Add test instantiating all objects

Intended to find issues in opaque object destructors.

Closes GH-6251.

Author: nikic

Zend/tests/instantiate_all_classes.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Try to instantiate all classes without arguments
+--FILE--
+<?php
+
+foreach (get_declared_classes() as $class) {
+    try {
+        new $class;
+    } catch (Throwable) {}
+}
+
+?>
+===DONE===
+--EXPECT--
+===DONE===

ext/gd/gd.c

@@ -199,9 +199,9 @@ zend_object *php_gd_image_object_create(zend_class_entry *class_type)
 static void php_gd_image_object_free(zend_object *intern)
 {
 	php_gd_image_object *img_obj_ptr = php_gd_exgdimage_from_zobj_p(intern);
-	gdImageDestroy(img_obj_ptr->image);
-	img_obj_ptr->image = NULL;
-
+	if (img_obj_ptr->image) {
+		gdImageDestroy(img_obj_ptr->image);
+	}
 	zend_object_std_dtor(intern);
 }
 

ext/openssl/openssl.c

@@ -233,10 +233,7 @@ static void php_openssl_pkey_free_obj(zend_object *object)
 {
 	php_openssl_pkey_object *key_object = php_openssl_pkey_from_obj(object);
 
-	EVP_PKEY *pkey = key_object->pkey;
-	assert(pkey != NULL);
-	EVP_PKEY_free(pkey);
-
+	EVP_PKEY_free(key_object->pkey);
 	zend_object_std_dtor(&key_object->std);
 }