fix segfaulting when new text is smaller than the oldtext, m_start_pos has to be 0 before calculating anything else.
fix segfaulting when new text is smaller than the oldtext,
m_start_pos has to be 0 before calculating anything else.

naimdjon/fluxbox,luebking/fluxbox,luebking/fluxbox,olivergondza/fluxbox,lukoko/fluxbox,naimdjon/fluxbox,Arkq/fluxbox,lukoko/fluxbox,luebking/fluxbox,luebking/fluxbox,Arkq/fluxbox,naimdjon/fluxbox,olivergondza/fluxbox,luebking/fluxbox,lukoko/fluxbox,lukoko/fluxbox,olivergondza/fluxbox,olivergondza/fluxbox,naimdjon/fluxbox,Arkq/fluxbox,lukoko/fluxbox,naimdjon/fluxbox,olivergondza/fluxbox,Arkq/fluxbox,Arkq/fluxbox