No, I don't think so. Anyway, the intention here is the same as for the favicon URLs in FeedBusinessLayer:
```<img src="test/img.jpg" />```
is converted by simple pie/feed fetcher to
```<img src="http://feedsite.com/test/img.jpg" />```
attachmentcaching saves the image and the html with
```<img src="/owncloud/../api../[feedID]/[itemID]/[somerandom]_img.jpg" />```

The owncloud domain is inserted on request in the ```convertRelativeImgUrls``` function.