From b2b5ad514d62ba26b3cfa65104d81c2d19552789 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Fri, 24 Oct 2025 13:08:53 -0400 Subject: diff: replace diff_options.dry_run flag with NULL file We introduced a dry_run flag to diff_options in b55e6d36eb (diff: ensure consistent diff behavior with ignore options, 2025-08-08), with the idea that the lower-level diff code could skip output when it is set. As we saw with the bugs fixed by 3ed5d8bd73 (diff: stop output garbled message in dry run mode, 2025-10-20), it is easy to miss spots. In the end, we located all of them by checking where diff_options.file is used. That suggests another possible approach: we can replace the dry_run boolean with a NULL pointer for "file", as we know that using "file" in dry_run mode would always be an error. This turns any missed spots from producing extra output[1] into a segfault. Which is less forgiving, but that is the point: this is indicative of a programming error, and complaining loudly and immediately is good. [1] We protect ourselves against garbled output as a separate step, courtesy of 623f7af284 (diff: restore redirection to /dev/null for diff_from_contents, 2025-10-17). So in that sense this patch can only introduce user-visible errors (since any "bugs" were going to /dev/null before), but the idea is to catch them rather than quietly send garbage to /dev/null. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- diff.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'diff.h') diff --git a/diff.h b/diff.h index 2fa256c3ef..31eedd5c0c 100644 --- a/diff.h +++ b/diff.h @@ -408,8 +408,6 @@ struct diff_options { #define COLOR_MOVED_WS_ERROR (1<<0) unsigned color_moved_ws_handling; - bool dry_run; - struct repository *repo; struct strmap *additional_path_headers; -- cgit v1.3