Re: Bug#874054: Setting QT_LINUX_ACCESSIBILITY_ALWAYS_ON=1 has a huge negative performance impact, should not be always on

[Samuel Thibault <sthibault@debian.org>]

Samuel Thibault, on dim. 03 sept. 2017 20:23:30 +0200, wrote:
> Allan Sandfeld Jensen, on dim. 03 sept. 2017 20:19:31 +0200, wrote:
> > On Sonntag, 3. September 2017 19:57:55 CEST Samuel Thibault wrote:
> > > Allan Sandfeld Jensen, on dim. 03 sept. 2017 19:13:38 +0200, wrote:
> > > 
> > > That's Qt's fault for not taking care of EventListenerRegistered
> > > signals to determine whether someone is listening.
> > 
> > So it is Qt's fault that is doing what you have told it to do? You have set 
> > the environment variable to ignore the absence of listeners. That is what 
> > QT_LINUX_ACCESSIBILITY_ALWAYS_ON does.
> 
> Ah?  That's not what I had gotten in my tests.  I'll check again, then.

I have checked with a vanilla reinstall of Debian 9, using the Mate
desktop, and Qt 5.7.1.

When QT_LINUX_ACCESSIBILITY_ALWAYS_ON is not set, I don't see Qt
applications in accerciser, only the Mate applications. If I set
QT_LINUX_ACCESSIBILITY_ALWAYS_ON, I do see them.

On my current desktop, I have Qt 5.9.1, I made quick tests, it seems
it behaves as I expect, so perhaps we can indeed avoid setting
QT_LINUX_ACCESSIBILITY_ALWAYS_ON now. I'll retest with a vanilla
reinstall of debian testing, to be sure.

Samuel