Document with a zero-sized graphic - how to handle?

Hi all, 

Bug 92157 has uncovered something interesting. 

Someone with the email address libreoffice at arbruijn.dds.nl found the following:

> I've investigated the problem for this document, and it's that the document has a graphic with 
> size 0, 0. (It contains the xml <a:graphic...<a:xfrm><a:off x="0" y="0"/><a:ext cx="0" 
> cy="0"/></a:xfrm>). This fails the test in SwFormatFrmSize::PutValue (MID_FRMSIZE_SIZE) which 
> makes SfxItemPropertySet::setPropertyValue throw an IllegalArgumentException, aborting the parser.

He/she gave us a patch which Mike Kaganski added to Gerrit here: 
https://gerrit.libreoffice.org/21287

I’ve merged this, as it fixes a legitimate issue. However, I’d like to ask on the list, just to 
double-check - how *should* we deal with images of size 0x0? According to a comment from Mike, the 
standard doesn’t impose a restriction on this, so it appears to be valid. 

Are we happy to keep skipping setting the graphic size if the graphic is zero-sized? One 
interesting thing highlighted is that a 0x0 image might be being used as a tracker. 

Is it worthwhile logging another bug to handle the possible tracking aspect? i.e. if there is a 
zero sized image in the document that we grab directly from a website, then there is a good 
likelihood that it’s a tracker and in this case, is it worthwhile us not getting it? 

Anyway, committed this patch in 
https://cgit.freedesktop.org/libreoffice/core/commit/?id=654f6ff28d7a148950b48ed8905d8f13a015a5b5

Also wondering if it might be worthwhile back-porting?

Chris