Fix #69202: FILTER_FLAG_STRIP_BACKTICK ignored unless other flags are used.

Author: whatthejeff

ext/filter/sanitizing_filters.c

@@ -115,7 +115,7 @@ static void php_filter_strip(zval *value, zend_long flags)
 	zend_string *buf;
 
 	/* Optimization for if no strip flags are set */
-	if (! ((flags & FILTER_FLAG_STRIP_LOW) || (flags & FILTER_FLAG_STRIP_HIGH)) ) {
+	if (!(flags & (FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH | FILTER_FLAG_STRIP_BACKTICK))) {
 		return;
 	}
 

ext/filter/tests/bug69202.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Bug #69202 (FILTER_FLAG_STRIP_BACKTICK ignored unless other flags are used)
+--SKIPIF--
+<?php if (!extension_loaded("filter")) die("skip"); ?>
+--FILE--
+<?php
+var_dump(filter_var("``a`b`c``", FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_BACKTICK));
+var_dump(filter_var("``a`b`c``", FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_BACKTICK));
+var_dump(filter_var("``a`b`c``", FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH | FILTER_FLAG_STRIP_BACKTICK));
+var_dump(filter_var("``a`b`c``", FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH));
+?>
+--EXPECT--
+string(3) "abc"
+string(3) "abc"
+string(3) "abc"
+string(9) "``a`b`c``"