Merge branch 'jk/disable-commit-graph-during-upload-pack'

The "upload-pack" (the counterpart of "git fetch") needs to disable
commit-graph when responding to a shallow clone/fetch request, but
the way this was done made Git panic, which has been corrected.

* jk/disable-commit-graph-during-upload-pack:
  upload-pack: disable commit graph more gently for shallow traversal
  commit-graph: bump DIE_ON_LOAD check to actual load-time

1 files changed, 15 insertions, 3 deletions

diff --git a/commit-graph.c b/commit-graph.c
index 5da0e16d12..394908ba9b 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -468,14 +468,21 @@ static int prepare_commit_graph(struct repository *r)
 {
 	struct object_directory *odb;
 
-	if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
-		die("dying as requested by the '%s' variable on commit-graph load!",
-		    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
+	/*
+	 * This must come before the "already attempted?" check below, because
+	 * we want to disable even an already-loaded graph file.
+	 */
+	if (r->commit_graph_disabled)
+		return 0;
 
 	if (r->objects->commit_graph_attempted)
 		return !!r->objects->commit_graph;
 	r->objects->commit_graph_attempted = 1;
 
+	if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
+		die("dying as requested by the '%s' variable on commit-graph load!",
+		    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
+
 	prepare_repo_settings(r);
 
 	if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
@@ -2101,3 +2108,8 @@ void free_commit_graph(struct commit_graph *g)
 	free(g->filename);
 	free(g);
 }
+
+void disable_commit_graph(struct repository *r)
+{
+	r->commit_graph_disabled = 1;
+}