The diff machinery has two ways to detect changes to set the exit code: Just comparing hashes and comparing blob contents. The latter is needed if certain changes have to be ignored, e.g. with --ignore-space-change or --ignore-matching-lines. It's enabled by the diff_options flag diff_from_contents. The code for handling binary files added by 1aaf69e669 (diff: shortcut for diff'ing two binary SHA-1 objects, 2014-08-16) always uses a quick hash-only comparison, even if the slow way is taken. We need it to report a hash difference as a change for the purpose of setting the exit code, though, but it never did. Fix that. d7b97b7185 (diff: let external diffs report that changes are uninteresting, 2024-06-09) set diff_from_contents if external diff programs are allowed. This is the default e.g. for git diff, and so that change exposed the inconsistency much more widely. Reported-by: Kohei Shibata <shiba200712@xxxxxxxxx> Signed-off-by: René Scharfe <l.s.r@xxxxxx> --- Thank you for the report! diff.c | 1 + t/t4017-diff-retval.sh | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/diff.c b/diff.c index 3be927b073..84a6bb0868 100644 --- a/diff.c +++ b/diff.c @@ -3675,6 +3675,7 @@ static void builtin_diff(const char *name_a, emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES, sb.buf, sb.len, 0); strbuf_release(&sb); + o->found_changes = 1; goto free_ab_and_return; } if (fill_mmfile(o->repo, &mf1, one) < 0 || diff --git a/t/t4017-diff-retval.sh b/t/t4017-diff-retval.sh index d644310e22..1cea73ef5a 100755 --- a/t/t4017-diff-retval.sh +++ b/t/t4017-diff-retval.sh @@ -145,6 +145,14 @@ test_expect_success 'option errors are not confused by --exit-code' ' for option in --exit-code --quiet do + test_expect_success "git diff $option returns 1 for changed binary file" " + test_when_finished 'rm -f .gitattributes' && + git reset --hard && + echo a binary >.gitattributes && + echo 2 >>a && + test_expect_code 1 git diff $option + " + test_expect_success "git diff $option returns 1 for copied file" " git reset --hard && cp a copy && -- 2.46.0
