Merge branch 'ma/reduce-heads-leakfix' into maint

Leak fixes.

* ma/reduce-heads-leakfix:
reduce_heads: fix memory leaks
builtin/merge-base: free commit lists

diff --combined builtin/commit.c
index b2a6c7f100d82c4160c4bea6b4663af5459194cc,11c47401854fa4bfd8b75429f053882ff1c61551..be370f64a995804ec6b62e03f7c6940044e08e24
--- 1/builtin/commit.c
--- 2/builtin/commit.c
+++ b/builtin/commit.c
@@@ -1492,8 -1492,6 +1492,8 @@@ static void print_summary(const char *p
        diff_setup_done(&rev.diffopt);
  
        head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
 +      if (!head)
 +              die_errno(_("unable to resolve HEAD after creating commit"));
        if (!strcmp(head, "HEAD"))
                head = _("detached HEAD");
        else
@@@ -1730,7 -1728,7 +1730,7 @@@ int cmd_commit(int argc, const char **a
                                allow_fast_forward = 0;
                }
                if (allow_fast_forward)
-                       parents = reduce_heads(parents);
+                       reduce_heads_replace(&parents);
        } else {
                if (!reflog_msg)
                        reflog_msg = (whence == FROM_CHERRY_PICK)