Less confusing variable name.

Change-Id: I8a6c9a037b3863d913583f5be3d7c0c6b96f29f8
bnc#830205: Stop-gap solution to avoid crash.

This improves the situation, because previously, the document would just crash
due to infinite recursion.

Deeper checking why do we end up with an invalid range would be good; but it
was impossible to check with the bugdoc, as it was too complex, and trying to
cut it down was crashing MSO :-)  Hopefully we'll get a better document at
some stage.

Change-Id: I4cd639e02aebe9027f06e8468c14969c506327b2