That would make it easier to give enhanced feature to the
pickaxe transformation.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Usually, diff frontends populate the output queue with filepairs without
any rename information and call diffcore_std() to sort the renames out.
When --follow is in effect, however, diff-tree family of frontend has a
hack that looks like this:

    diff-tree frontend
    -> diff_tree_sha1()
       . populate diff_queued_diff
       . if --follow is in effect and there is only one change that
         creates the target path, then
       -> try_to_follow_renames()
	  -> diff_tree_sha1() with no pathspec but with -C
	  -> diffcore_std() to find renames
	  . if rename is found, tweak diff_queued_diff and put a
	    single filepair that records the found rename there
    -> diffcore_std()
       . tweak elements on diff_queued_diff by
       - rename detection
       - path ordering
       - pickaxe filtering

We need to skip parts of the second call to diffcore_std() that is related
to rename detection, and do so only when try_to_follow_renames() did find
a rename.  Earlier 1da6175d (Make diffcore_std only can run once before a
diff_flush, 2010-05-06) tried to deal with this issue incorrectly; it
unconditionally disabled any second call to diffcore_std().

This hopefully fixes the breakage.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are two ways a user might want to use "diff --relative":

  1. For a file in a directory, like "subdir/file", the user
     can use "--relative=subdir/" to strip the directory.

  2. To strip part of a filename, like "foo-10", they can
     use "--relative=foo-".

We currently handle both of those situations. However, if the user passes
"--relative=subdir" (without the trailing slash), we produce inconsistent
results. For the unified diff format, we collapse the double-slash of
"a//file" correctly into "a/file". But for other formats (raw, stat,
name-status), we end up with "/file".

We can do what the user means here and strip the extra "/" (and only a
slash).  We are not hurting any existing users of (2) above with this
behavior change because the existing output for this case was nonsensical.

Patch by Jakub, tests and commit message by Jeff King.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When you have a lot of submodules checked out, the time penalty to check
for dirty submodules can easily imply a multiplication of the total time
by the factor 20. This makes the difference between almost instantaneous
(< 2 seconds) and unbearably slow (> 50 seconds) here, since the disk
caches are constantly overloaded.

To this end, the submodule.*.ignore config option was introduced, but it
is per-submodule.

This commit introduces a global config setting to set a default
(porcelain) value for the --ignore-submodules option, keeping the
default at 'none'. It can be overridden by the submodule.*.ignore
setting and by the --ignore-submodules option.

Incidentally, this commit fixes an issue with the overriding logic:
multiple --ignore-submodules options would not clear the previously
set flags.

While at it, fix a typo in the documentation for submodule.*.ignore.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new "ignore" config option controls the default behavior for "git
status" and the diff family. It specifies under what circumstances they
consider submodules as modified and can be set separately for each
submodule.

The command line option "--ignore-submodules=" has been extended to accept
the new parameter "none" for both status and diff.

Users that chose submodules to get rid of long work tree scanning times
might want to set the "dirty" option for those submodules. This brings
back the pre 1.7.0 behavior, where submodule work trees were never
scanned for modifications. By using "--ignore-submodules=none" on the
command line the status and diff commands can be told to do a full scan.

This option can be set to the following values (which have the same name
and meaning as for the "--ignore-submodules" option of status and diff):

"all": All changes to the submodule will be ignored.

"dirty": Only differences of the commit recorded in the superproject and
	the submodules HEAD will be considered modifications, all changes
	to the work tree of the submodule will be ignored. When using this
	value, the submodule will not be scanned for work tree changes at
	all, leading to a performance benefit on large submodules.

"untracked": Only untracked files in the submodules work tree are ignored,
	a changed HEAD and/or modified files in the submodule will mark it
	as modified.

"none" (which is the default): Either untracked or modified files in a
	submodules work tree or a difference between the subdmodules HEAD
	and the commit recorded in the superproject will make it show up
	as changed. This value is added as a new parameter for the
	"--ignore-submodules" option of the diff family and "git status"
	so the user can override the settings in the configuration.
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Part of a campaign for unstuck forms of options.

[jn: with some refactoring]
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As an optimization, the diff_opt_parse() switchboard has
a single case for all the --stat-* options.  Split it
off into a separate function so we can enhance it
without bringing code dangerously close to the right
margin.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change the option parsing logic in revision.c to accept separate forms
like `-S foo' in addition to `-Sfoo'. The rest of git already accepted
this form, but revision.c still used its own option parsing.

Short options affected are -S<string>, -l<num> and -O<orderfile>, for
which an empty string wouldn't make sense, hence -<option> <arg> isn't
ambiguous.

This patch does not handle --stat-name-width and --stat-width, which are
special-cases where diff_long_opt do not apply. They are handled in a
separate patch to ease review.

Original patch by Matthieu Moy, plus refactoring by Jonathan Nieder.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It introduced a macro to reduce repeated assignments to three fields,
but an unrelated and incorrect change snuck in by mistake, which broke
commands like "git diff-files -p --submodule".

Noticed by Sven Verdoolaege.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When --graph is in effect, the line-prefix typically has colored graph
line segments and ends with reset.  The color sequence "set" given to
this function is for showing the metainfo part of the patch text and
(1) it should not be applied to the graph lines, and (2) it will be
reset at the end of line_prefix so it won't be in effect anyway.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In some use cases it is not desirable that "git status" considers
submodules that only contain untracked content as dirty. This may happen
e.g. when the submodule is not under the developers control and not all
build generated files have been added to .gitignore by the upstream
developers. Using the "untracked" parameter for the "--ignore-submodules"
option disables checking for untracked content and lets git diff report
them as changed only when they have new commits or modified content.

Sometimes it is not wanted to have submodules show up as changed when they
just contain changes to their work tree (this was the behavior before
1.7.0). An example for that are scripts which just want to check for
submodule commits while ignoring any changes to the work tree. Also users
having large submodules known not to change might want to use this option,
as the - sometimes substantial - time it takes to scan the submodule work
tree(s) is saved when using the "dirty" parameter.

And if you want to ignore any changes to submodules, you can now do that
by using this option without parameters or with "all" (when the config
option status.submodulesummary is set, using "all" will also suppress the
output of the submodule summary).

A new function handle_ignore_submodules_arg() is introduced to parse this
option new to "git status" in a single location, as "git diff" already
knew it.
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In some use cases it is not desirable that the diff family considers
submodules that only contain untracked content as dirty. This may happen
e.g. when the submodule is not under the developers control and not all
build generated files have been added to .gitignore by the upstream
developers. Using the "untracked" parameter for the "--ignore-submodules"
option disables checking for untracked content and lets git diff report
them as changed only when they have new commits or modified content.

Sometimes it is not wanted to have submodules show up as changed when they
just contain changes to their work tree. An example for that are scripts
which just want to check for submodule commits while ignoring any changes
to the work tree. Also users having large submodules known not to change
might want to use this option, as the - sometimes substantial - time it
takes to scan the submodule work tree(s) is saved.
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The textconv functionality allows one to convert a file into text before
running diff. But this functionality can be useful to other features
such as blame.
Signed-off-by: NAxel Bonnet <axel.bonnet@ensimag.imag.fr>
Signed-off-by: NClément Poulain <clement.poulain@ensimag.imag.fr>
Signed-off-by: NDiane Gasselin <diane.gasselin@ensimag.imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A bug was introduced in 3e97c7c6
(No diff -b/-w output for all-whitespace changes, Nov 19 2009)
that made the lines:

  diff --git a/bar b/sub/bar
  similarity index 100%
  rename from bar
  rename to sub/bar

disappear from "git show -C -C" output when file bar is a binary
file.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

'--color-words' algorithm can be described as:

  1. collect a the minus/plus lines of a diff hunk, divided into
     minus-lines and plus-lines;

  2. break both minus-lines and plus-lines into words and
     place them into two mmfile_t with one word for each line;

  3. use xdiff to run diff on the two mmfile_t to get the words level diff;

And for the common parts of the both file, we output the plus side text.
diff_words->current_plus is used to trace the current position of the plus file
which printed. diff_words->last_minus is used to trace the last minus word
printed.

For '--graph' to work with '--color-words', we need to output the graph prefix
on each line of color words output. Generally, there are two conditions on
which we should output the prefix.

  1. diff_words->last_minus == 0 &&
     diff_words->current_plus == diff_words->plus.text.ptr

     that is: the plus text must start as a new line, and if there is no minus
     word printed, a graph prefix must be printed.

  2. diff_words->current_plus > diff_words->plus.text.ptr &&
     *(diff_words->current_plus - 1) == '\n'

     that is: a graph prefix must be printed following a '\n'
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since the graph prefix will be printed when calling
emit_line, so the functions should be used to emit a
complete line out once a time. No one should call
emit_line to just output some strings instead of a
complete line.
Use a strbuf to compose the whole line, and then
call emit_line to output it once.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change output from diff with -p/--dirstat/--binary/--numstat/--stat/
--shortstat/--check/--summary options to align with graph paddings.

Thanks Jeff King <peff@peff.net> for reporting the '--summary' bug and
his initial patch.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The callback can be used to add some prefix string to each line of
diff output.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In the metainfo section of git diffs there's an "index" line providing
abbreviated (unless --full-index is used) blob SHA1s from the
pre-/post-images used to generate the diff. These provide hints that
can be used to reconstruct a 3-way merge when applying the patch
(see the --3way option to 'git am' for more details).

In order for this to work, however, the blob SHA1s must not be
abbreviated into ambiguity.

This patch eliminates the possible ambiguity by using find_unique_abbrev()
to produce the abbreviated SHA1s (instead of blind abbreviation by way of
"%.*s").

A testcase verifying the fix is also included.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Coloring the extended headers where done as a whole not per line. less with
option -R (which is the default from git) does not support this coloring
mode because of performance reasons. The -r option would be an alternative
but has problems with lines that are longer than the screen. Therefore
stick to the idiom to color each line separately. The problem is, that the
result of ill_metainfo() will also be used as an parameter to an external
diff driver, so we need to disable coloring in this case.

Because coloring is now done inside fill_metainfo() we can simply add this
string to the diff header and therefore keep the last newline in the
extended header. This results also into the fact that the external diff
driver now gets this last newline too. Which is a change in behavior
but a good one.
Signed-off-by: NBert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Here we simply make --patch a synonym for -p, whose mnemonic was "patch"
all along.
Signed-off-by: NWill Palmer <wmpalmer@gmail.com>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

With new configuration "diff.noprefix", "git diff" does not show a source or destination prefix ala "git diff --no-prefix".
Signed-off-by: NEli Collins <eli@cloudera.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When file renames/copies detection is turned on, the
second diffcore_std will degrade a 'C' pair to a 'R' pair.

And this may happen when we run 'git log --follow' with
hard copies finding. That is, the try_to_follow_renames()
will run diffcore_std to find the copies, and then
'git log' will issue another diffcore_std, which will reduce
'src->rename_used' and recognize this copy as a rename.
This is not what we want.

So, I think we really don't need to run diffcore_std more
than one time.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Refactor the diff_queue_struct code, this macro help
to reset the structure.
Signed-off-by: NBo Yang <struggleyb.nku@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

xdi_diff_outf() overrides the structure members of its last parameter,
ignoring any value that callers pass in.  It's no surprise then that all
callers pass a pointer to an uninitialized structure.  They also don't
read it after the call, so the parameter is neither used for input nor
for output.   Turn it into a local variable of xdi_diff_outf().
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Acked-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Ever since the xdiff library had been introduced to git, all its callers
have used the flag XDF_NEED_MINIMAL.  It makes sure that the smallest
possible diff is produced, but that takes quite some time if there are
lots of differences that can be expressed in multiple ways.

This flag makes a difference for only 0.1% of the non-merge commits in
the git repo of Linux, both in terms of diff size and execution time.
The patches there are mostly nice and small.

SungHyun Nam however reported a case in a different repo where a diff
took more than 20 times longer to generate with XDF_NEED_MINIMAL than
without.  Rebasing became really slow.

This patch removes this flag from all callers.  The default of xdiff is
saner because it has minimal to no impact in the normal case of small
diffs and doesn't incur that much of a speed penalty for large ones.

A follow-up patch may introduce a command line option to set the flag if
the user needs it, similar to GNU diff's -d/--minimal.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The diffstat "added" and "changed" fields generally store
line counts; however, for binary files, they store file
sizes. Since we store and print these values as ints, a
diffstat on a file larger than 2G can show a negative size.
Instead, let's use uintmax_t, which should be at least 64
bits on modern platforms.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This teaches the --color-words engine a more general interface that
supports two new modes:

* --word-diff=plain, inspired by the 'wdiff' utility (most similar to
  'wdiff -n <old> <new>'): uses delimiters [-removed-] and {+added+}

* --word-diff=porcelain, which generates an ad-hoc machine readable
  format:
  - each diff unit is prefixed by [-+ ] and terminated by newline as
    in unified diff
  - newlines in the input are output as a line consisting only of a
    tilde '~'

Both of these formats still support color if it is enabled, using it
to highlight the differences.  --color-words becomes a synonym for
--word-diff=color, which is the color-only format.  Also adds some
compatibility/convenience options.

Thanks to Junio C Hamano and Miles Bader for good ideas.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The textconv leak fix introduced two invocations of free() to release
memory pointed by "const char *", which get annoying compiler warning.

builtin_diff calls fill_mmfile fairly early, which in turn
calls diff_populate_filespec, which actually retrieves the
file's blob contents into a buffer. Long ago, this was
sensible as we would need to look at the blobs eventually.

These days, however, we may not ever want those blobs if we
end up using a textconv cache, and for large binary files
(exactly the sort for which you might have a textconv
cache), just retrieving the objects can be costly.

This patch just pushes the fill_mmfile call a bit later, so
we can avoid populating the filespec in some cases.  There
is one thing to note that looks like a bug but isn't. We
push the fill_mmfile down into the first branch of a
conditional. It seems like we would need it on the other
branch, too, but we don't; fill_textconv does it for us (in
fact, before this, we were just writing over the results of
the fill_mmfile on that branch).

Here's a timing sample on a commit with 45 changed jpgs and
avis. The result is fully textconv cached, but we still
wasted a lot of time just pulling the blobs from storage.
The total size of the blobs (source and dest) is about
180M.

  [before]
  $ time git show >/dev/null
  real    0m0.352s
  user    0m0.148s
  sys     0m0.200s

  [after]
  $ time git show >/dev/null
  real    0m0.009s
  user    0m0.004s
  sys     0m0.004s

And that's on a warm cache. On a cold cache, the "after"
case is not much worse, but the "before" case has to do an
extra 180M of I/O.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Running a textconv filter can take a long time. It's
particularly bad for a large file which needs to be spooled
to disk, but even for small files, the fork+exec overhead
can add up for something like "git log -p".

This patch uses the notes-cache mechanism to keep a fast
cache of textconv output. Caches are stored in
refs/notes/textconv/$x, where $x is the userdiff driver
defined in gitattributes.

Caching is enabled only if diff.$x.cachetextconv is true.

In my test repo, on a commit with 45 jpg and avi files
changed and a textconv to show their exif tags:

  [before]
  $ time git show >/dev/null
  real    0m13.724s
  user    0m12.057s
  sys     0m1.624s

  [after, first run]
  $ git config diff.mfo.cachetextconv true
  $ time git show >/dev/null
  real    0m14.252s
  user    0m12.197s
  sys     0m1.800s

  [after, subsequent runs]
  $ time git show >/dev/null
  real    0m0.352s
  user    0m0.148s
  sys     0m0.200s

So for a slight (3.8%) cost on the first run, we achieve an
almost 40x speed up on subsequent runs.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This patch adds a fill_textconv wrapper, which centralizes
some minor logic like error checking and handling the case
of no-textconv.

In addition to dropping the number of lines, this will make
it easier in future patches to handle multiple types of
textconv.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We correctly free() for the normal diff case, but leak for
rewrite diffs.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

To make the code simpler, run_textconv lumps all of its
error checking into one conditional. However, the
short-circuit means that an error in reading will prevent us
from calling finish_command, leaving a zombie child.
Clean up properly after errors.
Based-on-work-by: NJeff King <peff@peff.net>
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Testing if the output "new commits" should appear in the long format of
"git status" is done by comparing the hashes of the diffpair. This always
resulted in printing "new commits" for submodules that contained untracked
or modified content, even if they did not contain new commits. The reason
was that match_stat_with_submodule() did set the "changed" flag for dirty
submodules, resulting in two->sha1 being set to the null_sha1 at the call
sites, which indicates that new commits are present. This is changed so
that when no new commits are present, the same object names are in the
sha1 field for both sides of the filepair, and the working tree side will
have the "dirty_submodule" flag set when appropriate. For a submodule to
be seen as modified even when it just has a dirty work tree, some
conditions had to be extended to also check for the "dirty_submodule"
flag.

Unfortunately the test case that should have found this bug had been
changed incorrectly too. It is fixed and extended to test for other
combinations too.
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Moving duplicated code into the new function match_stat_with_submodule().
Replacing the implicit activation of detailed checks for the dirtiness of
submodules when DIFF_FORMAT_PATCH was selected with explicitly setting
the recently added DIFF_OPT_DIRTY_SUBMODULES option in diff_setup_done().
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Make git-branch, git-show-branch, git-grep, and all the diff-based
programs accept an optional argument <when> for --color.  The argument
is a colorbool: "always", "never", or "auto".  If no argument is given,
"always" is used;  --no-color is an alias for --color=never.  This makes
the command-line interface consistent with other GNU tools, such as `ls'
and `grep', and with the git-config color options.  Note that, without
an argument, --color and --no-color work exactly as before.

To implement this, two internal changes were made:

1. Allow the first argument of git_config_colorbool() to be NULL,
   in which case it returns -1 if the argument isn't "always", "never",
   or "auto".

2. Add OPT_COLOR_FLAG(), OPT__COLOR(), and parse_opt_color_flag_cb()
   to the option parsing library.  The callback uses
   git_config_colorbool(), so color.h is now a dependency
   of parse-options.c.
Signed-off-by: NMark Lodato <lodatom@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The option -w tells the diff machinery to inspect the contents to set the
exit status, instead of checking the blob object level difference alone.
However, --quiet tells the diff machinery not to look at the contents, which
means DIFF_FROM_CONTENTS has no chance to inspect the change.

Work it around by calling diff_flush_patch() with output sent to /dev/null.
Signed-off-by: NLarry D'Anna <larry@elder-gods.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The return value from fopen wasn't being checked.
Signed-off-by: NLarry D'Anna <larry@elder-gods.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>