Comment 170 for bug 1098489

Well I'm curious how this explains this - I've taken current git -
changed the value to '44' - and I'm typing this text. I could see a lot of errors during text typing - but these errors seems to be somehow limited only to certain regions of shown text.

It's not destroyed everywhere - only in some particularly piece and in particular time - it's kind of weird defect to observe - and it also happen for only some specific use-case

i.e. my text edit 'fte' which is using X drawing code has absolutely no issue - all characters are always correct.
But in firefox - typing this BZ I could see a lot of changing letters (usually everything after 10 letter on the line is weirdly changing - like if the font cache would be not working correctly.

Typing on keyboard shows rending bugs - as soon as right mouse button is hit - everything is instantly redrawn correctly and pop window is shown.

Another thing I notice is - I've about 20 lines of email headers in thunderbird. And exactly only the 4th line is showing problems with letters - even when I just move the mouse over the TB window - this text is being continuously modified - but everything else in that window is without any problem.

So if you say - there is hw bug - how is that - it could very easily render everything correctly ?

Why only certain portions of text have distortions - why it's not randomly spread over the whole screen (which I'd have expected for time collisions)?