Merge branch 'jc/checkout-reflog-fix' into maint

* jc/checkout-reflog-fix:
  checkout: do not write bogus reflog entry out

Author: gitster

builtin/checkout.c

@@ -715,10 +715,12 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 	unsigned char rev[20];
 	int flag;
 	memset(&old, 0, sizeof(old));
-	old.path = resolve_ref("HEAD", rev, 0, &flag);
+	old.path = xstrdup(resolve_ref("HEAD", rev, 0, &flag));
 	old.commit = lookup_commit_reference_gently(rev, 1);
-	if (!(flag & REF_ISSYMREF))
+	if (!(flag & REF_ISSYMREF)) {
+		free((char *)old.path);
 		old.path = NULL;
+	}
 
 	if (old.path && !prefixcmp(old.path, "refs/heads/"))
 		old.name = old.path + strlen("refs/heads/");
@@ -741,6 +743,7 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 	update_refs_for_switch(opts, &old, new);
 
 	ret = post_checkout_hook(old.commit, new->commit, 1);
+	free((char *)old.path);
 	return ret || opts->writeout_error;
 }