Merge 'remote-hg-prerequisites' into HEAD

These fixes were necessary for Sverre Rabbelier's remote-hg to work,
but for some magic reason they are not necessary for the current
remote-hg. Makes you wonder how that one gets away with it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

builtin/clone.c

@@ -1166,7 +1166,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			}
 
 		if (!is_local && !complete_refs_before_fetch)
-			transport_fetch_refs(transport, mapped_refs);
+			if (transport_fetch_refs(transport, mapped_refs))
+				die(_("could not fetch refs from %s"),
+				    transport->url);
 
 		remote_head = find_ref_by_name(refs, "HEAD");
 		remote_head_points_at =

builtin/fast-export.c

@@ -874,9 +874,20 @@ static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 	}
 }
 
+static void handle_reset(const char *name, struct object *object)
+{
+	int mark = get_object_mark(object);
+
+	if (mark)
+		printf("reset %s\nfrom :%d\n\n", name,
+		       get_object_mark(object));
+	else
+		printf("reset %s\nfrom %s\n\n", name,
+		       oid_to_hex(&object->oid));
+}
+
 static void handle_tags_and_duplicates(void)
 {
-	struct commit *commit;
 	int i;
 
 	for (i = extra_refs.nr - 1; i >= 0; i--) {
@@ -890,9 +901,7 @@ static void handle_tags_and_duplicates(void)
 			if (anonymize)
 				name = anonymize_refname(name);
 			/* create refs pointing to already seen commits */
-			commit = (struct commit *)object;
-			printf("reset %s\nfrom :%d\n\n", name,
-			       get_object_mark(&commit->object));
+			handle_reset(name, object);
 			show_progress();
 			break;
 		}

t/t5801-remote-helpers.sh

@@ -228,7 +228,7 @@ test_expect_success 'push update refs failure' '
 	echo "update fail" >>file &&
 	git commit -a -m "update fail" &&
 	git rev-parse --verify testgit/origin/heads/update >expect &&
-	test_expect_code 1 env GIT_REMOTE_TESTGIT_FAILURE="non-fast forward" \
+	test_must_fail env GIT_REMOTE_TESTGIT_FAILURE="non-fast forward" \
 		git push origin update &&
 	git rev-parse --verify testgit/origin/heads/update >actual &&
 	test_cmp expect actual

t/t9350-fast-export.sh

@@ -556,4 +556,15 @@ test_expect_success 'merge commit gets exported with --import-marks' '
 	)
 '
 
+cat > expected << EOF
+reset refs/heads/master
+from $(git rev-parse master)
+
+EOF
+
+test_expect_failure 'refs are updated even if no commits need to be exported' '
+	git fast-export master..master > actual &&
+	test_cmp expected actual
+'
+
 test_done

transport-helper.c

@@ -16,6 +16,8 @@
 #include "protocol.h"
 
 static int debug;
+/* TODO: put somewhere sensible, e.g. git_transport_options? */
+static int auto_gc = 1;
 
 struct helper_data {
 	const char *name;
@@ -460,10 +462,25 @@ static int get_exporter(struct transport *transport,
 	for (i = 0; i < revlist_args->nr; i++)
 		argv_array_push(&fastexport->args, revlist_args->items[i].string);
 
+	argv_array_push(&fastexport->args, "--");
+
 	fastexport->git_cmd = 1;
 	return start_command(fastexport);
 }
 
+static void check_helper_status(struct helper_data *data)
+{
+	int pid, status;
+
+	pid = waitpid(data->helper->pid, &status, WNOHANG);
+	if (pid < 0)
+		die("Could not retrieve status of remote helper '%s'",
+		    data->name);
+	if (pid > 0 && WIFEXITED(status))
+		die("Remote helper '%s' died with %d",
+		    data->name, WEXITSTATUS(status));
+}
+
 static int fetch_with_import(struct transport *transport,
 			     int nr_heads, struct ref **to_fetch)
 {
@@ -500,6 +517,7 @@ static int fetch_with_import(struct transport *transport,
 
 	if (finish_command(&fastimport))
 		die(_("error while running fast-import"));
+	check_helper_status(data);
 
 	/*
 	 * The fast-import stream of a remote helper that advertises
@@ -533,6 +551,12 @@ static int fetch_with_import(struct transport *transport,
 		}
 	}
 	strbuf_release(&buf);
+	if (auto_gc) {
+		const char *argv_gc_auto[] = {
+			"gc", "--auto", "--quiet", NULL,
+		};
+		run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
+	}
 	return 0;
 }
 
@@ -987,6 +1011,7 @@ static int push_refs_with_export(struct transport *transport,
 
 	if (finish_command(&exporter))
 		die(_("error while running fast-export"));
+	check_helper_status(data);
 	if (push_update_refs_status(data, remote_refs, flags))
 		return 1;