Merge branch 'jt/lazy-fetch'

Updates to on-demand fetching code in lazily cloned repositories.

* jt/lazy-fetch:
  fetch: no FETCH_HEAD display if --no-write-fetch-head
  fetch-pack: remove no_dependents code
  promisor-remote: lazy-fetch objects in subprocess
  fetch-pack: do not lazy-fetch during ref iteration
  fetch: only populate existing_refs if needed
  fetch: avoid reading submodule config until needed
  fetch: allow refspecs specified through stdin
  negotiator/noop: add noop fetch negotiator

builtin/fetch.c

@@ -80,6 +80,7 @@ static struct list_objects_filter_options filter_options;
 static struct string_list server_options = STRING_LIST_INIT_DUP;
 static struct string_list negotiation_tip = STRING_LIST_INIT_NODUP;
 static int fetch_write_commit_graph = -1;
+static int stdin_refspecs = 0;
 
 static int git_fetch_config(const char *k, const char *v, void *cb)
 {
@@ -205,6 +206,8 @@ static struct option builtin_fetch_options[] = {
 		 N_("check for forced-updates on all updated branches")),
 	OPT_BOOL(0, "write-commit-graph", &fetch_write_commit_graph,
 		 N_("write the commit-graph after fetching")),
+	OPT_BOOL(0, "stdin", &stdin_refspecs,
+		 N_("accept refspecs from stdin")),
 	OPT_END()
 };
 
@@ -442,6 +445,7 @@ static struct ref *get_ref_map(struct remote *remote,
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
 	struct hashmap existing_refs;
+	int existing_refs_populated = 0;
 
 	if (rs->nr) {
 		struct refspec *fetch_refspec;
@@ -535,15 +539,18 @@ static struct ref *get_ref_map(struct remote *remote,
 
 	ref_map = ref_remove_duplicates(ref_map);
 
-	refname_hash_init(&existing_refs);
-	for_each_ref(add_one_refname, &existing_refs);
-
 	for (rm = ref_map; rm; rm = rm->next) {
 		if (rm->peer_ref) {
 			const char *refname = rm->peer_ref->name;
 			struct refname_hash_entry *peer_item;
 			unsigned int hash = strhash(refname);
 
+			if (!existing_refs_populated) {
+				refname_hash_init(&existing_refs);
+				for_each_ref(add_one_refname, &existing_refs);
+				existing_refs_populated = 1;
+			}
+
 			peer_item = hashmap_get_entry_from_hash(&existing_refs,
 						hash, refname,
 						struct refname_hash_entry, ent);
@@ -553,7 +560,8 @@ static struct ref *get_ref_map(struct remote *remote,
 			}
 		}
 	}
-	hashmap_free_entries(&existing_refs, struct refname_hash_entry, ent);
+	if (existing_refs_populated)
+		hashmap_free_entries(&existing_refs, struct refname_hash_entry, ent);
 
 	return ref_map;
 }
@@ -1015,11 +1023,17 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 				rc |= update_local_ref(ref, what, rm, &note,
 						       summary_width);
 				free(ref);
-			} else
+			} else if (write_fetch_head || dry_run) {
+				/*
+				 * Display fetches written to FETCH_HEAD (or
+				 * would be written to FETCH_HEAD, if --dry-run
+				 * is set).
+				 */
 				format_display(&note, '*',
 					       *kind ? kind : "branch", NULL,
 					       *what ? what : "HEAD",
 					       "FETCH_HEAD", summary_width);
+			}
 			if (note.len) {
 				if (verbosity >= 0 && !shown_url) {
 					fprintf(stderr, _("From %.*s\n"),
@@ -1680,7 +1694,8 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 	return;
 }
 
-static int fetch_one(struct remote *remote, int argc, const char **argv, int prune_tags_ok)
+static int fetch_one(struct remote *remote, int argc, const char **argv,
+		     int prune_tags_ok, int use_stdin_refspecs)
 {
 	struct refspec rs = REFSPEC_INIT_FETCH;
 	int i;
@@ -1737,6 +1752,13 @@ static int fetch_one(struct remote *remote, int argc, const char **argv, int pru
 		}
 	}
 
+	if (use_stdin_refspecs) {
+		struct strbuf line = STRBUF_INIT;
+		while (strbuf_getline_lf(&line, stdin) != EOF)
+			refspec_append(&rs, line.buf);
+		strbuf_release(&line);
+	}
+
 	if (server_options.nr)
 		gtransport->server_options = &server_options;
 
@@ -1771,12 +1793,18 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 		free(anon);
 	}
 
-	fetch_config_from_gitmodules(&submodule_fetch_jobs_config,
-				     &recurse_submodules);
 	git_config(git_fetch_config, NULL);
 
 	argc = parse_options(argc, argv, prefix,
 			     builtin_fetch_options, builtin_fetch_usage, 0);
+	if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
+		int *sfjc = submodule_fetch_jobs_config == -1
+			    ? &submodule_fetch_jobs_config : NULL;
+		int *rs = recurse_submodules == RECURSE_SUBMODULES_DEFAULT
+			  ? &recurse_submodules : NULL;
+
+		fetch_config_from_gitmodules(sfjc, rs);
+	}
 
 	if (deepen_relative) {
 		if (deepen_relative < 0)
@@ -1837,7 +1865,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	if (remote) {
 		if (filter_options.choice || has_promisor_remote())
 			fetch_one_setup_partial(remote);
-		result = fetch_one(remote, argc, argv, prune_tags_ok);
+		result = fetch_one(remote, argc, argv, prune_tags_ok, stdin_refspecs);
 	} else {
 		int max_children = max_jobs;
 
@@ -1845,6 +1873,10 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 			die(_("--filter can only be used with the remote "
 			      "configured in extensions.partialclone"));
 
+		if (stdin_refspecs)
+			die(_("--stdin can only be used when fetching "
+			      "from one remote"));
+
 		if (max_children < 0)
 			max_children = fetch_parallel_config;