Created attachment 67908 [details]
Screenshot showing xterm cursor issue (missing lower-right pixel)
When using SNA instead of UXA in the xf86-video-intel driver, I see the following issues:
1) In an unfocused xterm window, where the block cursor is an empty rectangle, the lower right pixel is missing.
2) In Chromium, moving the mouse in a tab causes strange, blocky flickering of parts of the text in that tab.
Note that #1 also is mentioned in the following Arch Linux bug: https://bugs.archlinux.org/task/30983
I also filed a Gentoo bug here: https://bugs.gentoo.org/show_bug.cgi?id=436734 (Note that I originally thought this was version-dependent but later realized it was UXA/SNA-dependent)
From lspci: VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
I have attached a screenshot showing #1 above.
Two bugs, the first is definite and I expected to turn up at some point. But not in xterm, expecially when there is an explicit primitive for xterm to use there instead of manually drawing the outline!
The second bug needs a second report, and a lot more details since it is not something I have observed at all.
Agreed regarding "symtom #2". I had originally grouped these, since they showed up at the same time, but now that I realize both are SNA-related, it makes sense they are independent. Hard to get a screenshot of the second issue, since it fluctuates as the mouse moves, but I will submit a new bug and collect as much info as I can.
New bug created for symptom #2: https://bugs.freedesktop.org/show_bug.cgi?id=55500
Meh, I had it categorised as a different bug and was reserving it until I had the pleasure of reviewing the line drawing code.
Author: Chris Wilson <firstname.lastname@example.org>
Date: Tue Jan 22 09:24:04 2013 +0000
sna: Extend rectangular PolyLines to cover corner pixels on ccw paths
Reported-by: Joe Peterson <email@example.com>
Signed-off-by: Chris Wilson <firstname.lastname@example.org>
2.21.0 looks good.