TYPO3 Core

I'm running a TYPO3 v9.5.11 with an implementation of adaptive images which leads to a huge amount of processed files.

Additionally if have upscaling disabled:

$GLOBALS['TYPO3_CONF_VARS']['GFX']['processor_allowUpscaling'] = false;

So in many cases the original files should get rendered in fe without processing.

This change led to a performance slump, which was inexplicable to me.
During my research i have found some processed files in the database, which are updated on every request even if the page should be cached.

These entries have the following properties set:

identifier=''
name=null

After more search I came to bug #62400 which is "Rejected" and points me to the TYPO3\CMS\Core\Resource\ProcessedFile:

 * A file may also meet the expectations set in the configuration without any processing. In that case, the
 * ProcessedFile object still exists, but there is no physical file directly linked to it. Instead, it then
 * redirects most method calls to the original file object. The data of these objects are also stored in the
 * database, to indicate that no processing is required. With such files, the identifier and name fields in the
 * database are empty to show this.

Therefore, the existence of these entries is correct. But i think these properties should have the same value (null) in the database:

identifier=null
name=null

These files are always touched while the condition never matches in \TYPO3\CMS\Core\Resource\ProcessedFile::usesOriginalFile

public function usesOriginalFile()
{
    return $this->identifier === null || $this->identifier === $this->originalFile->getIdentifier();
}

or in \TYPO3\CMS\Core\Resource\ProcessedFile::updateWithLocalFile

if ($this->identifier === null) {
    throw new \RuntimeException('Cannot update original file!', 1350582054);
}

To fix this the database structure should get fixed.

The identifier is created like this:

identifier varchar(512) DEFAULT '' NOT NULL,

But the default should be NULL

identifier varchar(512) DEFAULT NULL,

Only in this case, the condition matches and the files are not constantly updated.