The diff algorithm used in 'git-blame(1)' is set to 'myers',
without the possibility to change it aside from the `--minimal` option.
There has been long-standing interest in changing the default diff
algorithm to "histogram", and Git 3.0 was floated as a possible occasion
for taking some steps towards that:
https://lore.kernel.org/git/xmqqed873vgn.fsf@gitster.g/
As a preparation for this move, it is worth making sure that the diff
algorithm is configurable where useful.
Make it configurable in the `git-blame(1)` command by introducing the
`--diff-algorithm` option and make honor the `diff.algorithm` config
variable. Keep Myers diff as the default.
Signed-off-by: Antonin Delpeuch <antonin@delpeuch.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
We replaced deprecated macos-13 with macos-14 image in GitHub
Actions CI, but we forgot that the image is for arm64. We have
been seeing a lot of test failures ever since. Switch to arm64
binary for Perforce tests.
* jc/ci-use-arm64-p4-on-macos:
Use Perforce arm64 binary on macOS CI jobs
In a following commit, we are going to check commit signatures, but we
won't have a commit yet, only a commit buffer, and we are going to
discard this commit buffer if the signature is invalid. So it would be
wasteful to create a commit that we might discard, just to be able to
check a commit signature.
It would be simpler instead to be able to check commit signatures
using only a commit buffer instead of a commit.
To be able to do that, let's extract some code from the
check_commit_signature() function into a new verify_commit_buffer()
function, and then let's make check_commit_signature() call
verify_commit_buffer().
Note that this doesn't fundamentally change how
check_commit_signature() works. It used to call parse_signed_commit()
which calls repo_get_commit_buffer(), parse_buffer_signed_by_header()
and repo_unuse_commit_buffer(). Now these 3 functions are called
directly by verify_commit_buffer().
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a following commit we are going to finalize commit buffers with or
without signatures in order to check the signatures and possibly drop
them.
To do so easily and without duplication, let's refactor the current
code that finalizes commit buffers into a new finalize_commit_buffer()
function.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The output table from "git repo structure" is misaligned when displaying
UTF-8 characters (e.g., non-ASCII glyphs). E.g.:
| 仓库结构 | 值 |
| -------------- | ---- |
| * 引用 | |
| * 计数 | 67 |
The previous implementation used simple width formatting with printf()
which didn't properly handle multi-byte UTF-8 characters, causing
misaligned table columns when displaying repository structure
information.
This change modifies the stats_table_print_structure function to use
strbuf_utf8_align() instead of basic printf width specifiers. This
ensures proper column alignment regardless of the character encoding of
the content being displayed.
Also add test cases for strbuf_utf8_align(), a function newly introduced
in "builtin/repo.c".
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The file "builtin/repo.c" uses utf8_strwidth() to calculate the display
width of UTF-8 characters in a table, but the resulting output is still
misaligned. Add test cases for both utf8_strwidth and utf8_strnwidth to
verify that they correctly compute the display width for UTF-8
characters.
Also updated the build configuration in Makefile and meson.build to
include the new test suite in the build process.
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous step replaced deprecated macos-13 image with macos-14
image on GitHub Actions CI. While x86-64 binaries can work there,
because macos-14 images are arm64 based (we could replace it with
macos-14-large that is x86-64), it makes more sense to use arm64
binary there. Without this change, we have been getting unusually
higher rate of failures from random macOS CI jobs railing to run
t98xx series of tests.
Helped-by: Koji Nakamaru <koji.nakamaru@gree.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In add_to_cache(), we treat any directories as submodules, and complain
if we can't resolve their HEAD. This call to resolve_gitlink_ref() was
added by f937bc2f86 (add: error appropriately on repository with no
commits, 2019-04-09), with the goal of improving the error message for
empty repositories.
But we already resolve the submodule HEAD in index_path(), which is
where we find the actual oid we're going to use. Resolving it again here
introduces some downsides:
1. It's more work, since we have to open up the submodule repository's
files twice.
2. There are call paths that get to index_path() without going through
add_to_cache(). For instance, we'd want a similar informative
message if "git diff empty" finds that it can't resolve the
submodule's HEAD. (In theory we can also get there through
update-index, but AFAICT it refuses to consider directories as
submodules at all, and just complains about them).
3. The resolution in index_path() catches more errors that we don't
handle here. In particular, it will validate that the object format
for the submodule matches that of the superproject. This isn't a
bug, since our call in add_to_cache() throws away the oid it gets
without looking at it. But it certainly caused confusion for me
when looking at where the object-format check should go.
So instead of resolving the submodule HEAD in add_to_cache(), let's just
teach the call in index_path() to actually produce an error message
(which it already does for other cases). That's probably what f937bc2f86
should have done in the first place, and it gives us a single point of
resolution when adding a submodule to the index.
The resulting output is slightly more verbose, as we propagate the error
up the call stack, but I think that's OK (and again, matches many other
errors we get when indexing fails).
I've left the text of the error message as-is, though it is perhaps
overly specific. There are many reasons that resolving the submodule
HEAD might fail, though outside of corruption or system errors it is
probably most likely that the submodule HEAD is simply on an unborn
branch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The design of the hash algorithm transition plan is that objects stored
must be entirely in one algorithm since we lack any way to indicate a
mix of algorithms. This also includes submodules, but we have
traditionally not enforced this, which leads to various problems when
trying to clone or check out the the submodule from the remote.
Since this cannot work in the general case, restrict adding a submodule
of a different algorithm to the index. Add tests for git add and git
submodule add that these are rejected.
Note that we cannot check this in git fsck because the malformed
submodule is stored in the tree as an object ID which is either
truncated (when a SHA-256 submodule is added to a SHA-1 repository) or
padded with zeros (when a SHA-1 submodule is added to a SHA-256
repository). We cannot detect even the latter case because someone
could have an actual submodule that actually ends in 24 zeros, which
would be a false positive.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`--branch` and `--long` refer to git-status(1) options but they don’t tell us
what `short-format` and `long-format` are, respectively. And `--null`
mentions “status” but does not link to the command.
Refer to git-config(1) on `--branch` like `--short` does.
`long-format` is the git-status(1) output. So we can just say that
directly.
Replace “status” with a `linkgit` on `--null`.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-credential-osxkeychain skips storing a credential if its "get"
action sets "state[]=osxkeychain:seen=1". This behavior was introduced
in e1ab45b2 (osxkeychain: state to skip unnecessary store operations,
2024-05-15), which appeared in v2.46.
However, this state[] persists even if a credential returned by
"git-credential-osxkeychain get" is invalid and a subsequent helper's
"get" operation returns a valid credential. Another subsequent helper
(such as [1]) may expect git-credential-osxkeychain to store the valid
credential, but the "store" operation is incorrectly skipped because it
only checks "state[]=osxkeychain:seen=1".
To solve this issue, "state[]=osxkeychain:seen" needs to contain enough
information to identify whether the current "store" input matches the
output from the previous "get" operation (and not a credential from
another helper).
Set "state[]=osxkeychain:seen" to a value encoding the credential output
by "get", and compare it with a value encoding the credential input by
"store".
[1]: https://github.com/hickford/git-credential-oauth
Reported-by: Petter Sælen <petter@saelen.eu>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Koji Nakamaru <koji.nakamaru@gree.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now "git diff --check" and "git apply --whitespace=warn/fix" learned
incomplete line is a whitespace error, enable them for this project
to prevent patches to add new incomplete lines to our source to both
code and documentation files.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduced via aea86cf00f (The nineteenth batch, 2025-10-14).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
The final line of a file that lacks the terminating newline at its
end is called an incomplete line. In general they are frowned upon
for many reasons (imagine concatenating two files with "cat A B" and
what happens when A ends in an incomplete line, for example), and
text-oriented tools often mishandle such a line.
Implement checks in "git apply" for incomplete lines, which is off
by default for backward compatibility's sake, so that "git apply
--whitespace={fix,warn,error}" can notice, warn against, and fix
them.
As one of the new test shows, if you modify contents on an
incomplete line in the original and leave the resulting line
incomplete, it is still considered a whitespace error, the reasoning
being that "you'd better fix it while at it if you are making a
change on an incomplete line anyway", which may controversial.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
A patch file represents the incomplete line at the end of the file
with two lines, one that is the usual "context" with " " as the
first letter, "added" with "+" as the first letter, or "removed"
with "-" as the first letter that shows the content of the line,
plus an extra "\ No newline at the end of file" line that comes
immediately after it.
Ever since the apply machinery was written, the "git apply"
machinery parses "\ No newline at the end of file" line
independently, without even knowing what line the incomplete-ness
applies to, simply because it does not even remember what the
previous line was.
This poses a problem if we want to check and warn on an incomplete
line. Revamp the code that parses a fragment, to actually drop the
'\n' at the end of the incoming patch file that terminates a line,
so that check_whitespace() calls made from the code path actually
sees an incomplete as incomplete.
Note that the result of this parsing is not directly used by the
code path that applies the patch. apply_one_fragment() function
already checks if each of the patch text it handles is followed by a
line that begins with a backslash to drop the newline at the end of
the current line it is looking at. In a sense, this patch harmonizes
the behaviour of the parsing side to what is already done in the
application side.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
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>
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>
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>
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>
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>
Git very often uses the terms "object", "reference", or "index" in its
documentation.
However, it's hard to find a clear explanation of these terms and how
they relate to each other in the documentation. The closest candidates
currently are:
1. `gitglossary`. This makes a good effort, but it's an alphabetically
ordered dictionary and a dictionary is not a good way to learn
concepts. You have to jump around too much and it's not possible to
present the concepts in the order that they should be explained.
2. `gitcore-tutorial`. This explains how to use the "core" Git commands.
This is a nice document to have, but it's not necessary to learn how
`update-index` works to understand Git's data model, and we should
not be requiring users to learn how to use the "plumbing" commands
if they want to learn what the term "index" or "object" means.
3. `gitrepository-layout`. This is a great resource, but it includes a
lot of information about configuration and internal implementation
details which are not related to the data model. It also does
not explain how commits work.
The result of this is that Git users (even users who have been using
Git for 15+ years) struggle to read the documentation because they don't
know what the core terms mean, and it's not possible to add links
to help them learn more.
Add an explanation of Git's data model. Some choices I've made in
deciding what "core data model" means:
1. Omit pseudorefs like `FETCH_HEAD`, because it's not clear to me
if those are intended to be user facing or if they're more like
internal implementation details.
2. Don't talk about submodules other than by mentioning how they
relate to trees. This is because Git has a lot of special features,
and explaining how they all work exhaustively could quickly go
down a rabbit hole which would make this document less useful for
understanding Git's core behaviour.
3. Don't discuss the structure of a commit message
(first line, trailers etc).
4. Don't mention configuration.
5. Don't mention the `.git` directory, to avoid getting too much into
implementation details
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git last-modified" was optimized by narrowing the set of paths to
follow as it dug deeper in the history.
* tc/last-modified-active-paths-optimization:
last-modified: implement faster algorithm
Given a set of attribute macros like:
[attr]a1 a2
[attr]a2 a3
...
[attr]a300000 -text
file a1
expanding the attributes for "file" requires expanding "a1" to "a2",
"a2" to "a3", and so on until hitting a non-macro expansion ("-text", in
this case). We implement this via recursion: fill_one() calls
macroexpand_one(), which then recurses back to fill_one(). As a result,
very deep macro chains like the one above can run out of stack space and
cause us to segfault.
The required stack space is fairly small; I needed on the order of
200,000 entries to get a segfault on Linux. So it's unlikely anybody
would hit this accidentally, leaving only malicious inputs. There you
can easily construct a repo which will segfault on clone (we look at
attributes during the checkout step, but you'd see the same trying to do
other operations, like diff in a bare repo). It's mostly harmless, since
anybody constructing such a repo is only preventing victims from cloning
their evil garbage, but it could be a nuisance for hosting sites.
One option to prevent this is to limit the depth of recursion we'll
allow. This is conceptually easy to implement, but it raises other
questions: what should the limit be, and do we need a configuration knob
for it?
The recursion here is simple enough that we can avoid those questions by
just converting it to iteration instead. Rather than iterate over the
states of a match_attr in fill_one(), we'll put them all in a queue, and
the expansion of each can add to the queue rather than recursing. Note
that this is a LIFO queue in order to keep the same depth-first order we
did with the recursive implementation. I've avoided using the word
"stack" in the code because the term is already heavily used to refer to
the stack of .gitattribute files that matches the tree structure of the
repository.
The test uses a limited stack size so we can trigger the problem with a
much smaller input than the one shown above. The value here (3000) is
enough to trigger the issue on my x86_64 Linux machine.
Reported-by: Ben Stav <benstav@miggo.io>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Building "git contacts" script (in contrib/) left the resulting
file unexecutable, which has been corrected.
* dk/make-git-contacts-executable:
perl: also mark git-contacts executable
The build procedure based on meson learned to allow builders to
specify the directory to install HTML documents.
* dk/meson-html-dir:
meson: make GIT_HTML_PATH configurable
Build procedure for Wincred credential helper has been updated.
* tu/credential-wincred-makefile-update:
wincred: align Makefile with other Makefiles in contrib
Ever since 14f9e128 (Define the project whitespace policy,
2008-02-10) added the whitespace rules to .gitattributes, we spelled
the most general rule like so:
* whitespace=!indent,trail,space
in the top-level .gitattributes file. The intent of this line was
described in the commit log message:
- Unless otherwise specified, indent with SP that could be
replaced with HT are not "bad". But SP before HT in the
indent is "bad", and trailing whitespaces are "bad".
It clearly wanted to disable indent-with-non-tab, so !indent is most
likely a misspelt form of '-indent'. Because indent-with-non-tab
has never been enabled by default, by luck this was not causing any
ill effect.
We could either remove "!indent", or spell it "-indent". The
immediate effect would be the same. It would only start to make a
difference when/if we enable indent-with-non-tab by default in
future versions of Git.
Let's take the former option to remove "!indent" from the list. We
would feel the effect first-hand ourselves before anybody else if we
ever decide to change the built-in default whitespace rules, which
would be hidden from us if we decide to rewrite it to "-indent"
instead.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
