pulse: fix drain

The drain operation does not complete with a sync from the server but
with an event from the stream. Set a flag in the operation that it
completes with a sync. Keep all operations without a sync around in
the list.

pipewire-pulseaudio/src/context.c

@@ -1473,13 +1473,20 @@ static void core_done(void *data, uint32_t id, int seq)
 		}
 	}
 	spa_list_for_each_safe(o, t, &ops, link) {
+		if (!o->sync)
+			continue;
 		pa_operation_ref(o);
-		pw_log_debug("operation %p complete", o);
+		pw_log_debug("sync operation %p complete", o);
 		if (o->callback)
 			o->callback(o, o->userdata);
 		pa_operation_unref(o);
 	}
 	spa_list_consume(o, &ops, link) {
+		if (!o->sync) {
+			spa_list_remove(&o->link);
+			spa_list_append(&c->operations, &o->link);
+			continue;
+		}
 		pw_log_warn("operation %p canceled", o);
 		pa_operation_cancel(o);
 	}

pipewire-pulseaudio/src/internal.h

@@ -491,6 +491,7 @@ struct pa_operation
 	int refcount;
 	pa_context *context;
 	pa_stream *stream;
+	unsigned int sync:1;
 
 	pa_operation_state_t state;
 

pipewire-pulseaudio/src/operation.c

@@ -52,6 +52,7 @@ int pa_operation_sync(pa_operation *o)
 {
 	pa_context *c = o->context;
 	c->pending_seq = pw_core_sync(c->core, PW_ID_CORE, 0);
+	o->sync = true;
 	pw_log_debug("operation %p: sync seq:%d", o, c->pending_seq);
 	return 0;
 }

pipewire-pulseaudio/src/stream.c

@@ -461,6 +461,8 @@ static void stream_drained(void *data)
 {
 	pa_stream *s = data;
 
+	pw_log_debug("drained");
+
 	if (s->drain) {
 		pa_operation *o = s->drain;
 		pa_operation_ref(o);