Menu interaction in fully maximised window causes the next click on the title bar to restore the window (after 2^31ms of uptime)

This only happens after the system has been running for a while, so either a long running service stops behaving correctly or a software upgrade causes it to stop working correctly. I logged in as a Guest Session and the problem still occurred, but it doesn't happen immediately after a reboot.

Even restarting Xorg doesn't fix this, only a reboot resolves it.

com/canonical/unity/integrated-menus/double-click-wait is set to the default (0ms)

If I set it to 300ms, then menu opening is delayed by 300ms but step 6 (The window restores to non-maximised size) occurs immediately upon clicking as soon as the button is pressed (even if it is not released).

This is a bug in libnux-4.0-0 on amd64, caused by the code in GraphicsDisplay::MousePress (NuxGraphics/GraphicsDisplayX11.cpp) which converts the unsigned long timestamp to a signed int:

if ((double_click_counter_ == 1) && ((int)current_time - (int)last_click_time_ < double_click_time_delay))

The timestamp is in milliseconds, so it becomes negative after about 24.86 days.

The comparison works ok until the final click on the title bar, when last_click_time_ is 0.
Subtracting 0 from the negative current_time results in a value that is always less than double_click_time_delay.
The unnecessary cast to int should be removed.

Version:
libnux-4.0-0 4.0.7+14.10.20141007-0ubuntu1

The bug affects unity via compiz (which uses libnux).

Version:
compiz 1:0.9.12+14.10.20140918-0ubuntu1

Simon: excellent work. I have a particular fondness for reading the write-ups on this time of bug. It reminds me a little of the infamous "Doesn't print on Tuesdays" (bug #248619).

Once again, kudos to gradually narrowing down how to replicate it, then finding it and finally offering the patch.

The attachment "Patch for nux-4.0.7+14.10.20141007" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

This bug was fixed in the package nux - 4.0.7+15.10.20150802-0ubuntu1

---------------
nux (4.0.7+15.10.20150802-0ubuntu1) wily; urgency=medium

  [ CI Train Bot ]
  * New rebuild forced.

  [ Simon Arlott ]
  * fix the size of timeout values on 64-bit platforms (thanks Simon
    Arlott) (LP: #1379960)

  [ Stephen M. Webb ]
  * fixed a FTBFS when using GCC-5

 -- CI Train Bot <email address hidden> Sun, 02 Aug 2015 14:35:23 +0000