Merge branch 'jk/epipe-in-async'

Handling of errors while writing into our internal asynchronous
process has been made more robust, which reduces flakiness in our
tests.

* jk/epipe-in-async:
  t5504: handle expected output from SIGPIPE death
  test_must_fail: report number of unexpected signal
  fetch-pack: ignore SIGPIPE in sideband demuxer
  write_or_die: handle EPIPE in async threads

run-command.c

@@ -625,6 +625,11 @@ int in_async(void)
 	return !pthread_equal(main_thread, pthread_self());
 }
 
+void NORETURN async_exit(int code)
+{
+	pthread_exit((void *)(intptr_t)code);
+}
+
 #else
 
 static struct {
@@ -670,6 +675,11 @@ int in_async(void)
 	return process_is_async;
 }
 
+void NORETURN async_exit(int code)
+{
+	exit(code);
+}
+
 #endif
 
 int start_async(struct async *async)