[v3,04/27] format-patch: don't leak "extra_headers" or "ref_message_ids"

Commit Message

Ævar Arnfjörð Bjarmason March 25, 2022, 5:18 p.m. UTC

Fix two memory leaks in "struct rev_info" by freeing that memory in
cmd_format_patch(). These two are unusual special-cases in being in
the "struct rev_info", but not being "owned" by the code in
revision.c. I.e. they're members of the struct so that this code in
"builtin/log.c" can pass information code in log-tree.c.

See 20ff06805c6 (format-patch: resurrect extra headers from config,
2006-06-02) and d1566f7883f (git-format-patch: Make the second and
subsequent mails replies to the first, 2006-07-14) for the initial
introduction of "extra_headers" and "ref_message_ids".

We can count on repo_init_revisions() memset()-ing this data to 0
however, so we can count on it being either NULL or something we
allocated. In the case of "extra_headers" let's add a local "char *"
variable to hold it, to avoid the eventual cast from "const char *"
when we free() it.

Signed-off-by: Ævar Arnfjörð Bjarmason <[e-mail]>
---
 builtin/log.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Patch

diff --git a/builtin/log.c b/builtin/log.c
index 634dc782cce..6f9928fabfe 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1747,6 +1747,7 @@  int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	struct commit *commit;
 	struct commit **list = NULL;
 	struct rev_info rev;
+	char *to_free = NULL;
 	struct setup_revision_opt s_r_opt;
 	int nr = 0, total, i;
 	int use_stdout = 0;
@@ -1947,7 +1948,7 @@  int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		strbuf_addch(&buf, '\n');
 	}
 
-	rev.extra_headers = strbuf_detach(&buf, NULL);
+	rev.extra_headers = to_free = strbuf_detach(&buf, NULL);
 
 	if (from) {
 		if (split_ident_line(&rev.from_ident, from, strlen(from)))
@@ -2284,6 +2285,10 @@  int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	strbuf_release(&rdiff1);
 	strbuf_release(&rdiff2);
 	strbuf_release(&rdiff_title);
+	free(to_free);
+	if (rev.ref_message_ids)
+		string_list_clear(rev.ref_message_ids, 0);
+	free(rev.ref_message_ids);
 	UNLEAK(rev);
 	return 0;
 }