Check for object_init_ex() failure in user filter factory

ext/standard/tests/filters/object_init_failure.phpt

@@ -0,0 +1,19 @@
+--TEST--
+Creating the stream filter object may fail
+--FILE--
+<?php
+class SampleFilter extends php_user_filter {
+    private $data = \FOO;
+}
+stream_filter_register('sample.filter', SampleFilter::class);
+try {
+    var_dump(file_get_contents('php://filter/read=sample.filter/resource='. __FILE__));
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+?>
+--EXPECTF--
+Warning: file_get_contents(): unable to create or locate filter "sample.filter" in %s on line %d
+
+Warning: file_get_contents(): Unable to create filter (sample.filter) in %s on line %d
+Undefined constant 'FOO'

ext/standard/user_filters.c

@@ -323,14 +323,17 @@ static php_stream_filter *user_filter_factory_create(const char *filtername,
 		}
 	}
 
+	/* create the object */
+	if (object_init_ex(&obj, fdat->ce) == FAILURE) {
+		return NULL;
+	}
+
 	filter = php_stream_filter_alloc(&userfilter_ops, NULL, 0);
 	if (filter == NULL) {
+		zval_ptr_dtor(&obj);
 		return NULL;
 	}
 
-	/* create the object */
-	object_init_ex(&obj, fdat->ce);
-
 	/* filtername */
 	add_property_string(&obj, "filtername", (char*)filtername);