emacs won't repaint buffer (windows 7)

Question

I am using GNU Emacs 24.2.1 on 64-bit Windows 7. Sometimes emacs window goes blank. This usually happens when switching focus back to emacs from another window. The only way to get the content back is to switch to another buffer and then back. No other programs behave like this. I do not have this problem on my home PC with similar hardware and OS.

Bird

Your question is tagged emacsw32. Are you using the patched build? – Corsiglia

@Corsiglia I tagged it so only because "For questions specifically related to running Emacs on Windows". No other reason. – Bird

ah. I asked because EmacsW32 is also the name of an emacs distribution that includes modifications for Windows. Anyway, I think I've experienced what you're describing, but you'd have to narrow down when it occurs. – Corsiglia

Does M-x redraw-display make the problem disappear? You may also try to update to Emacs 24.3. A Windows build has been released recently. – Orientalize

It does. Thanks, this is better than switching buffers. I suspect the problem is with emacs-OS-GPU interaction (otherwise there would be more people complaining), but I will try updating anyway. – Bird

This is still happening on version 25.1.1 in 2017. The workaround is not a fix. Is there any real fix or a bug tracking this that is being worked on? – Giulio

Answer 1

I added the following code to my init.el so that when it happens to me (in 24.4), I just need to press F5:

(global-set-key (kbd "<f5>") #'redraw-display)

Silesia

(with GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601) of 2013-03-17 on MARVIN) This is a great improvement over my previous practice of minimising (C-z), then restoring (mouse click) emacs, which was quicker than M-x redraw-display, but multiple redraws are often required to get a stable display. Is there a newer emacs which is less affected by this problem (which seems to be related to Windows display code - sometimes it's better after an update, sometimes much worse.) – Timms