- Nuke empty_string. It is a reminanent from the time where RETURN_FALSE()

  used to return "" and not bool(false). It's not worth keeping it because
  STR_FREE() and zval_dtor() always have to check for it and it slows down
  the general case. In addition, it seems that empty_string has been abused
  quite a lot, and was used not only for setting zval's but generally in
  PHP code instead of "", which wasn't the intention. Last but not least,
  nuking empty_string should improve stability as I doubt every place
  correctly checked if they are not mistakenly erealloc()'ing it or
  calling efree() on it.
  NOTE: Some code is probably broken. Each extension maintainer should
  check and see that my changes are OK. Also, I haven't had time to touch
  PECL yet. Will try and do it tomorrow.

1 files changed, 6 insertions, 3 deletions

diff --git a/ext/session/session.c b/ext/session/session.c
index 135a732253..f5efc8ba9d 100644
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -1060,7 +1060,7 @@ static void php_session_reset_id(TSRMLS_D)
 		smart_str_0(&var);
 		REGISTER_STRINGL_CONSTANT("SID", var.c, var.len, 0);
 	} else {
-		REGISTER_STRINGL_CONSTANT("SID", empty_string, 0, 0);
+		REGISTER_STRINGL_CONSTANT("SID", "", 0, 1);
 	}
 
 	if (PS(apply_trans_sid)) {
@@ -1370,13 +1370,16 @@ PHP_FUNCTION(session_id)
 {
 	zval **p_name;
 	int ac = ZEND_NUM_ARGS();
-	char *old = empty_string;
+	char *old;
 
 	if (ac < 0 || ac > 1 || zend_get_parameters_ex(ac, &p_name) == FAILURE)
 		WRONG_PARAM_COUNT;
 
-	if (PS(id))
+	if (PS(id)) {
 		old = estrdup(PS(id));
+	} else {
+		old = STR_EMPTY_ALLOC();
+	}
 
 	if (ac == 1) {
 		convert_to_string_ex(p_name);