Fixed bug #70240 (Segfault when doing unset($var());)

NEWS

@@ -3,6 +3,7 @@ PHP                                                                        NEWS
 20 Aug 2015, PHP 7.0.0 RC 1
 
 - Core:
+  . Fixed bug #70240 (Segfault when doing unset($var());). (Laruence)
   . Fixed bug #70223 (Incrementing value returned by magic getter). (Laruence)
   . Fixed bug #70215 (Segfault when __invoke is static). (Bob)
   . Fixed bug #70207 (Finally is broken with opcache). (Laruence, Dmitry)

Zend/tests/bug70240.phpt

@@ -0,0 +1,8 @@
+--TEST--
+Bug #70240 (Segfault when doing unset($var()))
+--FILE--
+<?php
+unset($var());
+?>
+--EXPECTF--
+Fatal error: Can't use function return value in write context in %sbug70240.php on line %d

Zend/zend_compile.c

@@ -3428,9 +3428,11 @@ void zend_compile_static_var(zend_ast *ast) /* {{{ */
 void zend_compile_unset(zend_ast *ast) /* {{{ */
 {
 	zend_ast *var_ast = ast->child[0];
-
 	znode var_node;
 	zend_op *opline;
+
+	zend_ensure_writable_variable(var_ast);
+
 	switch (var_ast->kind) {
 		case ZEND_AST_VAR:
 			if (zend_try_compile_cv(&var_node, var_ast) == SUCCESS) {