Add Tim's suggestion

Author: kamil-tekiela

ext/mysqli/mysqli_api.c

@@ -1198,7 +1198,7 @@ PHP_FUNCTION(mysqli_options)
 		zend_argument_value_error(ERROR_ARG_POS(2), "must be MYSQLI_INIT_COMMAND, MYSQLI_SET_CHARSET_NAME, MYSQLI_SERVER_PUBLIC_KEY, or one of the MYSQLI_OPT_* constants");
 		RETURN_THROWS();
 	}
-	
+
 	if (expected_type != Z_TYPE_P(mysql_value)) {
 		switch (expected_type) {
 			case IS_STRING:
@@ -1375,13 +1375,13 @@ PHP_FUNCTION(mysqli_quote_string) {
 	}
 	MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
 
-	newstr = zend_string_safe_alloc(2, escapestr_len+1, 0, 0);
-	ZSTR_VAL(newstr)[0] = '\'';
-	ZSTR_LEN(newstr) = 1 +  mysql_real_escape_string(mysql->mysql, ZSTR_VAL(newstr) + 1, escapestr, escapestr_len);
-	ZSTR_VAL(newstr)[ZSTR_LEN(newstr)] = '\'';
-	ZSTR_LEN(newstr) += 1;
-	ZSTR_VAL(newstr)[ZSTR_LEN(newstr)] = '\0';
-	newstr = zend_string_truncate(newstr, ZSTR_LEN(newstr), 0);
+	newstr = zend_string_safe_alloc(2, escapestr_len, 2, 0);
+	char *out = ZSTR_VAL(newstr);
+	*out++ = '\'';
+	out += mysql_real_escape_string(mysql->mysql, out, escapestr, escapestr_len);
+	*out++ = '\'';
+	*out = '\0';
+	newstr = zend_string_truncate(newstr, out - ZSTR_VAL(newstr), 0);
 
 	RETURN_NEW_STR(newstr);
 }