diff: teach --stat to ignore uninteresting modifications
When options such as --ignore-space-change are in use, files with
modifications can have no interesting textual changes worth showing. In
such cases, "git diff --stat" shows 0 lines of additions and deletions.
Teach "git diff --stat" not to show such a path in its output, which
would be more natural.
However, we don't want to prevent the display of all files that have 0
effective diffs since they could be the result of a rename, permission
change, or other similar operation that may still be of interest so we
special case additions and deletions as they are always interesting.
Signed-off-by: Matthew Rogers <mattr94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diff.c b/diff.c
index d24aaa3..810c513 100644
--- a/diff.c
+++ b/diff.c
@@ -3153,16 +3153,19 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
gather_dirstat(options, &dir, changed, "", 0);
}
+static void free_diffstat_file(struct diffstat_file *f)
+{
+ free(f->print_name);
+ free(f->name);
+ free(f->from_name);
+ free(f);
+}
+
void free_diffstat_info(struct diffstat_t *diffstat)
{
int i;
- for (i = 0; i < diffstat->nr; i++) {
- struct diffstat_file *f = diffstat->files[i];
- free(f->print_name);
- free(f->name);
- free(f->from_name);
- free(f);
- }
+ for (i = 0; i < diffstat->nr; i++)
+ free_diffstat_file(diffstat->files[i]);
free(diffstat->files);
}
@@ -3718,6 +3721,27 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
diffstat_consume, diffstat, &xpp, &xecfg))
die("unable to generate diffstat for %s", one->path);
+
+ if (DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two)) {
+ struct diffstat_file *file =
+ diffstat->files[diffstat->nr - 1];
+ /*
+ * Omit diffstats of modified files where nothing changed.
+ * Even if !same_contents, this might be the case due to
+ * ignoring whitespace changes, etc.
+ *
+ * But note that we special-case additions, deletions,
+ * renames, and mode changes as adding an empty file,
+ * for example is still of interest.
+ */
+ if ((p->status == DIFF_STATUS_MODIFIED)
+ && !file->added
+ && !file->deleted
+ && one->mode == two->mode) {
+ free_diffstat_file(file);
+ diffstat->nr--;
+ }
+ }
}
diff_free_filespec_data(one);
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 88d3026..8bdaa0a 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -789,7 +789,7 @@
git diff --check
'
-test_expect_success 'whitespace-only changes not reported' '
+test_expect_success 'whitespace-only changes not reported (diff)' '
git reset --hard &&
echo >x "hello world" &&
git add x &&
@@ -799,8 +799,42 @@
test_must_be_empty actual
'
-test_expect_success 'whitespace-only changes reported across renames' '
+test_expect_success 'whitespace-only changes not reported (diffstat)' '
+ # reuse state from previous test
+ git diff --stat -b >actual &&
+ test_must_be_empty actual
+'
+
+test_expect_success 'whitespace changes with modification reported (diffstat)' '
git reset --hard &&
+ echo >x "hello world" &&
+ git update-index --chmod=+x x &&
+ git diff --stat --cached -b >actual &&
+ cat <<-EOF >expect &&
+ x | 0
+ 1 file changed, 0 insertions(+), 0 deletions(-)
+ EOF
+ test_cmp expect actual
+'
+
+test_expect_success 'whitespace-only changes reported across renames (diffstat)' '
+ git reset --hard &&
+ for i in 1 2 3 4 5 6 7 8 9; do echo "$i$i$i$i$i$i"; done >x &&
+ git add x &&
+ git commit -m "base" &&
+ sed -e "5s/^/ /" x >z &&
+ git rm x &&
+ git add z &&
+ git diff -w -M --cached --stat >actual &&
+ cat <<-EOF >expect &&
+ x => z | 0
+ 1 file changed, 0 insertions(+), 0 deletions(-)
+ EOF
+ test_cmp expect actual
+'
+
+test_expect_success 'whitespace-only changes reported across renames' '
+ git reset --hard HEAD~1 &&
for i in 1 2 3 4 5 6 7 8 9; do echo "$i$i$i$i$i$i"; done >x &&
git add x &&
hash_x=$(git hash-object x) &&
