commit-graph: fix segfault on e.g. "git status"

[thirdparty/git.git] / commit-graph.c

diff --git a/commit-graph.c b/commit-graph.c
index 47e9be0a3aad883c17221b11c972b8376a70a555..f8201d888b9a26299b3c7b0eb7cc48ad546dd7f2 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -112,6 +112,36 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
        return ret;
 }
 
+static int verify_commit_graph_lite(struct commit_graph *g)
+{
+       /*
+        * Basic validation shared between parse_commit_graph()
+        * which'll be called every time the graph is used, and the
+        * much more expensive verify_commit_graph() used by
+        * "commit-graph verify".
+        *
+        * There should only be very basic checks here to ensure that
+        * we don't e.g. segfault in fill_commit_in_graph(), but
+        * because this is a very hot codepath nothing that e.g. loops
+        * over g->num_commits, or runs a checksum on the commit-graph
+        * itself.
+        */
+       if (!g->chunk_oid_fanout) {
+               error("commit-graph is missing the OID Fanout chunk");
+               return 1;
+       }
+       if (!g->chunk_oid_lookup) {
+               error("commit-graph is missing the OID Lookup chunk");
+               return 1;
+       }
+       if (!g->chunk_commit_data) {
+               error("commit-graph is missing the Commit Data chunk");
+               return 1;
+       }
+
+       return 0;
+}
+
 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                                        size_t graph_size)
 {
@@ -233,6 +263,9 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                last_chunk_offset = chunk_offset;
        }
 
+       if (verify_commit_graph_lite(graph))
+               return NULL;
+
        return graph;
 }
 
@@ -1089,15 +1122,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                return 1;
        }
 
-       verify_commit_graph_error = 0;
-
-       if (!g->chunk_oid_fanout)
-               graph_report("commit-graph is missing the OID Fanout chunk");
-       if (!g->chunk_oid_lookup)
-               graph_report("commit-graph is missing the OID Lookup chunk");
-       if (!g->chunk_commit_data)
-               graph_report("commit-graph is missing the Commit Data chunk");
-
+       verify_commit_graph_error = verify_commit_graph_lite(g);
        if (verify_commit_graph_error)
                return verify_commit_graph_error;