Ah okay, I had not found the CTRL + drag for column select. That is half of what I was thinking. But the main part, is the ability to select a zero-width column of lines, begin typing and have the text appear on every line selected. Thinking about it, it's possible to overwrite a selected block in this manner too. Maybe this is what the SVN changes support, it's a hard feature to put a name to...
2007-03-30 08:34:02 UTC in Geany