From 1cf3d5db9bd11514465d3692216211315f0dc82c Mon Sep 17 00:00:00 2001 From: Matthew Rogers Date: Thu, 20 Aug 2020 00:41:32 +0000 Subject: [PATCH] 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 Signed-off-by: Junio C Hamano --- diff.c | 38 +++++++++++++++++++++++++++++++------- t/t4015-diff-whitespace.sh | 38 ++++++++++++++++++++++++++++++++++++-- 2 files changed, 67 insertions(+), 9 deletions(-) diff --git a/diff.c b/diff.c index d24aaa3047..810c513995 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 88d3026894..8bdaa0a693 100755 --- a/t/t4015-diff-whitespace.sh +++ b/t/t4015-diff-whitespace.sh @@ -789,7 +789,7 @@ test_expect_success 'checkdiff allows new blank lines' ' 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_expect_success 'whitespace-only changes not reported' ' 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) &&