unparse_commit(): defensive programming

dscho · gitster · commit 886dbcf95001 · 2025-05-15T13:45:59.000-07:00
CodeQL points out that `lookup_commit()` can return NULL values.

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/commit.c b/commit.c
@@ -188,7 +188,7 @@ void unparse_commit(struct repository *r, const struct object_id *oid)
 {
 	struct commit *c = lookup_commit(r, oid);
 
-	if (!c->object.parsed)
+	if (!c || !c->object.parsed)
 		return;
 	free_commit_list(c->parents);
 	c->parents = NULL;

Original file line number	Diff line number	Diff line change
`@@ -188,7 +188,7 @@ void unparse_commit(struct repository r, const struct object_id oid)`
`188`	`188`	`{`
`189`	`189`	`struct commit *c = lookup_commit(r, oid);`
`190`	`190`
`191`		`- if (!c->object.parsed)`
	`191`	`+ if (!c \|\| !c->object.parsed)`
`192`	`192`	`return;`
`193`	`193`	`free_commit_list(c->parents);`
`194`	`194`	`c->parents = NULL;`