File#filterFilename does not use FolderNameFilter

[sb-relaxt-at]

From my understanding the named method should use a FolderNameFilter when sanitizing the path (except for the last part if this is a file). But it uses a FileNameFilter for all parts of the path. Therefore a path like foo.bar/example.jpg will remain foo.bar/example.jpg although it should be (and will be later converted to) foo-bar/example.jpg

[sb-relaxt-at]

Something like this should work as getFilter() is overwritten in Folder to return a FolderNameFilter:

protected function filterFilename($name)
{
    // Fix illegal characters
    $filter = $this->getFilter();
    $folderFileFilter = FolderNameFilter::create();
    $parts = array_filter(preg_split("#[/\\\\]+#", $name));

    return implode('/', array_merge(
        array_map(function ($part) use ($folderFileFilter) {
            return $folderFileFilter->filter($part);
        }, array_slice($parts, 0, -1)),
        array_map(function ($part) use ($filter) {
            return $filter->filter($part);
        }, array_slice($parts, -1, 1))
    ));
}

[emteknetnz]

Do you know if this is causing any issues in the cms or on a website front end?

Would you like to raise a PR to fix this?