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 <[email protected]>

t/t5801-remote-helpers.sh

@@ -262,7 +262,7 @@ 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

@@ -801,4 +801,15 @@ test_expect_success 'fast-export handles --end-of-options' '
 	test_cmp expect actual
 '
 
+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

@@ -22,6 +22,8 @@
 #include "packfile.h"
 
 static int debug;
+/* TODO: put somewhere sensible, e.g. git_transport_options? */
+static int auto_gc = 1;
 
 struct helper_data {
 	char *name;
@@ -499,10 +501,25 @@ static int get_exporter(struct transport *transport,
 	for (size_t i = 0; i < revlist_args->nr; i++)
 		strvec_push(&fastexport->args, revlist_args->items[i].string);
 
+	strvec_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)
 {
@@ -539,6 +556,7 @@ 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
@@ -572,6 +590,13 @@ static int fetch_with_import(struct transport *transport,
 		}
 	}
 	strbuf_release(&buf);
+	if (auto_gc) {
+		struct child_process cmd = CHILD_PROCESS_INIT;
+
+		cmd.git_cmd = 1;
+		strvec_pushl(&cmd.args, "gc", "--auto", "--quiet", NULL);
+		run_command(&cmd);
+	}
 	return 0;
 }
 
@@ -1158,6 +1183,7 @@ 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;