subtree: performance improvement for finding unexpected parent commits

diff --git a/commit-graph.c b/commit-graph.c
index ae6cabb4cda46a74d5f4f59bbf54a550361fd10f..7f4519ec3b1a6659551fc4ba792cbef151367a4e 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -213,8 +213,9 @@ static int prepare_commit_graph(struct repository *r)
                return !!r->objects->commit_graph;
        r->objects->commit_graph_attempted = 1;
 
-       if (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
-           !config_value)
+       if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
+           (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
+           !config_value))
                /*
                 * This repository is not configured to use commit graphs, so
                 * do not load one. (But report commit_graph_attempted anyway