Narrow ArrayIterator::key() return type

This can only return string|int|null, not any key type.

Author: nikic

Zend/tests/foreach_004.phpt

@@ -18,7 +18,7 @@ class IT extends ArrayIterator {
 
     function rewind(): void  {$this->trap(__FUNCTION__); parent::rewind();}
     function valid(): bool   {$this->trap(__FUNCTION__); return parent::valid();}
-    function key(): mixed    {$this->trap(__FUNCTION__); return parent::key();}
+    function key(): string|int|null { $this->trap(__FUNCTION__); return parent::key(); }
     function next(): void    {$this->trap(__FUNCTION__); parent::next();}
 }
 

ext/spl/spl_array.stub.php

@@ -204,7 +204,7 @@ public function rewind(): void {}
     public function current(): mixed {}
 
     /** @tentative-return-type */
-    public function key(): mixed {}
+    public function key(): string|int|null {}
 
     /** @tentative-return-type */
     public function next(): void {}

ext/spl/spl_array_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: d58390328052e8db45a6e388ab1b3fdf882be635 */
+ * Stub hash: e8e9909c2548a2259ba58ecf9f2ad6fe5add70f4 */
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_ArrayObject___construct, 0, 0, 0)
 	ZEND_ARG_TYPE_MASK(0, array, MAY_BE_ARRAY|MAY_BE_OBJECT, "[]")
@@ -134,7 +134,8 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_ArrayIterator_current, 0, 0, IS_MIXED, 0)
 ZEND_END_ARG_INFO()
 
-#define arginfo_class_ArrayIterator_key arginfo_class_ArrayIterator_current
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_ArrayIterator_key, 0, 0, MAY_BE_STRING|MAY_BE_LONG|MAY_BE_NULL)
+ZEND_END_ARG_INFO()
 
 #define arginfo_class_ArrayIterator_next arginfo_class_ArrayIterator_rewind
 

ext/spl/tests/arrayObject_getIteratorClass_basic1.phpt

@@ -33,7 +33,7 @@ class MyIterator extends ArrayIterator {
         parent::next();
     }
 
-    function key(): mixed {
+    function key(): string|int|null {
         $args = func_get_args();
         echo "   In " . __METHOD__ . "(" . implode(',', $args) . ")\n";
         return parent::key();

ext/spl/tests/array_020.phpt

@@ -17,7 +17,7 @@ class ArrayIteratorEx extends ArrayIterator
         return ArrayIterator::valid();
     }
 
-    function key(): mixed
+    function key(): string|int|null
     {
         echo __METHOD__ . "\n";
         return ArrayIterator::key();

ext/spl/tests/bug65328.phpt

@@ -226,7 +226,7 @@ class Node extends \RecursiveArrayIterator implements \Countable
     /**
      * @return scalar
      */
-    public function key(): mixed
+    public function key(): string|int|null
     {
         return $this->index;
     }

ext/spl/tests/iterator_007.phpt

@@ -20,7 +20,7 @@ class ArrayIteratorEx extends ArrayIterator
         echo __METHOD__ . "\n";
         return parent::current();
     }
-    function key(): mixed
+    function key(): string|int|null
     {
         echo __METHOD__ . "\n";
         return parent::key();

ext/spl/tests/iterator_008.phpt

@@ -20,7 +20,7 @@ class ArrayIteratorEx extends ArrayIterator
         echo __METHOD__ . "\n";
         return parent::current();
     }
-    function key(): mixed
+    function key(): string|int|null
     {
         echo __METHOD__ . "\n";
         return parent::key();

ext/spl/tests/iterator_041.phpt

@@ -42,7 +42,7 @@ class MyArrayIterator extends ArrayIterator
         return parent::current();
     }
 
-    function key(): mixed
+    function key(): string|int|null
     {
         self::fail(5, __FUNCTION__);
         return parent::key();

ext/spl/tests/iterator_041a.phpt

@@ -42,7 +42,7 @@ class MyArrayIterator extends ArrayIterator
         return parent::current();
     }
 
-    function key(): mixed
+    function key(): string|int|null
     {
         self::fail(5, __FUNCTION__);
         return parent::key();

ext/spl/tests/iterator_041b.phpt

@@ -42,7 +42,7 @@ class MyArrayIterator extends ArrayIterator
         return parent::current();
     }
 
-    function key(): mixed
+    function key(): string|int|null
     {
         self::fail(5, __FUNCTION__);
         return parent::key();