commit 579bd556f987d6059cca7f20219140dae23079f3
from: Stefan Sperling <stsp@stsp.name>
date: Sat Oct 24 13:18:03 2020 UTC

prevent a NULL dereference if 'got log -p' runs against a root commit

commit - eef9542c44a360aeec73151d75342f0559a590b4
commit + 579bd556f987d6059cca7f20219140dae23079f3
blob - 5bfcaac31178afc5018d764b995989379c1ccfe7
blob + 40ab964e77891970bf5fa1e069607c1aa4a6c250
--- got/got.c
+++ got/got.c
@@ -3297,10 +3297,12 @@ print_patch(struct got_commit_object *commit, struct g
 		err = got_object_id_str(&id_str2, obj_id2);
 		if (err)
 			goto done;
-		obj_id1 = got_object_commit_get_tree_id(pcommit);
-		err = got_object_id_str(&id_str1, obj_id1);
-		if (err)
-			goto done;
+		if (pcommit) {
+			obj_id1 = got_object_commit_get_tree_id(pcommit);
+			err = got_object_id_str(&id_str1, obj_id1);
+			if (err)
+				goto done;
+		}
 		printf("diff %s %s\n", id_str1 ? id_str1 : "/dev/null", id_str2);
 		err = diff_trees(obj_id1, obj_id2, "", diff_context, 0, repo);
 	}