Fix memory leak when user filter onCreate returns false

Author: nikic

ext/standard/tests/filters/php_user_filter_onCreate_failure.phpt

@@ -0,0 +1,24 @@
+--TEST--
+php_user_filter onCreate() returns false
+--FILE--
+<?php
+
+class my_filter extends php_user_filter {
+    function onCreate() {
+        return false;
+    }
+}
+
+stream_filter_register("my_filter", "my_filter");
+$fp = fopen('php://memory', 'rw');
+var_dump(stream_filter_append($fp, "my_filter"));
+fwrite($fp, "Test");
+fseek($fp, 0);
+var_dump(fgets($fp));
+fclose($fp);
+
+?>
+--EXPECTF--
+Warning: stream_filter_append(): Unable to create or locate filter "my_filter" in %s on line %d
+bool(false)
+string(4) "Test"

ext/standard/user_filters.c

@@ -342,6 +342,8 @@ static php_stream_filter *user_filter_factory_create(const char *filtername,
 			&retval,
 			0, NULL);
 
+	zval_ptr_dtor(&func_name);
+
 	if (Z_TYPE(retval) != IS_UNDEF) {
 		if (Z_TYPE(retval) == IS_FALSE) {
 			/* User reported filter creation error "return false;" */
@@ -359,7 +361,6 @@ static php_stream_filter *user_filter_factory_create(const char *filtername,
 		}
 		zval_ptr_dtor(&retval);
 	}
-	zval_ptr_dtor(&func_name);
 
 	/* set the filter property, this will be used during cleanup */
 	ZVAL_RES(&zfilter, zend_register_resource(filter, le_userfilters));