Fix crash when first argument to strtr is empty

diff --git a/ext/standard/string.c b/ext/standard/string.c
index 77addf6911c149211c991278c87a08b11b944952..4bdc04ac51d6bad97c6911edc8049de37123fb25 100644 (file)
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -1573,6 +1573,11 @@ PHP_FUNCTION(strtr)
 
        convert_to_string_ex(str);
 
+       /* shortcut for empty string */
+       if(Z_STRLEN_PP(str) == 0) {
+               RETURN_EMPTY_STRING();
+       }
+
        if (ac == 2) {
                php_strtr_array(return_value,(*str)->value.str.val,(*str)->value.str.len,HASH_OF(*from));
        } else {