Merge branch 'jt/partial-clone-submodule-1'

Prepare the internals for lazily fetching objects in submodules
from their promisor remotes.

* jt/partial-clone-submodule-1:
  promisor-remote: teach lazy-fetch in any repo
  run-command: refactor subprocess env preparation
  submodule: refrain from filtering GIT_CONFIG_COUNT
  promisor-remote: support per-repository config
  repository: move global r_f_p_c to repo struct

run-command.c

@@ -1891,3 +1891,15 @@ int run_auto_maintenance(int quiet)
 
 	return run_command(&maint);
 }
+
+void prepare_other_repo_env(struct strvec *env_array, const char *new_git_dir)
+{
+	const char * const *var;
+
+	for (var = local_repo_env; *var; var++) {
+		if (strcmp(*var, CONFIG_DATA_ENVIRONMENT) &&
+		    strcmp(*var, CONFIG_COUNT_ENVIRONMENT))
+			strvec_push(env_array, *var);
+	}
+	strvec_pushf(env_array, "%s=%s", GIT_DIR_ENVIRONMENT, new_git_dir);
+}