[BUGFIX] Fix ForViewHelper iteration total for traversables

Use iterator conversion when calculating the total iteration count so
non-countable traversable values can be used with the iteration argument.

Add functional coverage for an IteratorAggregate that does not implement
Countable.

related: https://forge.typo3.org/issues/110129

Author: Kanti

src/ViewHelpers/ForViewHelper.php

@@ -106,7 +106,7 @@ public function render(): string
             $iterationData = [
                 'index' => 0,
                 'cycle' => 1,
-                'total' => count($this->arguments['each']),
+                'total' => count(is_countable($this->arguments['each']) ? $this->arguments['each'] : iterator_to_array($this->arguments['each'])),
             ];
         }
         $globalVariableProvider = $this->renderingContext->getVariableProvider();

tests/Functional/ViewHelpers/ForViewHelperTest.php

@@ -107,6 +107,19 @@ public static function renderDataProvider(): \Generator
             . '</ul>',
         ];
 
+        $value = new class () implements \IteratorAggregate {
+            public function getIterator(): \Traversable
+            {
+                yield 'first' => 'foo';
+                yield 'second' => 'bar';
+            }
+        };
+        yield 'iterator total works for non countable traversable' => [
+            '<f:for each="{value}" as="item" iteration="iterator">{item}: {iterator.total}, </f:for>',
+            ['value' => $value],
+            'foo: 2, bar: 2, ',
+        ];
+
         $value = ['item'];
         yield 'iterator not available if not requested' => [
             '<f:for each="{value}" as="item">Total: {iterator.total}</f:for>',