Merge branch 'PHP-7.1' into PHP-7.2

* PHP-7.1:
  Fixed #74977 - Appending AppendIterator leads to segfault

NEWS

@@ -37,6 +37,8 @@ PHP                                                                        NEWS
 
 - SPL:
   . Fixed bug #74669 (Unserialize ArrayIterator broken). (Andrew Nester)
+  . Fixed bug #74977 (Appending AppendIterator leads to segfault). 
+    (Andrew Nester)
 
 - Standard:
   . Fixed bug #74851 (uniqid() without more_entropy performs badly).

ext/spl/spl_iterators.c

@@ -3365,7 +3365,7 @@ SPL_METHOD(AppendIterator, __construct)
    Append an iterator */
 SPL_METHOD(AppendIterator, append)
 {
-	spl_dual_it_object   *intern;
+	spl_dual_it_object   *intern, *appender;
 	zval *it;
 
 	SPL_FETCH_AND_CHECK_DUAL_IT(intern, getThis());
@@ -3377,6 +3377,11 @@ SPL_METHOD(AppendIterator, append)
 		spl_array_iterator_append(&intern->u.append.zarrayit, it);
 		intern->u.append.iterator->funcs->move_forward(intern->u.append.iterator);
 	}else{
+		appender = Z_SPLDUAL_IT_P(it);
+		if (appender->dit_type == DIT_AppendIterator) {
+			spl_array_iterator_append(&intern->u.append.zarrayit, &appender->u.append.zarrayit);
+			return;
+		}
 		spl_array_iterator_append(&intern->u.append.zarrayit, it);
 	}
 

ext/spl/tests/bug74977.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Bug #74977:	Recursion leads to crash
+--FILE--
+<?php
+
+$iterator = new AppendIterator(array("A","A","A"));
+$iterator->append($iterator);
+var_dump($iterator);
+?>
+--EXPECTF--
+object(AppendIterator)#1 (0) {
+}
+