On Wed, Aug 16, 2023 at 04:45:23PM -0700, Junio C Hamano wrote:
> To fix this, do two things:
>
> * The codepath to generate "--stat" output already calls the
> underlying xdiff machinery with appropriate options like "-w",
> but it did not update .found_changes bit. Fixing "--stat -w"
> combined with "--exit-code" thus becomes just the matter of
> adding these missing .found_changes assignment.
>
> * For generating "--name-only", "--name-status", etc., the code
> does not look into the contents of the blob objects at all. For
> now, extend the special case used for "-s -w --exit-code" to run
> a silent "--patch" computation to set the .found_changes bit
> correctly.
Nicely explained overall, but one hunk of the patch left me wondering...
> @@ -3828,6 +3830,11 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
> diffstat_consume, diffstat, &xpp, &xecfg))
> die("unable to generate diffstat for %s", one->path);
>
> + /* Do this before cancelling the no-op diffstat below */
> + if (diffstat->files[diffstat->nr - 1]->added ||
> + diffstat->files[diffstat->nr - 1]->deleted)
> + o->found_changes = 1;
> +
So this is checking whether any lines were added/deleted to see if the
stat was a noop. But what about non-content bits, like mode changes?
E.g., the tests below all fail (but would pass without "-w"):
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 1b944d77e4..54e56ad911 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -25,6 +25,14 @@ test_expect_success 'exit status with -w --name-only (different but equivalent)'
git diff -w --name-only --exit-code x
'
+test_expect_success 'exit status with -w --name-only (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --name-only --exit-code
+'
+
test_expect_success 'exit status with -w --raw (different)' '
echo foo >x &&
git add x &&
@@ -39,6 +47,14 @@ test_expect_success 'exit status with -w --raw (different but equivalent)' '
git diff -w --raw --exit-code x
'
+test_expect_success 'exit status with -w --raw (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --raw --exit-code
+'
+
test_expect_success 'exit status with -w --stat (different)' '
echo foo >x &&
git add x &&
@@ -53,6 +69,14 @@ test_expect_success 'exit status with -w --stat (different but equivalent)' '
git diff -w --stat --exit-code x
'
+test_expect_success 'exit status with -w --stat (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --stat --exit-code
+'
+
test_expect_success 'exit status with -w --shortstat (different)' '
echo foo >x &&
git add x &&
@@ -67,6 +91,14 @@ test_expect_success 'exit status with -w --shortstat (different but equivalent)'
git diff -w --shortstat --exit-code x
'
+test_expect_success 'exit status with -w --shortstat (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --shortstat --exit-code
+'
+
test_expect_success 'exit status with -w --quiet (different)' '
echo foo >x &&
git add x &&
@@ -81,6 +113,14 @@ test_expect_success 'exit status with -w --quiet (different but equivalent)' '
git diff -w --quiet --exit-code x
'
+test_expect_success 'exit status with -w --quiet (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --quiet --exit-code
+'
+
test_expect_success 'exit status with -w --summary (different)' '
echo foo >x &&
git add x &&
@@ -95,6 +135,14 @@ test_expect_success 'exit status with -w --summary (different but equivalent)' '
git diff -w --summary --exit-code x
'
+test_expect_success 'exit status with -w --summary (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w --summary --exit-code
+'
+
test_expect_success 'exit status with -w -s (different)' '
echo foo >x &&
git add x &&
@@ -109,6 +157,14 @@ test_expect_success 'exit status with -w -s (different but equivalent)' '
git diff -w -s --exit-code x
'
+test_expect_success 'exit status with -w -s (mode change)' '
+ test_when_finished "git reset" &&
+ echo foo >x &&
+ git add x &&
+ git update-index --chmod=+x x &&
+ test_expect_code 1 git diff -w -s --exit-code x
+'
+
test_expect_success "Ray Lehtiniemi's example" '
cat <<-\EOF >x &&
do {
For the diffstat case, I think we could check the mode here, but there
are other cases (e.g., adding or deleting an empty file). The code right
below the hunk I quoted seems to try to deal with that (the "cancelling
the no-op" your comment mentions). I'm not sure if we want something
like this:
diff --git a/diff.c b/diff.c
index 38b57b589f..1dbfdaeff0 100644
--- a/diff.c
+++ b/diff.c
@@ -3853,6 +3853,8 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
&& one->mode == two->mode) {
free_diffstat_file(file);
diffstat->nr--;
+ } else {
+ o->found_changes = 1;
}
}
}
but I haven't dug too far (and of course all of the other options also
need something similar to catch this case).
-Peff
