Bug 368138

Summary:	Kdevelop hangs at start and uses one cpu at 100% when started with high dpi settings
Product:	[Applications] kdevelop	Reporter:	Michael Tils <nospam>
Component:	UI: toplevel window	Assignee:	kdevelop-bugs-null
Status:	RESOLVED FIXED
Severity:	crash	CC:	bruno
Priority:	HI
Version:	5.0.0
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:	5.0.1

Description Michael Tils 2016-09-02 07:37:08 UTC

If I start kdevelop on my external screen (with 120x120dpi) it starts normal and I can work with it. If I try to start it on my internal laptop monitor (with 192x193dpi) it hangs and uses one cpu at 100%.

As a test I started kdevelop with Xephyr using different dpi values:

Doesnt work:
Xephyr :1 -ac -dpi 192 -screen 1480x1680 &; DISPLAY=:1 kdevelop

Does work:
Xephyr :1 -ac -dpi 96 -screen 1480x1680 &; DISPLAY=:1 kdevelop

I tried a few resolutions, it seems that the highest working value is 164 DPI. Any start of kdevelop with a setting above 164 DPI will cause kdevelop to hang at start. When I test it here in Xephyr I can see it instantly. If it hangs, I can not select any Text in its Editor or klick somewhere.

Reproducible: Always

Steps to Reproduce:
1. Xephyr :1 -ac -dpi 192 -screen 1480x1680 &
2. DISPLAY=:1 kdevelop

Actual Results:  
Kdevelop hangs and cant receive input

Expected Results:  
It does not hang

Comment 1 Kevin Funk 2016-09-02 19:47:17 UTC

Can you try the following:
export KDEV_DISABLE_WELCOMEPAGE=1
kdevelop 

Does it still hang then for the 164 DPI setting?

Comment 2 Michael Tils 2016-09-03 07:29:40 UTC

With:

KDEV_DISABLE_WELCOMEPAGE=1 kdevelop

it does not hang with 192DPI or 180DPI (I didnt try so many) so it seems to solve the problem. The problem (without your fix) did show when I started Xephyr with > 164 DPI, so I had to test it with values > 164 (just for clarification)

Does a welcome screen (which I never saw again in this kdev session) prevent kdevelop to start properly?

Comment 3 Kevin Funk 2016-09-03 14:49:03 UTC

Yes, we had a few problems with the Welcome Page in the 5.0.0 release. This should be fixed for the upcoming 5.0.1, though.

Related patches: https://phabricator.kde.org/D2581

Another commit:
commit 29d302ec5955ab0aec240ced6302247d903dc81a
Author: Kevin Funk <kfunk@kde.org>
Date:   Sat Sep 3 01:50:51 2016 +0200

    WelcomePage: Fix another buggy binding

Comment 4 Michael Tils 2016-09-03 14:54:07 UTC

Thanks a lot for your very (and I mean really fast) responses :-)
I never saw a commercial support as good as you.

Thanks for your great work. I use kdevelop for python and php development and I know exactly why I not use PHPStorm or PyCharm ;-)

Comment 5 Kevin Funk 2016-09-13 11:54:48 UTC

*** Bug 368731 has been marked as a duplicate of this bug. ***