Manually setting the time into the past makes flickables misbehave

[Allan LeSage]

Unexpected behavior while testing a U1 silo:

TEST CASE
1. Open ubuntu-system-settings, set time manually into the past a few hours
2. Return to scopes
3. Swipe left for next scope
EXPECTED
Scope swipes left, next scope appears.
ACTUAL
Stunted swipe appears to register late, fails to switch scope.

Please feel free to reassign if the gesture itself is dependent on time? Pathological use case but maybe worth examining if it exposes some pathological codepaths ;) .

[dobey (dobey)]

Should not this bug be filed against Unity8? I noticed in testing the other day that Unity8 was particularly slow on my mako, but the update the next day returned the behavior to normal. My time has been set to be off by a month for several days now, so I don't think that's the issue. I didn't file a bug against Unity8 though, since the issue went away for me. It was painful to even just scroll the results in the current scope for me, when it happened. Perhaps this is more related to the smooth updates changes?

[Allan LeSage (allanlesage)]

Ok I do think this is a real issue, happy to post a video--I've been testing a release on this arale and was confused when seeing this behavior again after a fresh flash.

I previously set the time manually on this phone--I assume this persists in some way in hardware, because the time is incorrect on boot even after flashing. So, the phone wakes displaying an incorrect time; if I'm able to get through lock quickly, I see the indicator changing to NTP. When the indicator changes to the correct time *the sluggish behavior turns on* <terrifying music>.

Still trying to lock down the conditions to reproduce this bug wanted to report.

[Allan LeSage (allanlesage)]

Here's a video demonstrating swiping behavior, also that launcher and spread are available: http://people.canonical.com/~alesage/video20151210_131623833.mp4 .

[Albert Astals Cid (aacid)]

I don't think it's an unity8 bug since other apps (e.g webbrowser or just this QML snippet http://paste.ubuntu.com/14003581/ ) have the same problem.

I guess something is storing timestamps somewhere and timestamps being in the past makes things unhappy.

[Launchpad Janitor (janitor)]

This bug was fixed in the package qtmir - 0.4.7+16.04.20160212-0ubuntu1

---------------
qtmir (0.4.7+16.04.20160212-0ubuntu1) xenial; urgency=medium

  [ Albert Astals Cid ]
  * Provide branch prediction information to the if in compressTimestamp
  * Reset start time if the timestamp travels to the past (LP: #1524488)

  [ Daniel d'Andrada ]
  * Let shell decide the initial surface size (LP: #1532974)
  * Remove the useless TaskController
  * Surface Size Hints
  * Update mir version requirement

  [ Michał Sawicz ]
  * Bump unity-api dependencies
  * Use QStandardPaths to determine QML cache location

  [ Nick Dedekind ]
  * Moved test framework into a static library for quicker
    recompilation.

 -- Michał Sawicz <email address hidden> Fri, 12 Feb 2016 00:07:26 +0000