[PATCH 5/4] diff: simplify run_external_diff() quiet logic
- From
Jeff King <peff@peff.net>
- Date
- Oct 24, 2025, 17:25 UTC
- Message-ID
- <20251024172507.GA3081793@coredump.intra.peff.net>
- In-Reply-To
- <20251024170522.GA2344972@coredump.intra.peff.net>
We'd sometimes end up in run_external_diff() to do a dry-run diff (e.g., to find content-level changes for --quiet). We recognize this quiet mode by seeing the lack of DIFF_FORMAT_PATCH in the output format.
But since introducing an explicit dry-run check via 3ed5d8bd73 (diff: stop output garbled message in dry run mode, 2025-10-20), this logic can never trigger. We can only get to this function by calling diff_flush_patch(), and that comes from only two places:
1. A dry-run flush comes from diff_flush_patch_quietly(), which is
always in dry-run mode (so the other half of our "||" is true
anyway). 2. A regular flush comes from diff_flush_patch_all_file_pairs(),
which is only called when output_format has DIFF_FORMAT_PATCH in
it.So we can simplify our "quiet" condition to just checking dry-run mode (which used to be a specific flag, but recently became just a NULL "file" pointer). And since it's so simple, we can just do that inline. This makes the logic about o->file more obvious, since we handle the NULL and non-stdout cases next to each other.
Signed-off-by: Jeff King <peff@peff.net> --- Here's one more that I forgot to poke at before sending out the others.
diff.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/diff.c b/diff.c index 9169ccfaa9..a1961526c0 100644 --- a/diff.c +++ b/diff.c @@ -4423,7 +4423,6 @@ static void run_external_diff(const struct external_diff *pgm, { struct child_process cmd = CHILD_PROCESS_INIT; struct diff_queue_struct *q = &diff_queued_diff; - int quiet = !(o->output_format & DIFF_FORMAT_PATCH) || !o->file; int rc; /* @@ -4432,7 +4431,7 @@ static void run_external_diff(const struct external_diff *pgm, * external diff program lacks the ability to tell us whether * it's empty then we consider it non-empty without even asking. */ - if (!pgm->trust_exit_code && quiet) { + if (!pgm->trust_exit_code && !o->file) { o->found_changes = 1; return; } @@ -4457,7 +4456,7 @@ static void run_external_diff(const struct external_diff *pgm, diff_free_filespec_data(one); diff_free_filespec_data(two); cmd.use_shell = 1; - if (quiet) + if (!o->file) cmd.no_stdout = 1; else if (o->file != stdout) cmd.out = xdup(fileno(o->file));
-- 2.51.1.797.g1148beab57