[gtkmm] textbuffer's signal_erase

[gagnon WPI EDU]

I've been trying to add undo/redo support to a project of mine. I used a
signal handler connected to signal_insert() and it worked fine to add any
insertions to the undo/redo stack. When I tried to do the same with
signal_erase() I ran into a problem. From what I can tell, the text is
deleted before the signal handler is called, so that the two iterators
passed into the handler are at the same spot. Now matter how I delete the
text, or how much I delete, my program thinks I deleted "". Is this
stupidity on my part or a bug in gtkmm?