[BUGFIX] Handle array access in LocalImageProcessor

Handle missing image dimensions (width, height)
without throwing an exception.

In same cases, image dimension may not be able to be
set properly.

Resolves: #99406
Releases: main, 11.5
Change-Id: I81124dcaf29932448a87b69ab5bf6445eeb7469c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77844
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/core/Classes/Resource/Processing/LocalImageProcessor.php

@@ -114,8 +114,8 @@ protected function checkForExistingTargetFile(TaskInterface $task)
             $task->setExecuted(true);
             $imageDimensions = $this->getGraphicalFunctionsObject()->getImageDimensions($localProcessedFile);
             $properties = [
-                'width' => $imageDimensions[0],
-                'height' => $imageDimensions[1],
+                'width' => $imageDimensions[0] ?? 0,
+                'height' => $imageDimensions[1] ?? 0,
                 'size' => filesize($localProcessedFile),
                 'checksum' => $task->getConfigurationChecksum(),
             ];