Fix double construct leak

Author: iluuu1994

ext/reflection/php_reflection.c

@@ -7242,7 +7242,9 @@ ZEND_METHOD(ReflectionConstant, __construct)
 	intern->ptr = const_;
 	intern->ref_type = REF_TYPE_OTHER;
 
-	ZVAL_STR_COPY(reflection_prop_name(object), name);
+	zval *name_zv = reflection_prop_name(object);
+	zval_ptr_dtor(name_zv);
+	ZVAL_STR_COPY(name_zv, name);
 }
 
 ZEND_METHOD(ReflectionConstant, getName)

ext/reflection/tests/ReflectionConstant_double_construct.phpt

@@ -0,0 +1,24 @@
+--TEST--
+ReflectionConstant double construct call
+--FILE--
+<?php
+
+const C1 = 42;
+const C2 = 43;
+
+$r = new ReflectionConstant('C' . mt_rand(1, 1));
+var_dump($r);
+
+$r->__construct('C' . mt_rand(2, 2));
+var_dump($r);
+
+?>
+--EXPECT--
+object(ReflectionConstant)#1 (1) {
+  ["name"]=>
+  string(2) "C1"
+}
+object(ReflectionConstant)#1 (1) {
+  ["name"]=>
+  string(2) "C2"
+}