Intention:
Replicate a mess seen at https://pt.wikipedia.org/w/index.php?title=Esporte_Clube_Pelotas&curid=68824&diff=38075497&oldid=38075466

Steps to Reproduce:

1. Start creating a new reference.
2. Open nytimes.com and select both some text and one small image.
3. Copy the selection and paste it into the ref dialog box.

Actual Results:
In Safari, nothing pastes. In Firefox, both text and image rich-paste into the ref dialog box, but I can't save the page.

Expected Results:
That the image would be discarded, since it's not uploaded to the wiki.

Reproducible: Sometimes

Version: unspecified
Severity: normal