Fix coroutine scope tracking race condition

  Move scope reference assignment from async_new_coroutine() to scope_before_coroutine_enqueue()
  to ensure coroutines are added to scope->coroutines array before scope is set. This prevents
  crashes when coroutines finish between creation and enqueue.

  Fixes assertion failures: "Scope should be empty before disposal"

Author: EdmondDantes

coroutine.c

@@ -338,15 +338,17 @@ zend_coroutine_t *async_new_coroutine(zend_async_scope_t *scope)
 
 	async_coroutine_t *coroutine = (async_coroutine_t *) ZEND_ASYNC_OBJECT_TO_EVENT(object);
 
-	// Add the coroutine to the scope before calling the enqueue hook
-	zval options;
-	ZVAL_UNDEF(&options);
-	if (!scope->before_coroutine_enqueue(&coroutine->coroutine, scope, &options)) {
+	if (scope != NULL) {
+		// Add the coroutine to the scope before calling the enqueue hook
+		zval options;
+		ZVAL_UNDEF(&options);
+		if (!scope->before_coroutine_enqueue(&coroutine->coroutine, scope, &options)) {
+			zval_ptr_dtor(&options);
+			coroutine->coroutine.event.dispose(&coroutine->coroutine.event);
+			return NULL;
+		}
 		zval_ptr_dtor(&options);
-		coroutine->coroutine.event.dispose(&coroutine->coroutine.event);
-		return NULL;
 	}
-	zval_ptr_dtor(&options);
 
 	return &coroutine->coroutine;
 }

scheduler.c

@@ -798,14 +798,6 @@ bool async_scheduler_launch(void)
 		return false;
 	}
 
-	zval options;
-	ZVAL_UNDEF(&options);
-	if (!scope->before_coroutine_enqueue(&main_coroutine->coroutine, scope, &options)) {
-		zval_ptr_dtor(&options);
-		return false;
-	}
-	zval_ptr_dtor(&options);
-
 	scope->after_coroutine_enqueue(&main_coroutine->coroutine, scope);
 	if (UNEXPECTED(EG(exception) != NULL)) {
 		return false;
@@ -876,6 +868,7 @@ bool async_scheduler_launch(void)
 		return false;
 	}
 
+	zval options;
 	ZVAL_UNDEF(&options);
 	if (!scope->before_coroutine_enqueue(scheduler_coroutine, scope, &options)) {
 		zval_ptr_dtor(&options);
@@ -1035,7 +1028,7 @@ bool async_scheduler_coroutine_enqueue(zend_coroutine_t *coroutine)
 				if (UNEXPECTED(zend_hash_index_add_ptr(&ASYNC_G(coroutines), ((async_coroutine_t *)coroutine)->std.handle, coroutine) == NULL)) {
 					coroutine->waker->status = ZEND_ASYNC_WAKER_IGNORED;
 					async_throw_error("Failed to add coroutine to the list");
-					return NULL;
+					return false;
 				}
 
 				ZEND_ASYNC_INCREASE_COROUTINE_COUNT;