Hello,

when ‘TeX-quote-after-quote’ is nil, ‘TeX-insert-quote’ fails when
called from a position closer to the beginning of buffer than the
length of an opening quotation mark. That’s due to a ‘forward-char’
trying to go back to see if the thing preceding the point is an
opening quote.

To reproduce the bug, open a buffer in ‘LaTeX-mode’, type a character
and invoke ‘TeX-insert-quote’. It just prints the message “Beginning
of buffer” without inserting anything.

I think it’s reasonable to insert an opening quote whenever there
isn’t room for one behind the point. I’ve attached a patch that
implements this behaviour.

All the best,
Andrea