prefork-interp: New protocol: C: Do exchange even for setup run

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/cprogs/prefork-interp.c b/cprogs/prefork-interp.c
index 91ab3cb9efbc9cbc27e9543ce597cbc418ffab17..b15d61ae328e247ece3a93047aef7ac377786790 100644 (file)
--- a/cprogs/prefork-interp.c
+++ b/cprogs/prefork-interp.c
@@ -387,6 +387,8 @@ static FILE *connect_or_spawn(void) {
   close(sfd);
 
   call_sock = call_sock_from_fd(fake_pair[0]);
+  const char *emsg = protocol_exchange(call_sock);
+  if (emsg) die("setup failed: %s", emsg);
 
   int status;
   pid_t got = waitpid(setup_pid, &status, 0);