MFB: Fixed bug #42177 (Warning "array_merge_recursive(): recursion detected" comes again...)

ext/standard/array.c

@@ -2410,7 +2410,7 @@ ukey:
 				if (recursive && zend_u_hash_find(dest, utype, string_key, string_key_len, (void **)&dest_entry) == SUCCESS) {
 					HashTable *thash = HASH_OF(*dest_entry);
 
-					if ((thash && thash->nApplyCount > 1) || (*src_entry == *dest_entry && (Z_REFCOUNT_PP(dest_entry) % 2))) {
+					if ((thash && thash->nApplyCount > 1) || (*src_entry == *dest_entry && Z_ISREF_PP(dest_entry) && (Z_REFCOUNT_PP(dest_entry) % 2))) {
 						php_error_docref(NULL TSRMLS_CC, E_WARNING, "recursion detected");
 						return 0;
 					}

ext/standard/tests/array/bug42177.phpt

@@ -0,0 +1,34 @@
+--TEST--
+Bug #42177 (Warning "array_merge_recursive(): recursion detected" comes again...)
+--FILE--
+<?php
+
+$a1 = array( 'key1' => 1, 'key3' => 2 );
+$a2 = array();
+$a1 = array_merge_recursive( $a1, $a2 );
+$a1 = array_merge_recursive( $a1, $a2 );
+unset( $a1, $a2 );
+
+$a1 = array();
+$a2 = array( 'key1' => 1, 'key3' => 2 );
+$a1 = array_merge_recursive( $a1, $a2 );
+$a1 = array_merge_recursive( $a1, $a2 );
+unset( $a1, $a2 );
+
+$a1 = array();
+$a2 = array( 'key1' => &$a1 );
+$a1 = array_merge_recursive( $a1, $a2 );
+$a1 = array_merge_recursive( $a1, $a2 );
+unset( $a1, $a2 );
+
+$x = 'foo';
+$y =& $x;
+$a1 = array($x, $y, $x, $y);
+$a2 = array( 'key1' => $a1, $x, $y );
+$a1 = array_merge_recursive( $a1, $a2 );
+$a1 = array_merge_recursive( $a1, $a2 );
+unset( $a1, $a2 );
+
+?>
+--EXPECTF--
+Warning: array_merge_recursive(): recursion detected in %s on line 18