's use "0"
instead of "NULL". The point of using "0" consistently is to pick one,
and to not have the reader wonder why we're not using the same pattern
everywhere.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 14:47:59 -07:00
Derrick Stolee ad90da7351 diff: ignore sparse paths in diffstat
The diff_populate_filespec() method is used to describe the diff after a
merge operation is complete. In order to avoid expanding a sparse index,
the reuse_worktree_file() needs to be adapted to ignore files that are
outside of the sparse-checkout cone. The file names and OIDs used for
this check come from the merged tree in the case of the ORT strategy,
not the index, hence the ability to look into these paths without having
already expanded the index.

The work done by reuse_worktree_file() is only an optimization, and
requires the file being on disk for it to be of any value. Thus, it is
safe to exit the method early if we do not expect the file on disk.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 15:49:04 -07:00
Junio C Hamano 55194925e6 Merge branch 'ab/pickaxe-pcre2'
* ab/pickaxe-pcre2:
  diff: --pickaxe-all typofix
2021-08-06 12:52:15 -07:00
Bagas Sanjaya 11c649b891 diff: --pickaxe-all typofix
When I was fixing fuzzies as I updating po/id.po for 2.33.0 l10n round,
I noticed a triple-dash typo (--pickaxe-all) at diff.c, which according
to git-diff(1) manpage, the correct option name should be --pickaxe-all.

Fix the typo.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-04 10:34:47 -07:00
Junio C Hamano 268055bfde Merge branch 'en/rename-limits-doc'
Documentation on "git diff -l<n>" and diff.renameLimit have been
updated, and the defaults for these limits have been raised.

* en/rename-limits-doc:
  rename: bump limit defaults yet again
  diffcore-rename: treat a rename_limit of 0 as unlimited
  doc: clarify documentation for rename/copy limits
  diff: correct warning message when renameLimit exceeded
2021-07-28 13:18:03 -07:00
Elijah Newren 94b82d5686 rename: bump limit defaults yet again
These were last bumped in commit 92c57e5c1d (bump rename limit
defaults (again), 2011-02-19), and were bumped both because processors
had gotten faster, and because people were getting ugly merges that
caused problems and reporting it to the mailing list (suggesting that
folks were willing to spend more time waiting).

Since that time:
  * Linus has continued recommending kernel folks to set
    diff.renameLimit=0 (maps to 32767, currently)
  * Folks with repositories with lots of renames were happy to set
    merge.renameLimit above 32767, once the code supported that, to
    get correct cherry-picks
  * Processors have gotten faster
  * It has been discovered that the timing methodology used last time
    probably used too large example files.

The last point is probably worth explaining a bit more:

  * The "average" file size used appears to have been average blob size
    in the linux kernel history at the time (probably v2.6.25 or
    something close to it).
  * Since bigger files are modified more frequently, such a computation
    weights towards larger files.
  * Larger files may be more likely to be modified over time, but are
    not more likely to be renamed -- the mean and median blob size
    within a tree are a bit higher than the mean and median of blob
    sizes in the history leading up to that version for the linux
    kernel.
  * The mean blob size in v2.6.25 was half the average blob size in
    history leading to that point
  * The median blob size in v2.6.25 was about 40% of the mean blob size
    in v2.6.25.
  * Since the mean blob size is more than double the median blob size,
    any file as big as the mean will not be compared to any files of
    median size or less (because they'd be more than 50% dissimilar).
  * Since it is the number of files compared that provides the O(n^2)
    behavior, median-sized files should matter more than mean-sized
    ones.

The combined effect of the above is that the file size used in past
calculations was likely about 5x too large.  Combine that with a CPU
performance improvement of ~30%, and we can increase the limits by
a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated
time limits.

Keeping the same approximate time limit probably makes sense for
diff.renameLimit (there is no progress feedback in e.g. git log -p),
but the experience above suggests merge.renameLimit could be extended
significantly.  In fact, it probably would make sense to have an
unlimited default setting for merge.renameLimit, but that would
likely need to be coupled with changes to how progress is displayed.
(See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/
for details in that area.)  For now, let's just bump the approximate
time limit from 10s to 1m.

(Note: We do not want to use actual time limits, because getting results
that depend on how loaded your system is that day feels bad, and because
we don't discover that we won't get all the renames until after we've
put in a lot of work rather than just upfront telling the user there are
too many files involved.)

Using the original time limit of 2s for diff.renameLimit, and bumping
merge.renameLimit from 10s to 60s, I found the following timings using
the simple script at the end of this commit message (on an AWS c5.xlarge
which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"):

      N   Timing
   1300    1.995s
   7100   59.973s

So let's round down to nice even numbers and bump the limits from
400->1000, and from 1000->7000.

Here is the measure_rename_perf script (adapted from
https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/
in particular to avoid triggering the linear handling from
basename-guided rename detection):

    #!/bin/bash

    n=$1; shift

    rm -rf repo
    mkdir repo && cd repo
    git init -q -b main

    mkdata() {
      mkdir $1
      for i in `seq 1 $2`; do
        (sed "s/^/$i /" <../sample
         echo tag: $1
        ) >$1/$i
      done
    }

    mkdata initial $n
    git add .
    git commit -q -m initial

    mkdata new $n
    git add .
    cd new
    for i in *; do git mv $i $i.renamed; done
    cd ..
    git rm -q -rf initial
    git commit -q -m new

    time git diff-tree -M -l0 --summary HEAD^ HEAD

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-15 16:54:34 -07:00
Elijah Newren 05d2c61c67 diff: correct warning message when renameLimit exceeded
The warning when quadratic rename detection was skipped referred to
"inexact rename detection".  For years, the only linear portion of
rename detection was looking for exact renames, so "inexact rename
detection" was an accurate way to refer to the quadratic portion of
rename detection.  However, that changed with commit bd24aa2f97
(diffcore-rename: guide inexact rename detection based on basenames,
2021-02-14).  Let's instead use the term "exhaustive rename detection"
to refer to the quadratic portion.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-15 16:54:24 -07:00
Junio C Hamano 4da281e84d Merge branch 'ab/pickaxe-pcre2'
Rewrite the backend for "diff -G/-S" to use pcre2 engine when
available.

* ab/pickaxe-pcre2: (22 commits)
  xdiff-interface: replace discard_hunk_line() with a flag
  xdiff users: use designated initializers for out_line
  pickaxe -G: don't special-case create/delete
  pickaxe -G: terminate early on matching lines
  xdiff-interface: allow early return from xdiff_emit_line_fn
  xdiff-interface: prepare for allowing early return
  pickaxe -S: slightly optimize contains()
  pickaxe: rename variables in has_changes() for brevity
  pickaxe -S: support content with NULs under --pickaxe-regex
  pickaxe: assert that we must have a needle under -G or -S
  pickaxe: refactor function selection in diffcore-pickaxe()
  perf: add performance test for pickaxe
  pickaxe/style: consolidate declarations and assignments
  diff.h: move pickaxe fields together again
  pickaxe: die when --find-object and --pickaxe-all are combined
  pickaxe: die when -G and --pickaxe-regex are combined
  pickaxe tests: add missing test for --no-pickaxe-regex being an error
  pickaxe tests: test for -G, -S and --find-object incompatibility
  pickaxe tests: add test for "log -S" not being a regex
  pickaxe tests: add test for diffgrep_consume() internals
  ...
2021-07-13 16:52:50 -07:00