Strange or not, linux did not restore SS on sigreturn in 64 bit mode. The point of explaining that is to emphasize that the issue described in the blog post is not the only one in this code (the code doing entering / exiting signal handlers).
Okay, I read your post as meaning that it was still broken.
FWIW, I don't consider it sad that my first attempt was reverted. I inadvertently broke some assumptions that a real program (DOSEMU) was making, and Linux takes backwards compatibility quite seriously. The second version was better.
The issue is fixed indeed, as for Feb 17, 2016.