Hi Ævar
On 31/03/2022 02:11, Ævar Arnfjörð Bjarmason wrote:
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.
I'm not sure that I necessarily agree that these are owned by
builtin/log.c. For rev.extra_headers it is set in builtin/log.c but
never used there which makes me think we are transferring ownership to
struct rev_info. For ref_message_ids it is less clear cut but having it
owned by struct rev_info and freeing it in release_revisions() would
make things clearer I think. Having some members owned by struct
rev_info but others allocated and freed by other code is confusing and
is likely to lead to memory errors. I don't think struct rev_info is
borrowing a reference to these items as they are being allocated for
it's exclusive use.
Best Wishes
Phillip
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 <avarab@xxxxxxxxx>
---
builtin/log.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
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;
}
