+static pid_t setup_sideband(int sideband, const char *me, int fd[2], int xd[2])
+{
+ pid_t side_pid;
+
+ if (!sideband) {
+ fd[0] = xd[0];
+ fd[1] = xd[1];
+ return 0;
+ }
+ /* xd[] is talking with upload-pack; subprocess reads from
+ * xd[0], spits out band#2 to stderr, and feeds us band#1
+ * through our fd[0].
+ */
+ if (pipe(fd) < 0)
+ die("%s: unable to set up pipe", me);
+ side_pid = fork();
+ if (side_pid < 0)
+ die("%s: unable to fork off sideband demultiplexer", me);
+ if (!side_pid) {
+ /* subprocess */
+ close(fd[0]);
+ if (xd[0] != xd[1])
+ close(xd[1]);
+ while (1) {
+ char buf[1024];
+ int len = packet_read_line(xd[0], buf, sizeof(buf));
+ if (len == 0)
+ break;
+ if (len < 1)
+ die("%s: protocol error: no band designator",
+ me);
+ len--;
+ switch (buf[0] & 0xFF) {
+ case 3:
+ safe_write(2, buf+1, len);
+ fprintf(stderr, "\n");
+ exit(1);
+ case 2:
+ safe_write(2, buf+1, len);
+ continue;
+ case 1:
+ safe_write(fd[1], buf+1, len);
+ continue;
+ default:
+ die("%s: protocol error: bad band #%d",
+ me, (buf[0] & 0xFF));
+ }
+ }
+ exit(0);
+ }
+ close(xd[0]);
+ close(fd[1]);
+ fd[1] = xd[1];
+ return side_pid;
+}
+
+int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)