Merge branch 'pt/promisor-lazy-fetch-no-recurse' into jch

* pt/promisor-lazy-fetch-no-recurse:
  promisor-remote: prevent lazy-fetch recursion in child fetch

promisor-remote.c

@@ -42,6 +42,13 @@ static int fetch_objects(struct repository *repo,
 	child.in = -1;
 	if (repo != the_repository)
 		prepare_other_repo_env(&child.env, repo->gitdir);
+	/*
+	 * Prevent the child's index-pack from recursing back into
+	 * fetch_objects() when resolving REF_DELTA bases it does not
+	 * have.  With noop negotiation the server should never need
+	 * to send such deltas, so a depth-2 fetch would not help.
+	 */
+	strvec_pushf(&child.env, "%s=1", NO_LAZY_FETCH_ENVIRONMENT);
 	strvec_pushl(&child.args, "-c", "fetch.negotiationAlgorithm=noop",
 		     "fetch", remote_name, "--no-tags",
 		     "--no-write-fetch-head", "--recurse-submodules=no",

t/t0411-clone-from-partial.sh

@@ -78,4 +78,30 @@ test_expect_success 'promisor lazy-fetching can be re-enabled' '
 	test_path_is_file script-executed
 '
 
+test_expect_success 'lazy-fetch child has GIT_NO_LAZY_FETCH=1' '
+	test_create_repo nolazy-server &&
+	test_commit -C nolazy-server foo &&
+	git -C nolazy-server repack -a -d --write-bitmap-index &&
+
+	git clone "file://$(pwd)/nolazy-server" nolazy-client &&
+	HASH=$(git -C nolazy-client rev-parse foo) &&
+	rm -rf nolazy-client/.git/objects/* &&
+
+	git -C nolazy-client config core.repositoryformatversion 1 &&
+	git -C nolazy-client config extensions.partialclone "origin" &&
+
+	# Install a reference-transaction hook to record the env var
+	# as seen by processes inside the child fetch.
+	test_hook -C nolazy-client reference-transaction <<-\EOF &&
+	echo "$GIT_NO_LAZY_FETCH" >>../env-in-child
+	EOF
+
+	rm -f env-in-child &&
+	git -C nolazy-client cat-file -p "$HASH" &&
+
+	# The hook runs inside the child fetch, which should have
+	# GIT_NO_LAZY_FETCH=1 in its environment.
+	grep "^1$" env-in-child
+'
+
 test_done