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26 commits

Author SHA1 Message Date
Jeff King
85a9a63c92 diff: handle NULL meta-info when spawning external diff
Running this:

  $ touch foo bar
  $ chmod +x foo
  $ git -c diff.external=echo diff --ext-diff --no-index foo bar

results in a segfault. The issue is that run_diff_cmd() passes a NULL
"xfrm_msg" variable to run_external_diff(), which feeds it to
strvec_push(), causing the segfault. The bug dates back to 82fbf269b9
(run_external_diff: use an argv_array for the command line, 2014-04-19),
though it mostly only ever worked accidentally.  Before then, we just
stuck the NULL pointer into a "const char **" array, so our NULL ended
up acting as an extra end-of-argv sentinel (which was OK, because it was
the last thing in the array).

Curiously, though, this is only a problem with --no-index. We set up
xfrm_msg by calling fill_metainfo(). This result may be empty, or may
have text like "index 1234..5678\n", "rename from foo\nrename from
bar\n", etc. In run_external_diff(), we only look at xfrm_msg if the
"other" variable is not NULL. That variable is set when the paths of the
two sides of the diff pair aren't the same (in which case the
destination path becomes "other"). So normally it would kick in only for
a rename, in which case xfrm_msg should not be NULL (it would have the
rename information in it).

But with a "--no-index" of two blobs, we of course have two different
pathnames, and thus end up with a non-NULL "other" filename (which is
always just a repeat of the file2-name), but possibly a NULL xfrm_msg.

So how to fix it? I have a feeling that --no-index always passing
"other" to the external diff command is probably a bug. There was no
rename, and the name is always redundant with existing information we
pass (and this may even cause us to pass a useless "xfrm_msg" that
contains an "index 1234..5678" line). So one option would be to change
that behavior. We don't seem to have ever documented the "other" or
"xfrm_msg" parameters for external diffs.

But I'm not sure what fallout we might have from changing that behavior
now. So this patch takes the less-risky option, and simply teaches
run_external_diff() to avoid passing xfrm_msg when it's NULL. That makes
it agnostic to whether "other" and "xfrm_msg" always come as a pair. It
fixes the segfault now, and if we want to change the --no-index "other"
behavior on top, it will handle that, too.

Reported-by: Wilfred Hughes <me@wilfred.me.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-29 10:37:44 -08:00
Junio C Hamano
a8e2394704 Merge branch 'jc/test-i18ngrep'
Another step to deprecate test_i18ngrep.

* jc/test-i18ngrep:
  tests: teach callers of test_i18ngrep to use test_grep
  test framework: further deprecate test_i18ngrep
2023-11-08 11:04:02 +09:00
Junio C Hamano
6789275d37 tests: teach callers of test_i18ngrep to use test_grep
They are equivalents and the former still exists, so as long as the
only change this commit makes are to rewrite test_i18ngrep to
test_grep, there won't be any new bug, even if there still are
callers of test_i18ngrep remaining in the tree, or when merged to
other topics that add new uses of test_i18ngrep.

This patch was produced more or less with

    git grep -l -e 'test_i18ngrep ' 't/t[0-9][0-9][0-9][0-9]-*.sh' |
    xargs perl -p -i -e 's/test_i18ngrep /test_grep /'

and a good way to sanity check the result yourself is to run the
above in a checkout of c4603c1c (test framework: further deprecate
test_i18ngrep, 2023-10-31) and compare the resulting working tree
contents with the result of applying this patch to the same commit.
You'll see that test_i18ngrep in a few t/lib-*.sh files corrected,
in addition to the manual reproduction.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-02 17:13:44 +09:00
René Scharfe
48944f214c diff --no-index: fix -R with stdin
When -R is given, queue_diff() swaps the mode and name variables of the
two files to produce a reverse diff.  1e3f26542a (diff --no-index:
support reading from named pipes, 2023-07-05) added variables that
indicate whether files are special, i.e named pipes or - for stdin.
These new variables were not swapped, though, which broke the handling
of stdin with with -R.  Swap them like the other metadata variables.

Reported-by: Martin Storsjö <martin@martin.st>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-11 12:05:37 -07:00
Jeff King
e5cb1e3f09 t4053: avoid writing to unopened pipe
This fixes an occasional hang I see when running t4053 with
--verbose-log using dash.

Commit 1e3f26542a (diff --no-index: support reading from named pipes,
2023-07-05) added a test that "diff --no-index" will complain when
comparing a named pipe and a directory. The minimum we need to test this
is to mkfifo the pipe, and then run "git diff --no-index pipe some_dir".
But the test does one thing more: it spawns a background shell process
that opens the pipe for writing, like this:

        {
                (>pipe) &
        } &&

This extra writer _could_ be useful if Git misbehaves and tries to open
the pipe for reading. Without the writer, Git would block indefinitely
and the test would never end. But since we do not have such a bug, Git
does not open the pipe and it is the writing process which will block
indefinitely, since there are no readers. The test addresses this by
running "kill $!" in a test_when_finished block. Since the writer should
be blocking forever, this kill command will reliably find it waiting.

However, this seems to be somewhat racy, in that the writing process
sometimes hangs around even after the "kill". In a normal run of the
test script without options, this doesn't have any effect; the
main test script completes anyway. But with --verbose-log, we spawn a
"tee" process that reads the script output, and it won't end until all
descriptors pointing to its input pipe are closed. And the background
process that is hanging around still has its stderr, etc, pointed into
that pipe.

You can reproduce the situation like this:

  cd t
  ./t4053-diff-no-index.sh --verbose-log --stress

Let that run for a few minutes, and then you'll find that some of the
runs have hung. For example, at 11:53, I ran:

  $ ps xk start o pid,start,command | grep tee | head
   713459 11:48:06 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-9.out
   713527 11:48:06 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-15.out
   719434 11:48:07 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-1.out
   728117 11:48:08 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-5.out
   738738 11:48:09 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-31.out
   739457 11:48:09 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-27.out
   744432 11:48:10 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-21.out
   744471 11:48:10 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-29.out
   761961 11:48:12 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-0.out
   812299 11:48:19 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-8.out

All of these have been hung for several minutes. We can investigate one
and see that it's waiting to get EOF on its input:

  $ strace -p 713459
  strace: Process 713459 attached
  read(0,
  ^C

Who else has that descriptor open?

  $ lsof -a -p 713459 -d 0 +E
  COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF    NODE NAME
  tee     713459 peff    0r  FIFO   0,13      0t0 3943636 pipe 719203,sh,5w 719203,sh,7w 719203,sh,12w 719203,sh,13w
  sh      719203 peff    5w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,7w 719203,sh,12w 719203,sh,13w
  sh      719203 peff    7w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,12w 719203,sh,13w
  sh      719203 peff   12w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,7w 719203,sh,13w
  sh      719203 peff   13w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,7w 719203,sh,12w

It's a shell, presumably a subshell spawned by the main script. Though
it may seem odd, having the same descriptor open several times is not
unreasonable (they're all basically the original stdout/stderr of the
script that has been copied). And they should all close when the process
exits. So what's it doing? Curiously, it will exit as soon as we strace
it:

  $ strace -s 64 -p 719203
  strace: Process 719203 attached
  openat(AT_FDCWD, "pipe", O_WRONLY|O_CREAT|O_TRUNC, 0666) = -1 ENOENT (No such file or directory)
  write(2, "./t4053-diff-no-index.sh: 7: eval: ", 35) = 35
  write(2, "cannot create pipe: Directory nonexistent", 41) = 41
  write(2, "\n", 1)                       = 1
  exit_group(2)                           = ?
  +++ exited with 2 +++

I think what happens is this:

  - it is blocking in the openat() call for the pipe, as we expect (so
    this is definitely the backgrounded subshell mentioned above)

  - strace sends signals (probably STOP/CONT); those cause the kernel to
    stop blocking, but libc will restart the system call automatically

  - by this time, the "pipe" fifo is gone, so we'll actually try to
    create a regular file. But of course the surrounding directory is
    gone, too! So we get ENOENT, and then exit as normal.

So the blocking is something we expect to happen. But what we didn't
expect is for the process to still exist at all! It should have been
killed earlier when the parent process called "kill", but it wasn't. And
we can't catch the race at this point, because it happened much earlier.

One can guess, though, that there is some race with the shell setting up
the signal handling in the backgrounded subshell, and possibly blocking
or ignoring signals at the time that the "kill" is received.  Curiously,
the race does not seem to happen if I use "bash" instead of "dash", so
presumably bash's setup here is more atomic.

One fix might be to try killing the subshell more aggressively, either
using SIGKILL, or looping on kill/wait. But that seems complex and
likely to introduce new problems/races. Instead, we can observe that the
writer is not needed at all. Git will notice the pipe via stat() before
it is ever opened. So we can simply drop the writer subshell entirely.

If we ever changed Git to open the path and fstat() it, this would
result in the test hanging. But we're not likely to do that. After all,
we have to stat() paths to see if they are openable at all (e.g., it
could be a directory), so this seems like a low risk. And anybody who
does make such a change will immediately see the issue, as Git would
hang consistently.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-13 16:30:36 -07:00
Phillip Wood
231e86c10c t4053: avoid race when killing background processes
The test 'diff --no-index reads from pipes' starts a couple of
background processes that write to the pipes that are passed to "diff
--no-index". If the test passes then we expect these processes to exit
as all their output will have been read. However if the test fails
then we want to make sure they do not hang about on the users machine
and the test remembers they should be killed by calling

      test_when_finished  "! kill $!"

after each background process is created. Unfortunately there is a
race where test_when_finished may run before the background process
exits even when all its output has been read resulting in the kill
command succeeding which causes the test to fail. Fix this by ignoring
the exit status of the kill command. If the diff is successful we
could instead wait for the background process to exit and check their
status but that feels like it is testing the platform's printf
implementation rather than git's code.

Reported-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>
2023-08-10 09:16:27 -07:00
Phillip Wood
1e3f26542a diff --no-index: support reading from named pipes
In some shells, such as bash and zsh, it's possible to use a command
substitution to provide the output of a command as a file argument to
another process, like so:

  diff -u <(printf "a\nb\n") <(printf "a\nc\n")

However, this syntax does not produce useful results with "git diff
--no-index". On macOS, the arguments to the command are named pipes
under /dev/fd, and git diff doesn't know how to handle a named pipe. On
Linux, the arguments are symlinks to pipes, so git diff "helpfully"
diffs these symlinks, comparing their targets like "pipe:[1234]" and
"pipe:[5678]".

To address this "diff --no-index" is changed so that if a path given on
the commandline is a named pipe or a symbolic link that resolves to a
named pipe then we read the data to diff from that pipe. This is
implemented by generalizing the code that already exists to handle
reading from stdin when the user passes the path "-".

If the user tries to compare a named pipe to a directory then we die as
we do when trying to compare stdin to a directory.

As process substitution is not support by POSIX this change is tested by
using a pipe and a symbolic link to a pipe.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-05 14:00:28 -07:00
Phillip Wood
df521462f0 t4054: test diff --no-index with stdin
"git diff --no-index" supports reading from stdin with the path "-".
There is no test coverage for this so add a regression test before
changing the code in the next commit.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-05 14:00:28 -07:00
Phillip Wood
498198453d diff --no-index: refuse to compare stdin to a directory
When the user runs

    git diff --no-index file directory

we follow the behavior of POSIX diff and rewrite the arguments as

    git diff --no-index file directory/file

Doing that when "file" is "-" (which means "read from stdin") does not
make sense so we should error out if the user asks us to compare "-" to
a directory. This matches the behavior of GNU diff and diff on *BSD.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-05 14:00:28 -07:00
Ævar Arnfjörð Bjarmason
e5e37517dd tests: mark tests as passing with SANITIZE=leak
This marks tests that have been leak-free since various recent
commits, but which were not marked us such when the memory leak was
fixed. These were mostly discovered with the "check" mode added in
faececa53f (test-lib: have the "check" mode for SANITIZE=leak
consider leak logs, 2022-07-28).

Commits that fixed the last memory leak in these tests. Per narrowing
down when they started to pass under SANITIZE=leak with "bisect":

- t1022-read-tree-partial-clone.sh:
  7e2619d8ff (list_objects_filter_options: plug leak of filter_spec
  strings, 2022-09-08)

- t4053-diff-no-index.sh: 07a6f94a6d (diff-no-index: release prefixed
  filenames, 2022-09-07)

- t6415-merge-dir-to-symlink.sh: bac92b1f39 (Merge branch
  'js/ort-clean-up-after-failed-merge', 2022-08-08).

- t5554-noop-fetch-negotiator.sh:
  66eede4a37 (prepare_repo_settings(): plug leak of config values,
  2022-09-08)

- t2012-checkout-last.sh, t7504-commit-msg-hook.sh,
  t91{15,46,60}-git-svn-*.sh: The in-flight "pw/rebase-no-reflog-action"
  series, upon which this is based:
  https://lore.kernel.org/git/pull.1405.git.1667575142.gitgitgadget@gmail.com/

Let's mark all of these as passing with
"TEST_PASSES_SANITIZE_LEAK=true", to have it regression tested,
including as part of the "linux-leaks" CI job.

Additionally, let's remove the "!SANITIZE_LEAK" prerequisite from
tests that now pass, these were marked as failing in:

- 77e56d55ba (diff.c: fix a double-free regression in a18d66cefb,
  2022-03-17)
- c4d1d52631 (tests: change some 'test $(git) = "x"' to test_cmp,
  2022-03-07)

These were not spotted with the new "check" mode, but manually, it
doesn't cover these sort of prerequisites. There's few enough that we
shouldn't bother to automate it. They'll be going away sooner than
later.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-21 12:32:48 +09:00
Ævar Arnfjörð Bjarmason
2be927f3d1 diff --no-index tests: test mode normalization
When "git diff --no-index X Y" is run the modes of the files being
differ are normalized by canon_mode() in fill_filespec().

I recently broke that behavior in a patch of mine[1] which would pass
all tests, or not, depending on the umask of the git.git checkout.

Let's test for this explicitly. Arguably this should not be the
behavior of "git diff --no-index". We aren't diffing our own objects
or the index, so it might be useful to show mode differences between
files.

On the other hand diff(1) does not do that, and it would be needlessly
distracting when e.g. diffing an extracted tar archive whose contents
is the same, but whose file modes are different.

1. https://lore.kernel.org/git/20210316155829.31242-2-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22 12:22:26 -07:00
Ævar Arnfjörð Bjarmason
271cb303a5 diff --no-index tests: add test for --exit-code
Add a test for --exit-code working with --no-index. There's no reason
to suppose it wouldn't, but we weren't testing for it anywhere in our
tests. Let's fix that blind spot.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22 11:48:41 -07:00
Junio C Hamano
dcd6a8c09a Merge branch 'nd/diff-parseopt-4'
Fourth batch to teach the diff machinery to use the parse-options
API.

* nd/diff-parseopt-4:
  am: avoid diff_opt_parse()
  diff --no-index: use parse_options() instead of diff_opt_parse()
  range-diff: use parse_options() instead of diff_opt_parse()
  diff.c: allow --no-color-moved-ws
  diff-parseopt: convert --color-moved-ws
  diff-parseopt: convert --[no-]color-moved
  diff-parseopt: convert --inter-hunk-context
  diff-parseopt: convert --no-prefix
  diff-parseopt: convert --line-prefix
  diff-parseopt: convert --[src|dst]-prefix
  diff-parseopt: convert --[no-]abbrev
  diff-parseopt: convert --diff-filter
  diff-parseopt: convert --find-object
  diff-parseopt: convert -O
  diff-parseopt: convert --pickaxe-all|--pickaxe-regex
  diff-parseopt: convert -S|-G
  diff-parseopt: convert -l
  diff-parseopt: convert -z
  diff-parseopt: convert --ita-[in]visible-in-index
  diff-parseopt: convert --ws-error-highlight
2019-04-25 16:41:12 +09:00
Nguyễn Thái Ngọc Duy
16bb3d714d diff --no-index: use parse_options() instead of diff_opt_parse()
While at there, move exit() back to the caller. It's easier to see the
flow that way than burying it in diff-no-index.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-24 22:21:24 +09:00
Jeff King
287ab28bfa diff: reuse diff setup for --no-index case
When "--no-index" is in effect (or implied by the arguments), git-diff
jumps early to a special code path to perform that diff. This means we
miss out on some settings like enabling --ext-diff and --textconv by
default.

Let's jump to the no-index path _after_ we've done more setup on
rev.diffopt. Since some of the options don't affect us (e.g., items
related to the index), let's re-order the setup into two blocks (see the
in-code comments).

Note that we also need to stop re-initializing the diffopt struct in
diff_no_index(). This should not be necessary, as it will already have
been initialized by cmd_diff() (and there are no other callers). That in
turn lets us drop the "repository" argument from diff_no_index (which
never made much sense, since the whole point is that you don't need a
repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-24 07:08:34 -08:00
Johannes Sixt
ffd04e92e2 diff: don't attempt to strip prefix from absolute Windows paths
git diff can be invoked with absolute paths. Typically, this triggers
the --no-index case. Then the absolute paths remain in the file names
that are printed in the output.

There is one peculiarity, though: When the command is invoked from a
a sub-directory in a repository, then it is attempted to strip the
sub-directory from the beginning of relative paths. Yet, to detect a
relative path the code just checks for an initial forward slash.
This mistakes a Windows style path like "D:/base" as a relative path
and the output looks like this, for example:

  D:\dir\test\one>git -P diff --numstat D:\dir\base D:\dir\diff
  1       1       ir/{base => diff}/1.txt

where the correct output should be

  D:\dir\test\one>git -P diff --numstat D:\dir\base D:\dir\diff
  1       1       D:/dir/{base => diff}/1.txt

If the sub-directory where 'git diff' is invoked is sufficiently deep
that the prefix becomes longer than the path to be printed, then the
subsequent code accesses the path out of bounds.

Use is_absolute_path() to detect Windows style absolute paths.

One might wonder whether the check for a directory separator that
is visible in the patch context should be changed from == '/' to
is_dir_sep() or not. It turns out not to be necessary. That code
only ever investigates paths that have undergone pathspec
normalization, after which there are only forward slashes even on
Windows.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-22 10:17:50 +09:00
Jeff King
28a4e58021 diff: always try to set up the repository
If we see an explicit "--no-index", we do not bother calling
setup_git_directory_gently() at all. This means that we may
miss out on reading repo-specific config.

It's arguable whether this is correct or not. If we were
designing from scratch, making "git diff --no-index"
completely ignore the repository makes some sense. But we
are nowhere near scratch, so let's look at the existing
behavior:

  1. If you're in the top-level of a repository and run an
     explicit "diff --no-index", the config subsystem falls
     back to reading ".git/config", and we will respect repo
     config.

  2. If you're in a subdirectory of a repository, then we
     still try to read ".git/config", but it generally
     doesn't exist. So "diff --no-index" there does not
     respect repo config.

  3. If you have $GIT_DIR set in the environment, we read
     and respect $GIT_DIR/config,

  4. If you run "git diff /tmp/foo /tmp/bar" to get an
     implicit no-index, we _do_ run the repository setup,
     and set $GIT_DIR (or respect an existing $GIT_DIR
     variable). We find the repo config no matter where we
     started, and respect it.

So we already respect the repository config in a number of
common cases, and case (2) is the only one that does not.
And at least one of our tests, t4034, depends on case (1)
behaving as it does now (though it is just incidental, not
an explicit test for this behavior).

So let's bring case (2) in line with the others by always
running the repository setup, even with an explicit
"--no-index". We shouldn't need to change anything else, as the
implicit case already handles the prefix.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 15:45:45 -07:00
Jeff King
7d8930d903 diff: handle --no-index prefixes consistently
If we see an explicit "git diff --no-index ../foo ../bar",
then we do not set up the git repository at all (we already
know we are in --no-index mode, so do not have to check "are
we in a repository?"), and hence have no "prefix" within the
repository. A patch generated by this command will have the
filenames "a/../foo" and "b/../bar", no matter which
directory we are in with respect to any repository.

However, in the implicit case, where we notice that the
files are outside the repository, we will have chdir()'d to
the top-level of the repository. We then feed the prefix
back to the diff machinery. As a result, running the same
diff from a subdirectory will result in paths that look like
"a/subdir/../../foo".

Besides being unnecessarily long, this may also be confusing
to the user: they don't care about the subdir or the
repository at all; it's just where they happened to be when
running the command. We should treat this the same as the
explicit --no-index case.

One way to address this would be to chdir() back to the
original path before running our diff. However, that's a bit
hacky, as we would also need to adjust $GIT_DIR, which could
be a relative path from our top-level.

Instead, we can reuse the diff machinery's RELATIVE_NAME
option, which automatically strips off the prefix. Note that
this _also_ restricts the diff to this relative prefix, but
that's OK for our purposes: we queue our own diff pairs
manually, and do not rely on that part of the diff code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 15:45:45 -07:00
Junio C Hamano
03761c922b Merge branch 'jc/diff-no-index-d-f'
The usual "git diff" when seeing a file turning into a directory
showed a patchset to remove the file and create all files in the
directory, but "git diff --no-index" simply refused to work.  Also,
when asked to compare a file and a directory, imitate POSIX "diff"
and compare the file with the file with the same name in the
directory, instead of refusing to run.

* jc/diff-no-index-d-f:
  diff-no-index: align D/F handling with that of normal Git
  diff-no-index: DWIM "diff D F" into "diff D/F F"
2015-05-05 21:00:24 -07:00
Junio C Hamano
0615173998 diff-no-index: align D/F handling with that of normal Git
When a commit changes a path P that used to be a file to a directory
and creates a new path P/X in it, "git show" would say that file P
was removed and file P/X was created for such a commit.

However, if we compare two directories, D1 and D2, where D1 has a
file D1/P in it and D2 has a directory D2/P under which there is a
file D2/P/X, and ask "git diff --no-index D1 D2" to show their
differences, we simply get a refusal "file/directory conflict".

Surely, that may be what GNU diff does, but we can do better and it
is easy to do so.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-26 14:08:43 -07:00
Junio C Hamano
c9e1f2c7f2 diff-no-index: DWIM "diff D F" into "diff D/F F"
"git diff --no-index" was supposed to be a poor-man's approach to
allow using Git diff goodies outside of a Git repository, without
having to patch mainstream diff implementations.

Unlike a POSIX diff that treats "diff D F" (or "diff F D") as a
request to compare D/F and F (or F and D/F) when D is a directory
and F is a file, however, we did not accept such a command line and
instead barfed with "file/directory conflict".

Imitate what POSIX diff does and append the basename of the file
after the name of the directory before comparing.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-25 22:39:07 -07:00
Jeff King
c21fc9d0ab t: use test_expect_code instead of hand-rolled comparison
This makes our output in the event of a failure slightly
nicer, and it means that we do not break the &&-chain.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-20 10:20:16 -07:00
Thomas Gummerer
8a19dfa1aa diff: add test for --no-index executed outside repo
470faf9 diff: move no-index detection to builtin/diff.c breaks the error
message for "git diff --no-index", when the command is executed outside
of a git repository and the wrong number of arguments are given. 6df5762
diff: don't read index when --no-index is given fixes the problem.

Add a test to guard against similar breakages in the future.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-16 13:12:33 -08:00
Thomas Gummerer
6df5762db3 diff: don't read index when --no-index is given
git diff --no-index ... currently reads the index, during setup, when
calling gitmodules_config().  This results in worse performance when the
index is not actually needed.  This patch avoids calling
gitmodules_config() when the --no-index option is given.  The times for
executing "git diff --no-index" in the WebKit repository are improved as
follows:

Test                      HEAD~3            HEAD
------------------------------------------------------------------
4001.1: diff --no-index   0.24(0.15+0.09)   0.01(0.00+0.00) -95.8%

An additional improvement of this patch is that "git diff --no-index" no
longer breaks when the index file is corrupt, which makes it possible to
use it for investigating the broken repository.

To improve the possible usage as investigation tool for broken
repositories, setup_git_directory_gently() is also not called when the
--no-index option is given.

Also add a test to guard against future breakages, and a performance
test to show the improvements.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-12 12:23:02 -08:00
Jeff King
546e0fd9e9 diff: handle relative paths in no-index
When diff-no-index is given a relative path to a file outside the
repository, it aborts with error. However, if the file is given
using an absolute path, the diff runs as expected. The two cases
should be treated the same.

Tests and commit message by Tim Henigan.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-06-22 10:20:18 -07:00
Bobby Powers
f3999e0327 diff --no-index: reset temporary buffer lengths on directory iteration
Commit 875b91b (diff --no-index: use strbuf for temporary pathnames,
2012-04-25) introduced a regression when using diff --no-index with
directories.  When iterating through a directory, the switch to strbuf
from heap-allocated char arrays caused paths to form like 'dir/file1',
'dir/file1file2', rather than 'dir/file1', 'dir/file2' as expected.

Avoid this by resetting the paths variables to their original length
before each iteration.

Signed-off-by: Bobby Powers <bobbypowers@gmail.com>
Reviewed-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-05-16 11:17:45 -07:00