[VarDumper] fix mutating $GLOBALS while cloning it

Author: nicolas-grekas

Cloner/Data.php

@@ -335,7 +335,7 @@ private function dumpItem(DumperInterface $dumper, Cursor $cursor, array &$refs,
                 }
                 $cursor->hardRefTo = $refs[$r];
                 $cursor->hardRefHandle = $this->useRefHandles & $item->handle;
-                $cursor->hardRefCount = $item->refCount;
+                $cursor->hardRefCount = 0 < $item->handle ? $item->refCount : 0;
             }
             $cursor->attr = $item->attr;
             $type = $item->class ?: \gettype($item->value);

Cloner/VarCloner.php

@@ -159,13 +159,19 @@ protected function doClone($var)
                         if (Stub::ARRAY_ASSOC === $stub->class) {
                             // Copies of $GLOBALS have very strange behavior,
                             // let's detect them with some black magic
-                            $a[$gid] = true;
-
-                            // Happens with copies of $GLOBALS
-                            if (isset($v[$gid])) {
+                            if (\PHP_VERSION_ID < 80100 && ($a[$gid] = true) && isset($v[$gid])) {
                                 unset($v[$gid]);
                                 $a = [];
                                 foreach ($v as $gk => &$gv) {
+                                    if ($v === $gv) {
+                                        unset($v);
+                                        $v = new Stub();
+                                        $v->value = [$v->cut = \count($gv), Stub::TYPE_ARRAY => 0];
+                                        $v->handle = -1;
+                                        $gv = &$hardRefs[spl_object_id($v)];
+                                        $gv = $v;
+                                    }
+
                                     $a[$gk] = &$gv;
                                 }
                                 unset($gv);

Tests/Dumper/CliDumperTest.php

@@ -439,6 +439,7 @@ public function testRefsInProperties()
     /**
      * @runInSeparateProcess
      * @preserveGlobalState disabled
+     * @requires PHP < 8.1
      */
     public function testSpecialVars56()
     {
@@ -453,11 +454,11 @@ public function testSpecialVars56()
     ]
   ]
   1 => array:1 [
-    "GLOBALS" => &2 array:1 [
-      "GLOBALS" => &2 array:1 [&2]
-    ]
+    "GLOBALS" => & array:1 [ …1]
+  ]
+  2 => &3 array:1 [
+    "GLOBALS" => &3 array:1 [&3]
   ]
-  2 => &2 array:1 [&2]
 ]
 EOTXT
             ,
@@ -468,6 +469,7 @@ public function testSpecialVars56()
     /**
      * @runInSeparateProcess
      * @preserveGlobalState disabled
+     * @requires PHP < 8.1
      */
     public function testGlobals()
     {
@@ -490,11 +492,11 @@ public function testGlobals()
             <<<'EOTXT'
 array:2 [
   1 => array:1 [
-    "GLOBALS" => &1 array:1 [
-      "GLOBALS" => &1 array:1 [&1]
-    ]
+    "GLOBALS" => & array:1 [ …1]
+  ]
+  2 => &2 array:1 [
+    "GLOBALS" => &2 array:1 [&2]
   ]
-  2 => &1 array:1 [&1]
 ]
 
 EOTXT
@@ -584,6 +586,6 @@ private function getSpecialVars()
             return $var;
         };
 
-        return [$var(), $GLOBALS, &$GLOBALS];
+        return eval('return [$var(), $GLOBALS, &$GLOBALS];');
     }
 }