Fix leak in isDefaultValueAvailable()

Exposed in Symfony due to exit changes.

Author: nikic

ext/reflection/php_reflection.c

@@ -2813,10 +2813,11 @@ ZEND_METHOD(ReflectionParameter, isDefaultValueConstant)
 	if (Z_TYPE(default_value) == IS_CONSTANT_AST) {
 		zend_ast *ast = Z_ASTVAL(default_value);
 		RETVAL_BOOL(ast->kind == ZEND_AST_CONSTANT || ast->kind == ZEND_AST_CONSTANT_CLASS);
-		zval_ptr_dtor_nogc(&default_value);
 	} else {
-		RETURN_FALSE;
+		RETVAL_FALSE;
 	}
+
+	zval_ptr_dtor_nogc(&default_value);
 }
 /* }}} */
 

ext/reflection/tests/default_value_leak.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Check that isDefaultValueConstant() does not leak
+--FILE--
+<?php
+
+class Test {
+    public function method($param = [123]) {}
+}
+
+$rp = new ReflectionParameter(['Test', 'method'], 'param');
+var_dump($rp->isDefaultValueAvailable());
+var_dump($rp->isDefaultValueConstant());
+var_dump($rp->getDefaultValue());
+
+?>
+--EXPECT--
+bool(true)
+bool(false)
+array(1) {
+  [0]=>
+  int(123)
+}