commit-graph: verify generation number

diff --git a/commit-graph.c b/commit-graph.c
index 282cdb4aec654a875e529d94beb7c1970eba1573..de656ebbaff88d692fc26b3f8a57d3d8798070ba 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -244,6 +244,9 @@ static struct commit_list **insert_parent_or_die(struct commit_graph *g,
        struct commit *c;
        struct object_id oid;
 
+       if (pos >= g->num_commits)
+               die("invalid parent position %"PRIu64, pos);
+
        hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
        c = lookup_commit(&oid);
        if (!c)
@@ -843,10 +846,14 @@ static void graph_report(const char *fmt, ...)
        va_end(ap);
 }
 
+#define GENERATION_ZERO_EXISTS 1
+#define GENERATION_NUMBER_EXISTS 2
+
 int verify_commit_graph(struct repository *r, struct commit_graph *g)
 {
        uint32_t i, cur_fanout_pos = 0;
        struct object_id prev_oid, cur_oid;
+       int generation_zero = 0;
 
        if (!g) {
                graph_report("no commit-graph file loaded");
@@ -866,6 +873,8 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                return verify_commit_graph_error;
 
        for (i = 0; i < g->num_commits; i++) {
+               struct commit *graph_commit;
+
                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
 
                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
@@ -883,6 +892,11 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                                             cur_fanout_pos, fanout_value, i);
                        cur_fanout_pos++;
                }
+
+               graph_commit = lookup_commit(&cur_oid);
+               if (!parse_commit_in_graph_one(g, graph_commit))
+                       graph_report("failed to parse %s from commit-graph",
+                                    oid_to_hex(&cur_oid));
        }
 
        while (cur_fanout_pos < 256) {
@@ -899,16 +913,79 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                return verify_commit_graph_error;
 
        for (i = 0; i < g->num_commits; i++) {
-               struct commit *odb_commit;
+               struct commit *graph_commit, *odb_commit;
+               struct commit_list *graph_parents, *odb_parents;
+               uint32_t max_generation = 0;
 
                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
 
+               graph_commit = lookup_commit(&cur_oid);
                odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
                if (parse_commit_internal(odb_commit, 0, 0)) {
                        graph_report("failed to parse %s from object database",
                                     oid_to_hex(&cur_oid));
                        continue;
                }
+
+               if (oidcmp(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
+                          get_commit_tree_oid(odb_commit)))
+                       graph_report("root tree OID for commit %s in commit-graph is %s != %s",
+                                    oid_to_hex(&cur_oid),
+                                    oid_to_hex(get_commit_tree_oid(graph_commit)),
+                                    oid_to_hex(get_commit_tree_oid(odb_commit)));
+
+               graph_parents = graph_commit->parents;
+               odb_parents = odb_commit->parents;
+
+               while (graph_parents) {
+                       if (odb_parents == NULL) {
+                               graph_report("commit-graph parent list for commit %s is too long",
+                                            oid_to_hex(&cur_oid));
+                               break;
+                       }
+
+                       if (oidcmp(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
+                               graph_report("commit-graph parent for %s is %s != %s",
+                                            oid_to_hex(&cur_oid),
+                                            oid_to_hex(&graph_parents->item->object.oid),
+                                            oid_to_hex(&odb_parents->item->object.oid));
+
+                       if (graph_parents->item->generation > max_generation)
+                               max_generation = graph_parents->item->generation;
+
+                       graph_parents = graph_parents->next;
+                       odb_parents = odb_parents->next;
+               }
+
+               if (odb_parents != NULL)
+                       graph_report("commit-graph parent list for commit %s terminates early",
+                                    oid_to_hex(&cur_oid));
+
+               if (!graph_commit->generation) {
+                       if (generation_zero == GENERATION_NUMBER_EXISTS)
+                               graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
+                                            oid_to_hex(&cur_oid));
+                       generation_zero = GENERATION_ZERO_EXISTS;
+               } else if (generation_zero == GENERATION_ZERO_EXISTS)
+                       graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
+                                    oid_to_hex(&cur_oid));
+
+               if (generation_zero == GENERATION_ZERO_EXISTS)
+                       continue;
+
+               /*
+                * If one of our parents has generation GENERATION_NUMBER_MAX, then
+                * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
+                * extra logic in the following condition.
+                */
+               if (max_generation == GENERATION_NUMBER_MAX)
+                       max_generation--;
+
+               if (graph_commit->generation != max_generation + 1)
+                       graph_report("commit-graph generation for commit %s is %u != %u",
+                                    oid_to_hex(&cur_oid),
+                                    graph_commit->generation,
+                                    max_generation + 1);
        }
 
        return verify_commit_graph_error;