From 0e5a87e0422ff308641199d1afe94b58e1249bc0 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 17 Oct 2022 21:01:17 -0400 Subject: [PATCH] diffstat_consume(): assert non-zero length The callback interface for xdiff_emit_line_fn gives us a line/len pair, but diffstat_consume() never looks at "len". At first glance this seems like a bug that could cause us to read further than xdiff intends. But in practice, we read only the first character, and xdiff would never pass us an empty line. Let's add a run-time assertion that this is true, which clarifies our assumption and silences -Wunused-parameter. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- diff.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/diff.c b/diff.c index 648f6717a5..bba888a34a 100644 --- a/diff.c +++ b/diff.c @@ -2488,6 +2488,9 @@ static int diffstat_consume(void *priv, char *line, unsigned long len) struct diffstat_t *diffstat = priv; struct diffstat_file *x = diffstat->files[diffstat->nr - 1]; + if (!len) + BUG("xdiff fed us an empty line"); + if (line[0] == '+') x->added++; else if (line[0] == '-') -- 2.47.3