Merge branch 'sp/fetch-fix'

* sp/fetch-fix:
  git-fetch: avoid local fetching from alternate (again)
  rev-list: Introduce --quiet to avoid /dev/null redirects
  run-command: Support sending stderr to /dev/null
  git-fetch: Always fetch tags if the object they reference exists

Author: gitster

Documentation/git-rev-list.txt

@@ -20,6 +20,7 @@ SYNOPSIS
 	     [ \--not ]
 	     [ \--all ]
 	     [ \--stdin ]
+	     [ \--quiet ]
 	     [ \--topo-order ]
 	     [ \--parents ]
 	     [ \--timestamp ]
@@ -270,6 +271,14 @@ limiting may be applied.
 	In addition to the '<commit>' listed on the command
 	line, read them from the standard input.
 
+--quiet::
+
+	Don't print anything to standard output.  This form of
+	git-rev-list is primarly meant to allow the caller to
+	test the exit status to see if a range of objects is fully
+	connected (or not).  It is faster than redirecting stdout
+	to /dev/null as the output does not have to be formatted.
+
 --cherry-pick::
 
 	Omit any commit that introduces the same change as

builtin-fetch.c

@@ -8,10 +8,12 @@
 #include "path-list.h"
 #include "remote.h"
 #include "transport.h"
+#include "run-command.h"
 
 static const char fetch_usage[] = "git-fetch [-a | --append] [--upload-pack <upload-pack>] [-f | --force] [--no-tags] [-t | --tags] [-k | --keep] [-u | --update-head-ok] [--depth <depth>] [-v | --verbose] [<repository> <refspec>...]";
 
 static int append, force, tags, no_tags, update_head_ok, verbose, quiet;
+static const char *depth;
 static char *default_rla = NULL;
 static struct transport *transport;
 
@@ -335,9 +337,72 @@ static void store_updated_refs(const char *url, struct ref *ref_map)
 	fclose(fp);
 }
 
+/*
+ * We would want to bypass the object transfer altogether if
+ * everything we are going to fetch already exists and connected
+ * locally.
+ *
+ * The refs we are going to fetch are in to_fetch (nr_heads in
+ * total).  If running
+ *
+ *  $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
+ *
+ * does not error out, that means everything reachable from the
+ * refs we are going to fetch exists and is connected to some of
+ * our existing refs.
+ */
+static int quickfetch(struct ref *ref_map)
+{
+	struct child_process revlist;
+	struct ref *ref;
+	char **argv;
+	int i, err;
+
+	/*
+	 * If we are deepening a shallow clone we already have these
+	 * objects reachable.  Running rev-list here will return with
+	 * a good (0) exit status and we'll bypass the fetch that we
+	 * really need to perform.  Claiming failure now will ensure
+	 * we perform the network exchange to deepen our history.
+	 */
+	if (depth)
+		return -1;
+
+	for (i = 0, ref = ref_map; ref; ref = ref->next)
+		i++;
+	if (!i)
+		return 0;
+
+	argv = xmalloc(sizeof(*argv) * (i + 6));
+	i = 0;
+	argv[i++] = xstrdup("rev-list");
+	argv[i++] = xstrdup("--quiet");
+	argv[i++] = xstrdup("--objects");
+	for (ref = ref_map; ref; ref = ref->next)
+		argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
+	argv[i++] = xstrdup("--not");
+	argv[i++] = xstrdup("--all");
+	argv[i++] = NULL;
+
+	memset(&revlist, 0, sizeof(revlist));
+	revlist.argv = (const char**)argv;
+	revlist.git_cmd = 1;
+	revlist.no_stdin = 1;
+	revlist.no_stdout = 1;
+	revlist.no_stderr = 1;
+	err = run_command(&revlist);
+
+	for (i = 0; argv[i]; i++)
+		free(argv[i]);
+	free(argv);
+	return err;
+}
+
 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 {
-	int ret = transport_fetch_refs(transport, ref_map);
+	int ret = quickfetch(ref_map);
+	if (ret)
+		ret = transport_fetch_refs(transport, ref_map);
 	if (!ret)
 		store_updated_refs(transport->url, ref_map);
 	transport_unlock_pack(transport);
@@ -389,7 +454,7 @@ static struct ref *find_non_local_tags(struct transport *transport,
 
 		if (!path_list_has_path(&existing_refs, ref_name) &&
 		    !path_list_has_path(&new_refs, ref_name) &&
-		    lookup_object(ref->old_sha1)) {
+		    has_sha1_file(ref->old_sha1)) {
 			path_list_insert(ref_name, &new_refs);
 
 			rm = alloc_ref(strlen(ref_name) + 1);
@@ -473,7 +538,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	static const char **refs = NULL;
 	int ref_nr = 0;
 	int cmd_len = 0;
-	const char *depth = NULL, *upload_pack = NULL;
+	const char *upload_pack = NULL;
 	int keep = 0;
 
 	for (i = 1; i < argc; i++) {

builtin-rev-list.c

@@ -26,6 +26,7 @@ static const char rev_list_usage[] =
 "    --remove-empty\n"
 "    --all\n"
 "    --stdin\n"
+"    --quiet\n"
 "  ordering output:\n"
 "    --topo-order\n"
 "    --date-order\n"
@@ -50,6 +51,7 @@ static int show_timestamp;
 static int hdr_termination;
 static const char *header_prefix;
 
+static void finish_commit(struct commit *commit);
 static void show_commit(struct commit *commit)
 {
 	if (show_timestamp)
@@ -93,6 +95,11 @@ static void show_commit(struct commit *commit)
 		strbuf_release(&buf);
 	}
 	maybe_flush_or_die(stdout, "stdout");
+	finish_commit(commit);
+}
+
+static void finish_commit(struct commit *commit)
+{
 	if (commit->parents) {
 		free_commit_list(commit->parents);
 		commit->parents = NULL;
@@ -101,16 +108,20 @@ static void show_commit(struct commit *commit)
 	commit->buffer = NULL;
 }
 
+static void finish_object(struct object_array_entry *p)
+{
+	if (p->item->type == OBJ_BLOB && !has_sha1_file(p->item->sha1))
+		die("missing blob object '%s'", sha1_to_hex(p->item->sha1));
+}
+
 static void show_object(struct object_array_entry *p)
 {
 	/* An object with name "foo\n0000000..." can be used to
 	 * confuse downstream git-pack-objects very badly.
 	 */
 	const char *ep = strchr(p->name, '\n');
 
-	if (p->item->type == OBJ_BLOB && !has_sha1_file(p->item->sha1))
-		die("missing blob object '%s'", sha1_to_hex(p->item->sha1));
-
+	finish_object(p);
 	if (ep) {
 		printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
 		       (int) (ep - p->name),
@@ -527,6 +538,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	int read_from_stdin = 0;
 	int bisect_show_vars = 0;
 	int bisect_find_all = 0;
+	int quiet = 0;
 
 	git_config(git_default_config);
 	init_revisions(&revs, prefix);
@@ -565,6 +577,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			read_revisions_from_stdin(&revs);
 			continue;
 		}
+		if (!strcmp(arg, "--quiet")) {
+			quiet = 1;
+			continue;
+		}
 		usage(rev_list_usage);
 
 	}
@@ -640,7 +656,9 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	traverse_commit_list(&revs, show_commit, show_object);
+	traverse_commit_list(&revs,
+		quiet ? finish_commit : show_commit,
+		quiet ? finish_object : show_object);
 
 	return 0;
 }

run-command.c

@@ -41,7 +41,7 @@ int start_command(struct child_process *cmd)
 		cmd->close_out = 1;
 	}
 
-	need_err = cmd->err < 0;
+	need_err = !cmd->no_stderr && cmd->err < 0;
 	if (need_err) {
 		if (pipe(fderr) < 0) {
 			if (need_in)
@@ -87,7 +87,9 @@ int start_command(struct child_process *cmd)
 			close(cmd->out);
 		}
 
-		if (need_err) {
+		if (cmd->no_stderr)
+			dup_devnull(2);
+		else if (need_err) {
 			dup2(fderr[1], 2);
 			close_pair(fderr);
 		}

run-command.h

@@ -23,6 +23,7 @@ struct child_process {
 	unsigned close_out:1;
 	unsigned no_stdin:1;
 	unsigned no_stdout:1;
+	unsigned no_stderr:1;
 	unsigned git_cmd:1; /* if this is to be git sub-command */
 	unsigned stdout_to_stderr:1;
 };

t/t5502-quickfetch.sh

@@ -86,4 +86,37 @@ test_expect_success 'quickfetch should not leave a corrupted repository' '
 
 '
 
+test_expect_success 'quickfetch should not copy from alternate' '
+
+	(
+		mkdir quickclone &&
+		cd quickclone &&
+		git init-db &&
+		(cd ../.git/objects && pwd) >.git/objects/info/alternates &&
+		git remote add origin .. &&
+		git fetch -k -k
+	) &&
+	obj_cnt=$( (
+		cd quickclone &&
+		git count-objects | sed -e "s/ *objects,.*//"
+	) ) &&
+	pck_cnt=$( (
+		cd quickclone &&
+		git count-objects -v | sed -n -e "/packs:/{
+				s/packs://
+				p
+				q
+			}"
+	) ) &&
+	origin_master=$( (
+		cd quickclone &&
+		git rev-parse origin/master
+	) ) &&
+	echo "loose objects: $obj_cnt, packfiles: $pck_cnt" &&
+	test $obj_cnt -eq 0 &&
+	test $pck_cnt -eq 0 &&
+	test z$origin_master = z$(git rev-parse master)
+
+'
+
 test_done