remote-ext: simplify git pkt-line generation

We format a pkt-line into a heap buffer, which requires
manual computation of the required size, and uses some bare
sprintf calls. We could use a strbuf instead, which would
take care of the computation for us. But it's even easier
still to use packet_write(). Besides handling the formatting
and writing for us, it fixes two things:

  1. Our manual max-size check used 0xFFFF, while technically
     LARGE_PACKET_MAX is slightly smaller than this.

  2. Our packet will now be output as part of
     GIT_TRACE_PACKET debugging.

Unfortunately packet_write() does not let us build up the
buffer progressively, so we do have to repeat ourselves a
little depending on the "vhost" setting, but the end result
is still far more readable than the original.

Since there were no tests covering this feature at all,
we'll add a few into t5802.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 29 deletions

diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c
index 3b8c22cc75e..e3cd25d580b 100644
--- a/builtin/remote-ext.c
+++ b/builtin/remote-ext.c
@@ -1,6 +1,7 @@
 #include "builtin.h"
 #include "transport.h"
 #include "run-command.h"
+#include "pkt-line.h"
 
 /*
  * URL syntax:
@@ -142,36 +143,11 @@ static const char **parse_argv(const char *arg, const char *service)
 static void send_git_request(int stdin_fd, const char *serv, const char *repo,
 	const char *vhost)
 {
-	size_t bufferspace;
-	size_t wpos = 0;
-	char *buffer;
-
-	/*
-	 * Request needs 12 bytes extra if there is vhost (xxxx \0host=\0) and
-	 * 6 bytes extra (xxxx \0) if there is no vhost.
-	 */
-	if (vhost)
-		bufferspace = strlen(serv) + strlen(repo) + strlen(vhost) + 12;
+	if (!vhost)
+		packet_write(stdin_fd, "%s %s%c", serv, repo, 0);
 	else
-		bufferspace = strlen(serv) + strlen(repo) + 6;
-
-	if (bufferspace > 0xFFFF)
-		die("Request too large to send");
-	buffer = xmalloc(bufferspace);
-
-	/* Make the packet. */
-	wpos = sprintf(buffer, "%04x%s %s%c", (unsigned)bufferspace,
-		serv, repo, 0);
-
-	/* Add vhost if any. */
-	if (vhost)
-		sprintf(buffer + wpos, "host=%s%c", vhost, 0);
-
-	/* Send the request */
-	if (write_in_full(stdin_fd, buffer, bufferspace) < 0)
-		die_errno("Failed to send request");
-
-	free(buffer);
+		packet_write(stdin_fd, "%s %s%chost=%s%c", serv, repo, 0,
+			     vhost, 0);
 }
 
 static int run_child(const char *arg, const char *service)