TYPO3.Flow

When importing a non existing file via ResourceManager::importResource() the ResourceManager kills the PHP process by allocating memory throws an exception
We should check the existence of the specified $uri.
My first draft looks like this:

 1    public function importResource($uri) {
 2        $pathInfo = pathinfo($uri);
 3        if (isset($pathInfo['extension']) && substr(strtolower($pathInfo['extension']), -3, 3) === 'php') {
 4            $this->systemLogger->log('Import of resources with a "php" extension is not allowed.', LOG_WARNING);
 5            return FALSE;
 6        }
 7
 8        // NEW CODE:
 9
10        $responseHeaders = get_headers($uri);
11        $responseCode = (integer)substr($responseHeaders[0], 9, 3);
12        if ($responseCode === 404) {
13            $this->systemLogger->log(sprintf('Could not copy resource from "%s", the file does not exist.', $uri), LOG_WARNING);
14            return FALSE;
15        } elseif ($responseCode < 200 || $responseCode > 300) {
16            $this->systemLogger->log(sprintf('Could not copy resource from "%s", got response code %d.', $uri, $responseCode), LOG_WARNING);
17            return FALSE;
18        }
19
20        // ...

But this breaks the unit tests with a warning

get_headers(): This function may only be used against URLs

What do you think about the general approach?
Actually it might be cleaner to switch to a proper request (maybe using Flows RequestEngineInterface) altogether here as copy() is pretty limited.

BTW: If we adjust this we could also think about changing the return value from object/FALSE to object/NULL as we do it in most places already