1 files changed, 58 insertions, 18 deletions

diff --git a/transport-helper.c b/transport-helper.c
index 6f227e253b..4713b69302 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -9,6 +9,8 @@
 #include "remote.h"
 #include "string-list.h"
 #include "thread-utils.h"
+#include "sigchain.h"
+#include "argv-array.h"
 
 static int debug;
 
@@ -18,6 +20,7 @@ struct helper_data {
 	FILE *out;
 	unsigned fetch : 1,
 		import : 1,
+		bidi_import : 1,
 		export : 1,
 		option : 1,
 		push : 1,
@@ -100,6 +103,7 @@ static void do_take_over(struct transport *transport)
 static struct child_process *get_helper(struct transport *transport)
 {
 	struct helper_data *data = transport->data;
+	struct argv_array argv = ARGV_ARRAY_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process *helper;
 	const char **refspecs = NULL;
@@ -121,11 +125,10 @@ static struct child_process *get_helper(struct transport *transport)
 	helper->in = -1;
 	helper->out = -1;
 	helper->err = 0;
-	helper->argv = xcalloc(4, sizeof(*helper->argv));
-	strbuf_addf(&buf, "git-remote-%s", data->name);
-	helper->argv[0] = strbuf_detach(&buf, NULL);
-	helper->argv[1] = transport->remote->name;
-	helper->argv[2] = remove_ext_force(transport->url);
+	argv_array_pushf(&argv, "git-remote-%s", data->name);
+	argv_array_push(&argv, transport->remote->name);
+	argv_array_push(&argv, remove_ext_force(transport->url));
+	helper->argv = argv_array_detach(&argv, NULL);
 	helper->git_cmd = 0;
 	helper->silent_exec_failure = 1;
 
@@ -177,6 +180,8 @@ static struct child_process *get_helper(struct transport *transport)
 			data->push = 1;
 		else if (!strcmp(capname, "import"))
 			data->import = 1;
+		else if (!strcmp(capname, "bidi-import"))
+			data->bidi_import = 1;
 		else if (!strcmp(capname, "export"))
 			data->export = 1;
 		else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
@@ -198,7 +203,7 @@ static struct child_process *get_helper(struct transport *transport)
 			data->import_marks = strbuf_detach(&arg, NULL);
 		} else if (mandatory) {
 			die("Unknown mandatory capability %s. This remote "
-			    "helper probably needs newer version of Git.\n",
+			    "helper probably needs newer version of Git.",
 			    capname);
 		}
 	}
@@ -220,22 +225,27 @@ static struct child_process *get_helper(struct transport *transport)
 static int disconnect_helper(struct transport *transport)
 {
 	struct helper_data *data = transport->data;
-	struct strbuf buf = STRBUF_INIT;
 	int res = 0;
 
 	if (data->helper) {
 		if (debug)
 			fprintf(stderr, "Debug: Disconnecting.\n");
 		if (!data->no_disconnect_req) {
-			strbuf_addf(&buf, "\n");
-			sendline(data, &buf);
+			/*
+			 * Ignore write errors; there's nothing we can do,
+			 * since we're about to close the pipe anyway. And the
+			 * most likely error is EPIPE due to the helper dying
+			 * to report an error itself.
+			 */
+			sigchain_push(SIGPIPE, SIG_IGN);
+			xwrite(data->helper->in, "\n", 1);
+			sigchain_pop(SIGPIPE);
 		}
 		close(data->helper->in);
 		close(data->helper->out);
 		fclose(data->out);
 		res = finish_command(data->helper);
-		free((char *)data->helper->argv[0]);
-		free(data->helper->argv);
+		argv_array_free_detached(data->helper->argv);
 		free(data->helper);
 		data->helper = NULL;
 	}
@@ -369,14 +379,23 @@ static int fetch_with_fetch(struct transport *transport,
 static int get_importer(struct transport *transport, struct child_process *fastimport)
 {
 	struct child_process *helper = get_helper(transport);
+	struct helper_data *data = transport->data;
+	struct argv_array argv = ARGV_ARRAY_INIT;
+	int cat_blob_fd, code;
 	memset(fastimport, 0, sizeof(*fastimport));
 	fastimport->in = helper->out;
-	fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
-	fastimport->argv[0] = "fast-import";
-	fastimport->argv[1] = "--quiet";
+	argv_array_push(&argv, "fast-import");
+	argv_array_push(&argv, debug ? "--stats" : "--quiet");
 
+	if (data->bidi_import) {
+		cat_blob_fd = xdup(helper->in);
+		argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
+	}
+	fastimport->argv = argv.argv;
 	fastimport->git_cmd = 1;
-	return start_command(fastimport);
+
+	code = start_command(fastimport);
+	return code;
 }
 
 static int get_exporter(struct transport *transport,
@@ -431,12 +450,33 @@ static int fetch_with_import(struct transport *transport,
 	}
 
 	write_constant(data->helper->in, "\n");
+	/*
+	 * remote-helpers that advertise the bidi-import capability are required to
+	 * buffer the complete batch of import commands until this newline before
+	 * sending data to fast-import.
+	 * These helpers read back data from fast-import on their stdin, which could
+	 * be mixed with import commands, otherwise.
+	 */
 
 	if (finish_command(&fastimport))
 		die("Error while running fast-import");
-	free(fastimport.argv);
-	fastimport.argv = NULL;
+	argv_array_free_detached(fastimport.argv);
 
+	/*
+	 * The fast-import stream of a remote helper that advertises
+	 * the "refspec" capability writes to the refs named after the
+	 * right hand side of the first refspec matching each ref we
+	 * were fetching.
+	 *
+	 * (If no "refspec" capability was specified, for historical
+	 * reasons we default to *:*.)
+	 *
+	 * Store the result in to_fetch[i].old_sha1.  Callers such
+	 * as "git fetch" can use the value to write feedback to the
+	 * terminal, populate FETCH_HEAD, and determine what new value
+	 * should be written to peer_ref if the update is a
+	 * fast-forward or this is a forced update.
+	 */
 	for (i = 0; i < nr_heads; i++) {
 		char *private;
 		posn = to_fetch[i];
@@ -592,7 +632,7 @@ static void push_update_ref_status(struct strbuf *buf,
 		status = REF_STATUS_REMOTE_REJECT;
 		refname = buf->buf + 6;
 	} else
-		die("expected ok/error, helper said '%s'\n", buf->buf);
+		die("expected ok/error, helper said '%s'", buf->buf);
 
 	msg = strchr(refname, ' ');
 	if (msg) {