commit-graph: verify commit date

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit-graph.c

@@ -986,6 +986,12 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
 				     oid_to_hex(&cur_oid),
 				     graph_commit->generation,
 				     max_generation + 1);
+
+		if (graph_commit->date != odb_commit->date)
+			graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
+				     oid_to_hex(&cur_oid),
+				     graph_commit->date,
+				     odb_commit->date);
 	}
 
 	return verify_commit_graph_error;

t/t5318-commit-graph.sh

@@ -273,6 +273,7 @@ GRAPH_BYTE_COMMIT_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN))
 GRAPH_BYTE_COMMIT_EXTRA_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 4))
 GRAPH_BYTE_COMMIT_WRONG_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 3))
 GRAPH_BYTE_COMMIT_GENERATION=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 11))
+GRAPH_BYTE_COMMIT_DATE=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 12))
 
 # usage: corrupt_graph_and_verify <position> <data> <string>
 # Manipulates the commit-graph file at the position
@@ -377,4 +378,9 @@ test_expect_success 'detect incorrect generation number' '
 		"non-zero generation number"
 '
 
+test_expect_success 'detect incorrect commit date' '
+	corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_DATE "\01" \
+		"commit date"
+'
+
 test_done