Fixed bug #72581 (previous property undefined in Exception after deserialization)

NEWS

@@ -3,6 +3,8 @@ PHP                                                                        NEWS
 ?? ??? 2016 PHP 7.0.10
 
 - Core:
+  . Fixed bug #72581 (previous property undefined in Exception after
+    deserialization). (Laruence)
   . Fixed bug #72496 (Cannot declare public method with signature incompatible
     with parent private method). (Pedro Magalhães)
   . Fixed bug #72024 (microtime() leaks memory). (maroszek at gmx dot net)

Zend/tests/bug72581.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Bug #72581 (previous property undefined in Exception after deserialization)
+--FILE--
+<?php
+
+$e = new Exception('aaa', 200);
+
+$a = serialize($e);
+
+$b = unserialize($a);
+
+var_dump($b->__toString());
+?>
+--EXPECTF--
+string(%s) "Exception: aaa in %sbug72581.php:%d
+Stack trace:
+#0 {main}"

Zend/zend_exceptions.c

@@ -291,9 +291,8 @@ ZEND_METHOD(exception, __construct)
 /* {{{ proto Exception::__wakeup()
    Exception unserialize checks */
 #define CHECK_EXC_TYPE(name, type) \
-	ZVAL_UNDEF(&value); \
 	pvalue = zend_read_property(i_get_exception_base(object), (object), name, sizeof(name) - 1, 1, &value); \
-	if(Z_TYPE_P(pvalue) != IS_UNDEF && Z_TYPE_P(pvalue) != type) { \
+	if (Z_TYPE_P(pvalue) != IS_NULL && Z_TYPE_P(pvalue) != type) { \
 		zval tmp; \
 		ZVAL_STRINGL(&tmp, name, sizeof(name) - 1); \
 		Z_OBJ_HANDLER_P(object, unset_property)(object, &tmp, NULL); \