From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Subject: [PATCH 01/12] diffstat_consume(): assert non-zero length
Date: Mon, 17 Oct 2022 21:01:17 -0400 [thread overview]
Message-ID: <Y0363eQnvcNkCG/O@coredump.intra.peff.net> (raw)
In-Reply-To: <Y036whEorZV0rOgB@coredump.intra.peff.net>
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 <peff@peff.net>
---
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] == '-')
--
2.38.0.371.g300879f34e
next prev parent reply other threads:[~2022-10-18 1:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 1:00 [PATCH 0/12] more unused-parameter fixes / annotations Jeff King
2022-10-18 1:01 ` Jeff King [this message]
2022-10-18 1:02 ` [PATCH 02/12] submodule--helper: drop unused argc from module_list_compute() Jeff King
2022-10-18 1:04 ` [PATCH 03/12] update-index: drop unused argc from do_reupdate() Jeff King
2022-10-18 1:05 ` [PATCH 04/12] mark unused parameters in trivial compat functions Jeff King
2022-10-18 1:05 ` [PATCH 05/12] object-file: mark unused parameters in hash_unknown functions Jeff King
2022-10-18 1:05 ` [PATCH 06/12] string-list: mark unused callback parameters Jeff King
2022-10-18 1:05 ` [PATCH 07/12] date: mark unused parameters in handler functions Jeff King
2022-10-18 1:08 ` [PATCH 08/12] apply: mark unused parameters in handlers Jeff King
2022-10-18 1:08 ` [PATCH 09/12] apply: mark unused parameters in noop error/warning routine Jeff King
2022-10-18 1:08 ` [PATCH 10/12] convert: mark unused parameter in null stream filter Jeff King
2022-10-18 1:09 ` [PATCH 11/12] diffcore-pickaxe: mark unused parameters in pickaxe functions Jeff King
2022-10-18 1:10 ` [PATCH 12/12] ll-merge: mark unused parameters in callbacks Jeff King
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