[Blender] UI graphical corruption with AMD/ATI open-source driver

Opening Blender (v2.79) this morning, after not running it for months, I noticed some serious glitches making Blender almost unusable.

Serious glitches on the interface

I have an old HD7750, using the open-source xf86-video-ati driver. It seems to be a bug within Blender, but fortunately there's a quick fix: change Window Draw Method to Triple Buffer in File -> User Preferences -> System.

Triple Buffer setting

The ArchWiki also notes that that setting may increase VRAM usage.