Steps to reproduce:

1. https://nl.wikipedia.org/wiki/Dolichognatha_petiti?veaction=edit
2. Click on infobox and edit translusion
3. In the first parameter (afbeelding), add 'blah', and apply changes
4. 'Save' & 'Review your changes'

Result:

-| afbeeldingtekst =
+| afbeelding =
+blah| afbeeldingtekst =

Expected results:
-| afbeelding =
+| afbeelding = blah

p.s. [[nl:Dolichognatha petiti]] is currently on the parsoid topfail list
http://parsoid.wmflabs.org:8001/topfails/15

Regarding the actual bug, I saw a similar diff ~20 hrs ago:
https://en.wikipedia.org/w/index.php?title=List_of_Sam_%26_Cat_episodes&curid=39469556&diff=565437324&oldid=565416618

Version: unspecified
Severity: normal