If PATH_MAX on your system is smaller than a path stored, it may cause
buffer overflow and stack corruption in diff_addremove() and diff_change()
functions when running git-diff
Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even if "foo" and/or "bar" does not exist in index, "git diff foo bar"
should not change behaviour drastically from "git diff foo bar baz" or
"git diff foo". A feature that "sometimes works and is handy" is an
unreliable cute hack.
"git diff foo bar" outside a git repository continues to work as a more
colourful alternative to "diff -u" as before.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the base for making symlink detection in the middle fo a pathname
saner and (much) more efficient.
Under various loads, we want to verify that the full path leading up to a
filename is a real directory tree, and that when we successfully do an
'lstat()' on a filename, we don't get a false positive due to a symlink in
the middle of the path that git should have seen as a symlink, not as a
normal path component.
The 'has_symlink_leading_path()' function already did this, and cached
a single level of symlink information, but didn't cache the _lack_ of a
symlink, so the normal behaviour was actually the wrong way around, and we
ended up doing an 'lstat()' on each path component to check that it was a
real directory.
This caches the last detected full directory and symlink entries, and
speeds up especially deep directory structures a lot by avoiding to
lstat() all the directories leading up to each entry in the index.
[ This can - and should - probably be extended upon so that we eventually
never do a bare 'lstat()' on any path entries at *all* when checking the
index, but always check the full path carefully. Right now we do not
generally check the whole path for all our normal quick index
revalidation.
We should also make sure that we're careful about all the invalidation,
ie when we remove a link and replace it by a directory we should
invalidate the symlink cache if it matches (and vice versa for the
directory cache).
But regardless, the basic function needs to be sane to do that. The old
'has_symlink_leading_path()' was not capable enough - or indeed the code
readable enough - to really do that sanely. So I'm pushing this as not
just an optimization, but as a base for further work. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function is about checking for removed work tree item, so name it
accordingly to avoid future confusion.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
948dd34 (diff-index: careful when inspecting work tree items, 2008-03-30)
made the work tree check careful not to be fooled by a new directory that
exists at a place the index expects a blob. For such a change to be a
typechange from blob to submodule, the new directory has to be a
repository.
However, if the index expects a submodule there, we should not insist the
work tree entity to be a repository --- a simple directory that is not a
full fledged repository (even an empty directory would do) should be
considered an unmodified subproject, because that is how a superproject
with a submodule is checked out sparsely by default.
This makes the function check_work_tree_entity() even more careful not to
report a submodule that is not checked out as removed. It fixes the
recently added test in t4027.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The command
git svn clone (URL of an empty SVN repo here)
works, creates an empty git repository. I can perform the initial
commit there, but then, "git svn dcommit" says :
Use of uninitialized value in concatenation (.) or string at .../git-svn line 414.
Committing to ...
Unable to determine upstream SVN information from HEAD history
I guess a correct management of the initial commit in git-svn would be
hard to implement, but at least, the error message can be improved.
First step is something like the patch below, and better would be for
"git svn clone" to warn that it won't be able to do much with the
cloned repo.
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This does not make any difference when running diff-files alone, but if
you internally run run_diff_files() and then run other operations further
on the index, we do not have to run lstat(2) again on entries we already
have checked.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier, if you changed a staged path into a directory in the work tree,
we happily ran lstat(2) on it and found that it exists, and declared that
the user changed it to a gitlink.
This is wrong for two reasons:
(1) It may be a directory, but it may not be a submodule, and in the
latter case, the change we need to report is "the blob at the path
has disappeared". We need to check with resolve_gitlink_ref() to be
consistent with what "git add" and "git update-index --add" does.
(2) lstat(2) may have succeeded only because a leading component of the
path was turned into a symbolic link that points at something that
exists in the work tree. In such a case, the path itself does not
exist anymore, as far as the index is concerned.
This fixes these breakages in diff-index that the previous patch has
exposed.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When skip_unmerged option is not given, unpack_trees() should not just
skip unmerged cache entries but keep them in the result for the caller to
sort them out.
For callers other than diff-index, the incoming index should never be
unmerged, but diff-index is a special case caller.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We will always unpack into our own internal index, but we will take the
source from wherever specified, and we will optionally write the result
to a specified index (optionally, because not everybody even _wants_ any
result: the index diffing really wants to just walk the tree and index
in parallel).
This ends up removing a fair number more lines than it adds, for the
simple reason that we can now skip all the crud that tried to be
oh-so-careful about maintaining our position in the index as we were
traversing and modifying it. Since we don't actually modify the source
index any more, we can just update the 'o->pos' pointer without worrying
about whether an index entry got removed or replaced or added to.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is just a very mechanical conversion, and makes everybody set it to
'&the_index' before calling, but at least it makes it more explicit
where we work with the index.
The next stage would be to split that index usage up into a 'source' and
a 'destination' index, so that we can unpack into a different index than
we started out from.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The internal implementation of diff-index codepath used to use non const
pointer to pass sha1 around, but it did not have to. With this, we can
also lose the private no_sha1[] array, as we can use the public null_sha1[]
array that exists exactly for the same purpose.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Return an error from unpack_trees() instead of calling die(), and exit
with an error in read-tree, builtin-commit, and diff-lib. merge-recursive
already expected an error return from unpack_trees, so it doesn't need to
be changed. The merge function can return negative to abort.
This will be used in builtin-checkout -m.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
As in run_diff_index(), we call unpack_trees() with the oneway_diff()
function in do_diff_cache() now. This makes the function diff_cache()
obsolete.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A plain "git commit" would still run lstat() a lot more than necessary,
because wt_status_print() would cause the index to be repeatedly flushed
and re-read by wt_read_cache(), and that would cause the CE_UPTODATE bit
to be lost, resulting in the files in the index being lstat'ed three
times each.
The reason why wt-status.c ended up invalidating and re-reading the
cache multiple times was that it uses "run_diff_index()", which in turn
uses "read_tree()" to populate the index with *both* the old index and
the tree we want to compare against.
So this patch re-writes run_diff_index() to not use read_tree(), but
instead use "unpack_trees()" to diff the index to a tree. That, in
turn, means that we don't need to modify the index itself, which then
means that we don't need to invalidate it and re-read it!
This, together with the lstat() optimizations, means that "git commit"
on the kernel tree really only needs to lstat() the index entries once.
That noticeably cuts down on the cached timings.
Best time before:
[torvalds@woody linux]$ time git commit > /dev/null
real 0m0.399s
user 0m0.232s
sys 0m0.164s
Best time after:
[torvalds@woody linux]$ time git commit > /dev/null
real 0m0.254s
user 0m0.140s
sys 0m0.112s
so it's a noticeable improvement in addition to being a nice conceptual
cleanup (it's really not that pretty that "run_diff_index()" dirties the
index!)
Doing an "strace -c" on it also shows that as it cuts the number of
lstat() calls by two thirds, it goes from being lstat()-limited to being
limited by getdents() (which is the readdir system call):
Before:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
60.69 0.000704 0 69230 31 lstat
23.62 0.000274 0 5522 getdents
8.36 0.000097 0 5508 2638 open
2.59 0.000030 0 2869 close
2.50 0.000029 0 274 write
1.47 0.000017 0 2844 fstat
After:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
45.17 0.000276 0 5522 getdents
26.51 0.000162 0 23112 31 lstat
19.80 0.000121 0 5503 2638 open
4.91 0.000030 0 2864 close
1.48 0.000020 0 274 write
1.34 0.000018 0 2844 fstat
...
It passes the test-suite for me, but this is another of one of those
really core functions, and certainly pretty subtle, so..
NOTE! The Linux lstat() system call is really quite cheap when everything
is cached, so the fact that this is quite noticeable on Linux is likely to
mean that it is *much* more noticeable on other operating systems. I bet
you'll see a much bigger performance improvement from this on Windows in
particular.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This converts the index explicitly on read and write to its on-disk
format, allowing the in-core format to contain more flags, and be
simpler.
In particular, the in-core format is now host-endian (as opposed to the
on-disk one that is network endian in order to be able to be shared
across machines) and as a result we can dispense with all the
htonl/ntohl on accesses to the cache_entry fields.
This will make it easier to make use of various temporary flags that do
not exist in the on-disk format.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using the helper function to test for absolute paths makes porting easier.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
reverse_diff was a bit-value in disguise, it's merged in the flags now.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier in commit 0781b8a9b2
(add_file_to_index: skip rehashing if the cached stat already
matches), add_file_to_index() were taught not to re-add the path
if it already matches the index.
The change meant well, but was not executed quite right. It
used ie_modified() to see if the file on the work tree is really
different from the index, and skipped adding the contents if the
function says "not modified".
This was wrong. There are three possible comparison results
between the index and the file in the work tree:
- with lstat(2) we _know_ they are different. E.g. if the
length or the owner in the cached stat information is
different from the length we just obtained from lstat(2), we
can tell the file is modified without looking at the actual
contents.
- with lstat(2) we _know_ they are the same. The same length,
the same owner, the same everything (but this has a twist, as
described below).
- we cannot tell from lstat(2) information alone and need to go
to the filesystem to actually compare.
The last case arises from what we call 'racy git' situation,
that can be caused with this sequence:
$ echo hello >file
$ git add file
$ echo aeiou >file ;# the same length
If the second "echo" is done within the same filesystem
timestamp granularity as the first "echo", then the timestamp
recorded by "git add" and the timestamp we get from lstat(2)
will be the same, and we can mistakenly say the file is not
modified. The path is called 'racily clean'. We need to
reliably detect racily clean paths are in fact modified.
To solve this problem, when we write out the index, we mark the
index entry that has the same timestamp as the index file itself
(that is the time from the point of view of the filesystem) to
tell any later code that does the lstat(2) comparison not to
trust the cached stat info, and ie_modified() then actually goes
to the filesystem to compare the contents for such a path.
That's all good, but it should not be used for this "git add"
optimization, as the goal of "git add" is to actually update the
path in the index and make it stat-clean. With the false
optimization, we did _not_ cause any data loss (after all, what
we failed to do was only to update the cached stat information),
but it made the following sequence leave the file stat dirty:
$ echo hello >file
$ git add file
$ echo hello >file ;# the same contents
$ git add file
The solution is not to use ie_modified() which goes to the
filesystem to see if it is really clean, but instead use
ie_match_stat() with "assume racily clean paths are dirty"
option, to force re-adding of such a path.
There was another problem with "git add -u". The codepath
shares the same issue when adding the paths that are found to be
modified, but in addition, it asked "git diff-files" machinery
run_diff_files() function (which is "git diff-files") to list
the paths that are modified. But "git diff-files" machinery
uses the same ie_modified() call so that it does not report
racily clean _and_ actually clean paths as modified, which is
not what we want.
The patch allows the callers of run_diff_files() to pass the
same "assume racily clean paths are dirty" option, and makes
"git-add -u" codepath to use that option, to discover and re-add
racily clean _and_ actually clean paths.
We could further optimize on top of this patch to differentiate
the case where the path really needs re-adding (i.e. the content
of the racily clean entry was indeed different) and the case
where only the cached stat information needs to be refreshed
(i.e. the racily clean entry was actually clean), but I do not
think it is worth it.
This patch applies to maint and all the way up.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ce_match_stat() can be told:
(1) to ignore CE_VALID bit (used under "assume unchanged" mode)
and perform the stat comparison anyway;
(2) not to perform the contents comparison for racily clean
entries and report mismatch of cached stat information;
using its "option" parameter. Give them symbolic constants.
Similarly, run_diff_files() can be told not to report anything
on removed paths. Also give it a symbolic constant for that.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we compare two non-tracked files, or explicitly
specify --no-index, the suggestion to run git-status
is not helpful.
The patch adds a new diff_options bitfield member, no_index, that
is used instead of the special value of -2 of the rev_info field
max_count to indicate that the index is not to be used. This makes
it possible to pass that flag down to diffcore_skip_stat_unmatch(),
which only has one diff_options parameter.
This could even become a cleanup if we removed all assignments of
max_count to a value of -2 (viz. replacement of a magic value with
a self-documenting field name) but I didn't dare to do that so late
in the rc game..
The no_index bit, if set, then tells diffcore_skip_stat_unmatch()
to not account for any skipped stat-mismatches, which avoids the
suggestion to run git-status.
Signed-off-by: Rene Scharfe <rene.scharfe@lsfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The static function read_directory in diff-lib.c is only ever called
with struct path_list lists with .strdup_paths turned on, i.e.
path_list_insert will strdup the paths for us (again). Let's take
advantage of that and stop doing it twice.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time. There are a few files that need
to have trailing whitespaces (most notably, test vectors). The results
still passes the test, and build result in Documentation/ area is unchanged.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-diff -- a/ b/ always defaulted to --no-index, primarily
because the function is_in_index() was implemented quite
incorrectly.
Noticed by Patrick Maaß and Simon Schubert independently,
initial patch was provided by Patrick but I fixed it
differently.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The diff helpers used to do the magic mode canonicalization and all the
other special mode handling by hand ("trust executable bit" and "has
symlink support" handling).
That's bogus. Use "ce_mode_from_stat()" that does this all for us.
This is also going to be required when we add support for links to other
git repositories.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This teaches git-diff-files, git-diff-index and git-diff-tree
backends to exit early under --quiet option.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This introduces a new command-line option: --exit-code. The diff
programs will return 1 for differences, return 0 for equality, and
something else for errors.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows us to create "new file" and "delete file" patches.
It also cleans up the code.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The earlier commit to read from stdin was full of problems, and
this corrects them.
- The mode bits should have been set to satisify S_ISREG(); we
forgot to the S_IFREG bits and hardcoded 0644;
- We did not give escape hatch to name a path whose name is
really "-". Allow users to say "./-" for that;
- Use of xread() was not prepared to see short read (e.g. reading
from tty) nor handing read errors.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows you to say
echo Hello World | git diff x -
to compare the contents of file "x" with the line "Hello World".
This automatically switches to --no-index mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When run from a subdirectory of a repository, the command forgot
to adjust paths given to it with prefix.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Some file systems that can host git repositories and their working copies
do not support symbolic links. But then if the repository contains a symbolic
link, it is impossible to check out the working copy.
This patch enables partial support of symbolic links so that it is possible
to check out a working copy on such a file system. A new flag
core.symlinks (which is true by default) can be set to false to indicate
that the filesystem does not support symbolic links. In this case, symbolic
links that exist in the trees are checked out as small plain files, and
checking in modifications of these files preserve the symlink property in
the database (as long as an entry exists in the index).
Of course, this does not magically make symbolic links work on such defective
file systems; hence, this solution does not help if the working copy relies
on that an entry is a real symbolic link.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When specifying an absolute path, or a relative path pointing outside
the working tree, do not fail, but roll your own diffopt parsing,
and execute a --no-index diff.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff sets the exit status to 0 when no changes were found, to 1
when changes were found, and 2 means error.
We imitate this to be able to use "git diff" in the test scripts.
(Actually, keeping in line with the rest of git, -1 is returned
on error, which corresponds to an exit status 255).
To find out if the diff is not empty, a member called
"found_changes" was introduced in struct diff_options, which is
set in builtin_diff() and fn_out_consume().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
"git-diff-files --cc" to show conflicts during merge did not pass
the correct mode information for the working tree down, and showed
bogus combined diff.
Signed-off-by: Junio C Hamano <junkio@cox.net>
With this flag and given two paths, git-diff-files behaves as a GNU diff
lookalike (plus the git goodies like --check, colour, etc.). This flag
is also available in git-diff. It also works outside of a git repository.
In addition, if git-diff{,-files} is called without revision or stage
parameter, and with exactly two paths at least one of which is not tracked,
the default is --no-index.
So, you can now say
git diff /etc/inittab /etc/fstab
and it actually works!
This also unifies the duplicated argument parsing between cmd_diff_files()
and builtin_diff_files().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When we do not trust executable bit from lstat(2), we copied
existing ce_mode bits without checking if the filesystem object
is a regular file (which is the only thing we apply the "trust
executable bit" business) nor if the blob in the index is a
regular file (otherwise, we should do the same as registering a
new regular file, which is to default non-executable).
Noticed by Johannes Sixt.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Warning: this changes the semantics.
This makes "git blame" without any positive rev to start digging
from the working tree copy, which is made into a fake commit
whose sole parent is the HEAD.
It also adds --contents <file> option to pretend as if the
working tree copy has the contents of the named file. You can
use '-' to make the command read from the standard input.
If you want the command to start annotating from the HEAD
commit, you need to explicitly give HEAD parameter.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This updates the way diffcore represents an unmerged pair
somewhat. It used to be that entries with mode=0 on both sides
were used to represent an unmerged pair, but now it has an
explicit flag. This is to allow diff-index --cached to report
the entry from the tree when the path is unmerged in the index.
This is used in updating "git reset <tree> -- <path>" to restore
absense of the path in the index from the tree.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This implements a 3-way diff between the HEAD commit, the state in the
index, and the working directory. This is like the n-way diff for a
merge, and uses much of the same code. It is invoked with the -c flag
to git-diff-index, which it already accepted and did nothing with.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This abstracts away the size of the hash values when copying them
from memory location to memory location, much as the introduction
of hashcmp abstracted away hash value comparsion.
A few call sites were using char* rather than unsigned char* so
I added the cast rather than open hashcpy to be void*. This is a
reasonable tradeoff as most call sites already use unsigned char*
and the existing hashcmp is also declared to be unsigned char*.
[jc: Splitted the patch to "master" part, to be followed by a
patch for merge-recursive.c which is not in "master" yet.
Fixed the cast in the latter hunk to combine-diff.c which was
wrong in the original.
Also converted ones left-over in combine-diff.c, diff-lib.c and
upload-pack.c ]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduces global inline:
hashcmp(const unsigned char *sha1, const unsigned char *sha2)
Uses memcmp for comparison and returns the result based on the length of
the hash name (a future runtime decision).
Acked-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We've had this notion of a "object_list" for a long time, which eventually
grew a "name" member because some users (notably git-rev-list) wanted to
name each object as it is generated.
That object_list is great for some things, but it isn't all that wonderful
for others, and the "name" member is generally not used by everybody.
This patch splits the users of the object_list array up into two: the
traditional list users, who want the list-like format, and who don't
actually use or want the name. And another class of users that really used
the list as an extensible array, and generally wanted to name the objects.
The patch is fairly straightforward, but it's also biggish. Most of it
really just cleans things up: switching the revision parsing and listing
over to the array makes things like the builtin-diff usage much simpler
(we now see exactly how many members the array has, and we don't get the
objects reversed from the order they were on the command line).
One of the main reasons for doing this at all is that the malloc overhead
of the simple object list was actually pretty high, and the array is just
a lot denser. So this patch brings down memory usage by git-rev-list by
just under 3% (on top of all the other memory use optimizations) on the
mozilla archive.
It does add more lines than it removes, and more importantly, it adds a
whole new infrastructure for maintaining lists of objects, but on the
other hand, the new dynamic array code is pretty obvious. The change to
builtin-diff-tree.c shows a fairly good example of why an array interface
is sometimes more natural, and just much simpler for everybody.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Since structures with `flexible array members' are an incomplete datatype ANSI
C99 forbids creating instances of them. This patch removes such an instance
from `diff-lib.c' and replaces it with a pointer to a `struct
combine_diff_path'. Since all neccessary memory is allocated at once the number
of calls to `xmalloc' is not increased.
Signed-off-by: Florian Forster <octo@verplant.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
"diff-index -m" does not mean "do not ignore merges", but means
"pretend missing files match the index".
The previous round tried to address this, but failed because
setup_revisions() ate "-m" flag before the caller had a chance
to intervene.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Dmitry Potapov