Commit Graph

138 Commits

Author SHA1 Message Date
Linus Torvalds
dcb3450fd8 sha1_to_hex() usage cleanup
Somebody on the #git channel complained that the sha1_to_hex() thing uses
a static buffer which caused an error message to show the same hex output
twice instead of showing two different ones.

That's pretty easily rectified by making it uses a simple LRU of a few
buffers, which also allows some other users (that were aware of the buffer
re-use) to be written in a more straightforward manner.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-03 22:06:45 -07:00
Junio C Hamano
710158e3ca diff --stat: show complete rewrites consistently.
The patch format shows complete rewrite as deletion of all old lines
followed by addition of all new lines.  Count lines consistenly with
that when doing diffstat.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-25 23:40:09 -07:00
Junio C Hamano
6973dcaee7 Libify diff-files.
This is the first installment to libify diff brothers.

The updated diff-files uses revision.c::setup_revisions()
infrastructure to parse its command line arguments, which means
the pathname arguments are checked more strictly than before.
The tests are adjusted to separate possibly missing paths from
the rest of arguments with double-dashes, to show the kosher
way.

As Linus pointed out, renaming diff.c to diff-lib.c was simply
stupid, so I am renaming it back.  The new diff-lib.c is to
contain pieces extracted from diff brothers.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-22 02:37:45 -07:00
Junio C Hamano
ba580aeafb diff: move diff.c to diff-lib.c to make room.
Now I am not doing any real "git-diff in C" yet, but this would
help before doing so.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-19 15:38:14 -07:00
Junio C Hamano
85e6326cc3 Merge branch 'fix'
* fix:
  Document git-clone --reference
  Fix filename scaling for binary files
2006-04-19 02:25:29 -07:00
Jonas Fonseca
8d6e10327d Fix filename scaling for binary files
Set maximum filename length for binary files so that scaling won't be
triggered and result in invalid string access.

Signed-off-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-18 14:44:58 -07:00
Junio C Hamano
3a624b346d Fix "git log --stat": make sure to set recursive with --stat.
Just like "patch" format always needs recursive, "diffstat"
format does not make sense without setting recursive.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-18 11:43:09 -07:00
Junio C Hamano
f56ef54174 diff --stat: make sure to set recursive.
Just like "patch" format always needs recursive, "diffstat"
format does not make sense without setting recursive.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-18 11:29:33 -07:00
Johannes Schindelin
2935327394 diff-options: add --patch-with-stat
With this option, git prepends a diffstat in front of the patch.

Since I really, really do not know what a diffstat of a combined diff
("merge diff") should look like, the diffstat is not generated for these.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-15 19:30:27 -07:00
Junio C Hamano
cbdda02404 diff-files --stat: do not dump core with unmerged index.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-15 19:22:48 -07:00
Junio C Hamano
6f4780f9df diff --stat: do not do its own three-dashes.
I missed that "git-diff-* --stat" spits out three-dash separator
on its own without being asked.  Remove it.

When we output commit log followed by diff, perhaps --patch-with-stat,
for downstream consumer, we _would_ want the three-dash between
the message and the diff material, but that logic belongs to the
caller, not diff generator.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-15 14:06:42 -07:00
Junio C Hamano
84981f9ad9 diff --stat: no need to ask funcnames nor context.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-13 21:35:54 -07:00
Johannes Schindelin
ece634d147 diff-options: add --stat (take 2)
... and a fix for an invalid free():


Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-13 16:50:02 -07:00
Johannes Schindelin
d75f7952ef diff-options: add --stat (take 2)
Now, you can say "git diff --stat" (to get an idea how many changes are
uncommitted), or "git log --stat".

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-13 16:48:24 -07:00
Petr Baudis
90c1b08c7d Separate the raw diff and patch with a newline
More friendly for human reading I believe, and possibly friendlier to some
parsers (although only by an epsilon).

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-11 11:17:50 -07:00
Junio C Hamano
86ff1d2012 diff-* --patch-with-raw
This new flag outputs the diff-raw output and diff-patch output
at the same time.  Requested by Cogito.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-10 19:44:18 -07:00
Junio C Hamano
77882f60d9 Retire diffcore-pathspec.
Nobody except diff-stages used it -- the callers instead filtered
the input to diffcore themselves.  Make diff-stages do that as
well and retire diffcore-pathspec.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-10 15:57:24 -07:00
Junio C Hamano
a041d94f29 diff: fix output of total-rewrite diff.
We did not read in the file data before emitting the
total-rewrite diff.  Noticed by Pasky.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-08 20:32:40 -07:00
Junio C Hamano
b4196cf70a Merge branches 'master' and 'jc/combine' into next
* master:
  Add git-clean command
  diff_flush(): leakfix.
  parse_date(): fix parsing 03/10/2006

* jc/combine:
  combine-diff: refactor built-in xdiff interface.
2006-04-05 02:58:14 -07:00
Junio C Hamano
12d81ce598 Merge branch 'fix'
* fix:
  diff_flush(): leakfix.
  parse_date(): fix parsing 03/10/2006
2006-04-05 02:50:54 -07:00
Junio C Hamano
7d6c447145 diff_flush(): leakfix.
We were leaking filepairs when output-format was set to
NO_OUTPUT.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-05 02:48:41 -07:00
Petr Baudis
d01d8c6782 Support for pickaxe matching regular expressions
git-diff-* --pickaxe-regex will change the -S pickaxe to match
POSIX extended regular expressions instead of fixed strings.

The regex.h library is a rather stupid interface and I like pcre too, but
with any luck it will be everywhere we will want to run Git on, it being
POSIX.2 and all. I'm not sure if we can expect platforms like AIX to
conform to POSIX.2 or if win32 has regex.h. We might add a flag to
Makefile if there is a portability trouble potential.

Signed-off-by: Petr Baudis <pasky@suse.cz>
2006-04-04 13:44:15 -07:00
Junio C Hamano
1b0c7174a1 tree/diff header cleanup.
Introduce tree-walk.[ch] and move "struct tree_desc" and
associated functions from various places.

Rename DIFF_FILE_CANON_MODE(mode) macro to canon_mode(mode) and
move it to cache.h.  This macro returns the canonicalized
st_mode value in the host byte order for files, symlinks and
directories -- to be compared with a tree_desc entry.
create_ce_mode(mode) in cache.h is similar but is intended to be
used for index entries (so it does not work for directories) and
returns the value in the network byte order.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-29 23:54:13 -08:00
Mark Wooding
acb7257729 xdiff: Show function names in hunk headers.
The speed of the built-in diff generator is nice; but the function names
shown by `diff -p' are /really/ nice.  And I hate having to choose.  So,
we hack xdiff to find the function names and print them.

xdiff has grown a flag to say whether to dig up the function names.  The
builtin_diff function passes this flag unconditionally.  I suppose it
could parse GIT_DIFF_OPTS, but it doesn't at the moment.  I've also
reintroduced the `function name' into the test suite, from which it was
removed in commit 3ce8f089.

The function names are parsed by a particularly stupid algorithm at the
moment: it just tries to find a line in the `old' file, from before the
start of the hunk, whose first character looks plausible.  Still, it's
most definitely a start.

Signed-off-by: Mark Wooding <mdw@distorted.org.uk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-27 18:43:51 -08:00
Junio C Hamano
b9aa1f9e9d Merge branch 'lt/diffgen' into next
* lt/diffgen:
  true built-in diff: run everything in-core.
2006-03-26 00:15:44 -08:00
Junio C Hamano
cebff98dbe true built-in diff: run everything in-core.
This stops using temporary files when we are using the built-in
diff (including the complete rewrite).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 23:27:01 -08:00
Junio C Hamano
9acf322d69 Merge branch 'lt/diffgen' into next
* lt/diffgen:
  built-in diff: minimum tweaks
  builtin-diff: \No newline at end of file.
  Use a *real* built-in diff generator
2006-03-25 17:44:01 -08:00
Junio C Hamano
3ce8f08944 built-in diff: minimum tweaks
This fixes up a couple of minor issues with the real built-in
diff to be more usable:

 - Omit ---/+++ header unless we emit diff output;

 - Detect and punt binary diff like GNU does;

 - Honor GIT_DIFF_OPTS minimally (only -u<number> and
   --unified=<number> are currently supported);

 - Omit line count of 1 from "@@ -l,k +m,n @@" hunk header
   (i.e. when k == 1 or n == 1)

 - Adjust testsuite for the lack of -p support.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 16:50:00 -08:00
Linus Torvalds
3443546f6e Use a *real* built-in diff generator
This uses a simplified libxdiff setup to generate unified diffs _without_
doing  fork/execve of GNU "diff".

This has several huge advantages, for example:

Before:

	[torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null

	real    0m24.818s
	user    0m13.332s
	sys     0m8.664s

After:

	[torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null

	real    0m4.563s
	user    0m2.944s
	sys     0m1.580s

and the fact that this should be a lot more portable (ie we can ignore all
the issues with doing fork/execve under Windows).

Perhaps even more importantly, this allows us to do diffs without actually
ever writing out the git file contents to a temporary file (and without
any of the shell quoting issues on filenames etc etc).

NOTE! THIS PATCH DOES NOT DO THAT OPTIMIZATION YET! I was lazy, and the
current "diff-core" code actually will always write the temp-files,
because it used to be something that you simply had to do. So this current
one actually writes a temp-file like before, and then reads it into memory
again just to do the diff. Stupid.

But if this basic infrastructure is accepted, we can start switching over
diff-core to not write temp-files, which should speed things up even
further, especially when doing big tree-to-tree diffs.

Now, in the interest of full disclosure, I should also point out a few
downsides:

 - the libxdiff algorithm is different, and I bet GNU diff has gotten a
   lot more testing. And the thing is, generating a diff is not an exact
   science - you can get two different diffs (and you will), and they can
   both be perfectly valid. So it's not possible to "validate" the
   libxdiff output by just comparing it against GNU diff.

 - GNU diff does some nice eye-candy, like trying to figure out what the
   last function was, and adding that information to the "@@ .." line.
   libxdiff doesn't do that.

 - The libxdiff thing has some known deficiencies. In particular, it gets
   the "\No newline at end of file" case wrong. So this is currently for
   the experimental branch only. I hope Davide will help fix it.

That said, I think the huge performance advantage, and the fact that it
integrates better is definitely worth it. But it should go into a
development branch at least due to the missing newline issue.

Technical note: this is based on libxdiff-0.17, but I did some surgery to
get rid of the extraneous fat - stuff that git doesn't need, and seriously
cutting down on mmfile_t, which had much more capabilities than the diff
algorithm either needed or used. In this version, "mmfile_t" is just a
trivial <pointer,length> tuple.

That said, I tried to keep the differences to simple removals, so that you
can do a diff between this and the libxdiff origin, and you'll basically
see just things getting deleted. Even the mmfile_t simplifications are
left in a state where the diffs should be readable.

Apologies to Davide, whom I'd love to get feedback on this all from (I
wrote my own "fill_mmfile()" for the new simpler mmfile_t format: the old
complex format had a helper function for that, but I did my surgery with
the goal in mind that eventually we _should_ just do

	mmfile_t mf;

	buf = read_sha1_file(sha1, type, &size);
	mf->ptr = buf;
	mf->size = size;
	.. use "mf" directly ..

which was really a nightmare with the old "helpful" mmfile_t, and really
is that easy with the new cut-down interfaces).

[ Btw, as any hawk-eye can see from the diff, this was actually generated
  with itself, so it is "self-hosting". That's about all the testing it
  has gotten, along with the above kernel diff, which eye-balls correctly,
  but shows the newline issue when you double-check it with "git-apply" ]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 16:49:58 -08:00
Junio C Hamano
c06c79667c diffcore-rename: somewhat optimized.
This changes diffcore-rename to reuse statistics information
gathered during similarity estimation, and updates the hashtable
implementation used to keep track of the statistics to be
denser.  This seems to give better performance.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-12 03:22:10 -08:00
Linus Torvalds
8676eb4313 Make git diff-generation use a simpler spawn-like interface
Instead of depending of fork() and execve() and doing things in between
the two, make the git diff functions do everything up front, and then do
a single "spawn_prog()" invocation to run the actual external diff
program (if any is even needed).

This actually ends up simplifying the code, and should make it much
easier to make it efficient under broken operating systems (read: Windows).

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-26 16:21:27 -08:00
Junio C Hamano
ee072260db Merge branch 'jc/nostat'
* jc/nostat:
  cache_name_compare() compares name and stage, nothing else.
  "assume unchanged" git: documentation.
  ls-files: split "show-valid-bit" into a different option.
  "Assume unchanged" git: --really-refresh fix.
  ls-files: debugging aid for CE_VALID changes.
  "Assume unchanged" git: do not set CE_VALID with --refresh
  "Assume unchanged" git
2006-02-21 22:33:21 -08:00
Junio C Hamano
297a1aadbe find_unique_abbrev() simplification.
Earlier it did not grok the 0{40} SHA1 very well, but what it
needed to do was to find the shortest 0{N} that is not used as a
valid object name to be consistent with the way names of valid
objects are abbreviated.  This makes some users simpler.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-10 01:51:12 -08:00
Junio C Hamano
5f73076c1a "Assume unchanged" git
This adds "assume unchanged" logic, started by this message in the list
discussion recently:

	<Pine.LNX.4.64.0601311807470.7301@g5.osdl.org>

This is a workaround for filesystems that do not have lstat()
that is quick enough for the index mechanism to take advantage
of.  On the paths marked as "assumed to be unchanged", the user
needs to explicitly use update-index to register the object name
to be in the next commit.

You can use two new options to update-index to set and reset the
CE_VALID bit:

	git-update-index --assume-unchanged path...
	git-update-index --no-assume-unchanged path...

These forms manipulate only the CE_VALID bit; it does not change
the object name recorded in the index file.  Nor they add a new
entry to the index.

When the configuration variable "core.ignorestat = true" is set,
the index entries are marked with CE_VALID bit automatically
after:

 - update-index to explicitly register the current object name to the
   index file.

 - when update-index --refresh finds the path to be up-to-date.

 - when tools like read-tree -u and apply --index update the working
   tree file and register the current object name to the index file.

The flag is dropped upon read-tree that does not check out the index
entry.  This happens regardless of the core.ignorestat settings.

Index entries marked with CE_VALID bit are assumed to be
unchanged most of the time.  However, there are cases that
CE_VALID bit is ignored for the sake of safety and usability:

 - while "git-read-tree -m" or git-apply need to make sure
   that the paths involved in the merge do not have local
   modifications.  This sacrifices performance for safety.

 - when git-checkout-index -f -q -u -a tries to see if it needs
   to checkout the paths.  Otherwise you can never check
   anything out ;-).

 - when git-update-index --really-refresh (a new flag) tries to
   see if the index entry is up to date.  You can start with
   everything marked as CE_VALID and run this once to drop
   CE_VALID bit for paths that are modified.

Most notably, "update-index --refresh" honours CE_VALID and does
not actively stat, so after you modified a file in the working
tree, update-index --refresh would not notice until you tell the
index about it with "git-update-index path" or "git-update-index
--no-assume-unchanged path".

This version is not expected to be perfect.  I think diff
between index and/or tree and working files may need some
adjustment, and there probably needs other cases we should
automatically unmark paths that are marked to be CE_VALID.

But the basics seem to work, and ready to be tested by people
who asked for this feature.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-08 21:54:42 -08:00
Petr Baudis
6a1f79c1f1 Allow diff and index commands to be interrupted
So far, e.g. git-update-index --refresh was basically uninterruptable
by ctrl-c, since it hooked the SIGINT handler, but that handler would
only unlink the lockfile but not actually quit. This makes it propagate
the signal to the default handler.

Note that I expected it to work without resetting the signal handler to
SIG_DFL, but without that it ended in an infinite loop of tgkill()s -
is my glibc violating SUS or what?

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-01 19:47:52 -08:00
Junio C Hamano
6b1ddbdd6e diff --abbrev=<n> option fix.
Earier specifying an abbreviation shorter than minimum fell back
to full 40 letters, which was nonsense.  Make it to fall back to
the minimum number (currently 4).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-28 00:09:39 -08:00
Junio C Hamano
46a6c2620b abbrev cleanup: use symbolic constants
The minimum length of abbreviated object name was hardcoded in
different places to be 4, risking inconsistencies in the future.
Also there were three different "default abbreviation
precision".  Use two C preprocessor symbols to clean up this
mess.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-28 00:09:38 -08:00
Junio C Hamano
82f9d58a39 code comments: spell
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-29 01:32:56 -08:00
Johannes Schindelin
975b31dc6e Handle symlinks graciously
This patch converts a stat() to an lstat() call, thereby fixing the case
when the date of a symlink was not the same as the one recorded in the
index. The included test case demonstrates this.

This is for the case that the symlink points to a non-existing file. If
the file exists, worse things than just an error message happen.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-26 18:33:27 -08:00
Junio C Hamano
7e4a2a8483 avoid asking ?alloc() for zero bytes.
Avoid asking for zero bytes when that change simplifies overall
logic.  Later we would change the wrapper to ask for 1 byte on
platforms that return NULL for zero byte request.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-26 17:23:59 -08:00
Junio C Hamano
47dd0d595d diff: --abbrev option
When I show transcripts to explain how something works, I often
find myself hand-editing the diff-raw output to shorten various
object names in the output.

This adds --abbrev option to the diff family, which shortens
diff-raw output and diff-tree commit id headers.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-19 18:32:44 -08:00
Junio C Hamano
9ce392f482 Move diff.renamelimit out of default configuration.
Otherwise we would end up linking all the unneeded stuff into git-daemon
only to link with git_default_config.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-21 23:00:50 -08:00
H. Peter Anvin
1b1480ff6a rename/copy score parsing updates.
Better variant, which handles stuff like "4.5%" and rejects
"192.168.0.1".  Additionally, make sure numbers are unsigned (I'm making
them unsigned long just for the hell of it), to make sure that
artificial wraparound scenarios don't cause harm.

	-hpa

[jc: with this, -M100 changes its meaning back to 10%.  People
wanting to say "pure renames only" should now say -M100% or
-M1.0; sounds a bit like an earthquake, but arguably things are
more consistent this way ;-)]

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-21 14:54:33 -08:00
Junio C Hamano
9f70b80692 rename detection with -M100 means "exact renames only".
When the user is interested in pure renames, there is no point
doing the similarity scores.  This changes the score argument
parsing to special case -M100 (otherwise, it is a precision
scaled value 0 <= v < 1 and would mean 0.1, not 1.0 --- if you
do mean 0.1, you can say -M1), and optimizes the diffcore_rename
transformation to only look at pure renames in that case.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-21 12:21:24 -08:00
Junio C Hamano
80b1e511d7 diff: --full-index
A new option, --full-index, is introduced to diff family.  This
causes the full object name of pre- and post-images to appear on
the index line of patch formatted output, to be used in
conjunction with --allow-binary-replacement option of git-apply.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-16 16:20:40 -08:00
Junio C Hamano
3299c6f6a8 diff: make default rename detection limit configurable.
A while ago, a rename-detection limit logic was implemented as a
response to this thread:

	http://marc.theaimsgroup.com/?l=git&m=112413080630175

where gitweb was found to be using a lot of time and memory to
detect renames on huge commits.  git-diff family takes -l<num>
flag, and if the number of paths that are rename destination
candidates (i.e. new paths with -M, or modified paths with -C)
are larger than that number, skips rename/copy detection even
when -M or -C is specified on the command line.

This commit makes the rename detection limit easier to use.  You
can have:

	[diff]
		renamelimit = 30

in your .git/config file to specify the default rename detection
limit.  You can override this from the command line; giving 0
means 'unlimited':

	git diff -M -l0

We might want to change the default behaviour, when you do not
have the configuration, to limit it to say 20 paths or so.  This
would also help the diffstat generation after a big 'git pull'.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-15 15:08:27 -08:00
Linus Torvalds
ac1b3d1248 Split up tree diff functions into tree-diff.c library
This makes the tree diff functionality independent of the "git-diff-tree"
program, by splitting the core functionality up into a library file.

This will be needed for when we teach git-rev-list to only follow a
specified set of pathnames, rather than the global revision history.

Most of it is a fairly straightforward code move, but it also involves
some calling convention cleanup, and moving some of the static variables
from diff-tree.c into the options structure.

The actual tree change callback routines also become paramterized by the
diff_options structure, allowing the library functionality to do something
else than just show the diff on stdout.

Right now the only user of this functionality remains git-diff-tree
itself.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-10-22 22:49:51 -07:00
Linus Torvalds
694a764fc2 Handle "-" at beginning of filenames, part 3
This fixes the default built-in exec() of "diff" to add a "--" before the
filenames, so that if a filename starts with a "-", the diff program won't
think it's an option.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-10-18 00:16:45 -07:00
Junio C Hamano
cf9dfc669e Update git-diff-* to use C-style quoting for funny pathnames.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-10-17 17:41:56 -07:00
Junio C Hamano
ec1fcc16af Show original and resulting blob object info in diff output.
This adds more cruft to diff --git header to record the blob SHA1 and
the mode the patch/diff is intended to be applied against, to help the
receiving end fall back on a three-way merge.  The new header looks
like this:

    diff --git a/apply.c b/apply.c
    index 7be5041..8366082 100644
    --- a/apply.c
    +++ b/apply.c
    @@ -14,6 +14,7 @@
     //    files that are being modified, but doesn't apply the patch
     //  --stat does just a diffstat, and doesn't actually apply
    +//  --show-index-info shows the old and new index info for...
    ...

Upon receiving such a patch, if the patch did not apply cleanly to the
target tree, the recipient can try to find the matching old objects in
her object database and create a temporary tree, apply the patch to
that temporary tree, and attempt a 3-way merge between the patched
temporary tree and the target tree using the original temporary tree
as the common ancestor.

The patch lifts the code to compute the hash for an on-filesystem
object from update-index.c and makes it available to the diff output
routine.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-10-07 03:42:00 -07:00