@matheusbsbs / matheus-bagliano / commits / f34b205f6c

diff: do not quit early on stat-dirty files

When QUICK is set (i.e. with --quiet) we try to do as little work as possible, stopping after seeing the first change. stat-dirty is considered a "change" but it may turn out not, if no actual content is changed. The actual content test is performed too late in the process and the shortcut may be taken prematurely, leading to incorrect return code. Assume we do "git diff --quiet". If we have a stat-dirty file "a" and a really dirty file "b". We break the loop in run_diff_files() and stop after "a" because we have got a "change". Later in diffcore_skip_stat_unmatch() we find out "a" is actually not changed. But there's nothing else in the diff queue, we incorrectly declare "no change", ignoring the fact that "b" is changed. This also happens to "git diff --quiet HEAD" when it hits diff_can_quit_early() in oneway_diff(). This patch does the content test earlier in order to keep going if "a" is unchanged. The test result is cached so that when diffcore_skip_stat_unmatch() is done in the end, we spend no cycles on re-testing "a". Reported-by: IWAMOTO Toshihiro <iwamoto@valinux.co.jp> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Nguyễn Thái Ngọc Duy committed Jan 25, 2014 at 13:46 UTC f34b205f6cc2c78cbed03a1582422cb59e36f729

3 files changed +25 -5

diff.c

+17 -5

@@ -4594,6 +4594,11 @@ static int diff_filespec_is_identical(struct diff_filespec *one,

4594

4595 static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)

4596 {

4597 + if (p->done_skip_stat_unmatch)

4598 + return p->skip_stat_unmatch_result;

4599 +

4600 + p->done_skip_stat_unmatch = 1;

4601 + p->skip_stat_unmatch_result = 0;

4602 /*

4603 * 1. Entries that come from stat info dirtiness

4604 * always have both sides (iow, not create/delete),

@@ -4615,8 +4620,8 @@ static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)

4620 diff_populate_filespec(p->two, 1) ||

4621 (p->one->size != p->two->size) ||

4622 !diff_filespec_is_identical(p->one, p->two)) /* (2) */

4618 - return 1;

4619 - return 0;

4623 + p->skip_stat_unmatch_result = 1;

4624 + return p->skip_stat_unmatch_result;

4625 }

4626

4627 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)

@@ -4792,6 +4797,7 @@ void diff_change(struct diff_options *options,

4797 unsigned old_dirty_submodule, unsigned new_dirty_submodule)

4798 {

4799 struct diff_filespec *one, *two;

4800 + struct diff_filepair *p;

4801

4802 if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&

4803 is_submodule_ignored(concatpath, options))

@@ -4818,10 +4824,16 @@ void diff_change(struct diff_options *options,

4824 fill_filespec(two, new_sha1, new_sha1_valid, new_mode);

4825 one->dirty_submodule = old_dirty_submodule;

4826 two->dirty_submodule = new_dirty_submodule;

4827 + p = diff_queue(&diff_queued_diff, one, two);

4828

4822 - diff_queue(&diff_queued_diff, one, two);

4823 - if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))

4824 - DIFF_OPT_SET(options, HAS_CHANGES);

4829 + if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))

4830 + return;

4831 +

4832 + if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&

4833 + !diff_filespec_check_stat_unmatch(p))

4834 + return;

4835 +

4836 + DIFF_OPT_SET(options, HAS_CHANGES);

4837 }

4838

4839 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)

diffcore.h

@@ -70,6 +70,8 @@ struct diff_filepair {

70 unsigned broken_pair : 1;

71 unsigned renamed_pair : 1;

72 unsigned is_unmerged : 1;

73 + unsigned done_skip_stat_unmatch : 1;

74 + unsigned skip_stat_unmatch_result : 1;

75 };

76 #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)

t/t4035-diff-quiet.sh

@@ -148,4 +148,10 @@ test_expect_success 'git diff --ignore-all-space, both files outside repo' '

148 )

149 '

150

151 +test_expect_success 'git diff --quiet ignores stat-change only entries' '

152 + test-chmtime +10 a &&

153 + echo modified >>b &&

154 + test_expect_code 1 git diff --quiet

155 +'

156 +

157 test_done