Merge branch 'PHP-7.4'

* PHP-7.4:
  Fixed bug #79778

Author: nikic

Zend/tests/bug79778.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Bug #79778: Assertion failure if dumping closure with unresolved static variable
+--FILE--
+<?php
+$closure1 = function() {
+    static $var = CONST_REF;
+};
+var_dump($closure1);
+print_r($closure1);
+?>
+--EXPECT--
+object(Closure)#1 (1) {
+  ["static"]=>
+  array(1) {
+    ["var"]=>
+    string(14) "<constant ast>"
+  }
+}
+Closure Object
+(
+    [static] => Array
+        (
+            [var] => <constant ast>
+        )
+
+)

Zend/zend_closures.c

@@ -524,10 +524,17 @@ static HashTable *zend_closure_get_debug_info(zend_object *object, int *is_temp)
 	debug_info = zend_new_array(8);
 
 	if (closure->func.type == ZEND_USER_FUNCTION && closure->func.op_array.static_variables) {
+		zval *var;
 		HashTable *static_variables =
 			ZEND_MAP_PTR_GET(closure->func.op_array.static_variables_ptr);
 		ZVAL_ARR(&val, zend_array_dup(static_variables));
 		zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_STATIC), &val);
+		ZEND_HASH_FOREACH_VAL(Z_ARRVAL(val), var) {
+			if (Z_TYPE_P(var) == IS_CONSTANT_AST) {
+				zval_ptr_dtor(var);
+				ZVAL_STRING(var, "<constant ast>");
+			}
+		} ZEND_HASH_FOREACH_END();
 	}
 
 	if (Z_TYPE(closure->this_ptr) != IS_UNDEF) {