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>
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>
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>
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"
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>
"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>
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>
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>
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>
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>
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>
