Obscure bug when deleting text

[mjomble]

Version: 3.1.6 (build 10721)

And by obscure I really mean it. Any deviation from the tiniest detail may result in the bug not occurring (yet it somehow did for me a few times during regular use):

* Open a comparison with the attached text file on the right side (the other file can just be empty)
* Scroll down several screenfuls
* Start selecting text from near the bottom of the screen. Move the mouse upwards and to the left pane while scrolling up with the mouse wheel.
* Once you're up several screenfuls, release the mouse.
* Move the mouse downwards and back to the right pane while scrolling down with the mouse wheel until you get to somewhere in the middle of the selection.
* Press the delete key on the keyboard.
* Occasionally, something goes wrong with updating the display and some of the deleted lines will be shown as selected instead of the actual content at that location.
* If you force refresh the display of those lines (by scrolling, for example), they go back to normal.

I also recorded a video of it in case it's difficult to reproduce:

http://justas.ggcmedia.com/bc3bug.avi

[Aaron]

Thanks for the steps and test files. I believe you are running into an odd painting issue (hence why scrolling, or a refresh will solve it).

I'll investigate and let you know what we find.