Fix a possible null pointer dereference

lhchavez · lhchavez · commit 1e49f12793c4 · 2021-08-31T05:23:20.000-07:00
This change fixes a possible null pointer dereference if anything inside `git_commit_graph_writer_add_index_file` fails before the packfile being valid. https://scan6.coverity.com/reports.htm#v52218/p10377/fileInstanceId=122935896&defectInstanceId=32525576&mergedDefectId=1461634
diff --git a/src/commit_graph.c b/src/commit_graph.c
@@ -716,7 +716,8 @@ int git_commit_graph_writer_add_index_file(
 		goto cleanup;
 
 cleanup:
-	git_mwindow_put_pack(p);
+	if (p)
+		git_mwindow_put_pack(p);
 	git_odb_free(state.db);
 	return error;
 }

Original file line number	Diff line number	Diff line change
`@@ -716,7 +716,8 @@ int git_commit_graph_writer_add_index_file(`
`716`	`716`	`goto cleanup;`
`717`	`717`
`718`	`718`	`cleanup:`
`719`		`- git_mwindow_put_pack(p);`
	`719`	`+ if (p)`
	`720`	`+ git_mwindow_put_pack(p);`
`720`	`721`	`git_odb_free(state.db);`
`721`	`722`	`return error;`
`722`	`723`	`}`