Bug#766849: gnome-shell responds and renders hazardously

[dAgeCKo]

Package: gnome-shell
Version: 3.14.0-1
Severity: critical
Debian: Testing amd64
Regression: Yes
gnome-session: 3.14.0-2

_Sometimes_ (it seems it is a constant for gnome-shell bugs), the 
response to the user actions and the rendering happens hazardously: the 
user action might not be taken into account (keybord, mouse move or 
clock) and the graphics might not be updated, or not well updated, 
resulting for the end user to do wrong actions. This is very grave since 
we can 'think' doing the good action, but wrongly. We can then loose 
data, corrupt them, or even a full system. Note that all programs 
happening under gnome-shell are subject to these bugs.

Please note that this has nothing to do with other upper programs (like 
xorg or gtk and so on) since there is no user-input or rendering issues 
under XFCE for example.

First example: Trying to write an email threw icedove under gnome-shell 
can be very painful. Sometimes, characters are not displayed, I must do 
another input action so that the enter character might be displayed.
This is the same for mouse actions: scrolling the window, clicking... 
can become the worst hardwork ever met on Debian ever.

Another example: launching a terminal under gnome-shell (ie xterm, 
because gnome-terminal is even worst), and using aptitude can be 
completly hazardous to the user point of view. Going up or down might 
look like it did not work, resulting in installing/uninstalling/updating 
unwanted programs. Or a sub-tree might not be displayed...

Another example: surfing on the internet with iceweasel might also be 
completly hazardous or slow looking. Pages might be rendered with waves 
(portions of the page might be moving, or not updated), clicking on a 
tab might not work and refreshing the page, might even not resolves the bug.

Last example: moving threw the virtual desktops (ctrl-alt-up or down) 
might display half of the previous desktop and half of the next one. 
Generally, with this bug, ctrl-alt-f1 and ctrl-alt-f7 might resolve the 
issue.

Also note that I tried to take some screenshots threw the print-screen 
key, but this refreshes the screen, so all my attempts resulted in a 
good looking image...

Finally, note that this is really critical because I already lost 
important data. This bug started several versions ago, but newer never 
resolved it (am I really the only one having this issue ?).
Also, this makes me wonder why gnome-shell 3.14 entered testing since it 
is completly unstable and could provoke critical results.