Plasma-desktop bug, desktop completely black but still able to open windows

[Duncan]

Britt Mathis posted on Thu, 21 Mar 2013 13:29:20 -0400 as excerpted:

> This is my first post to a mailing list ever, so I apologize in advance
> if this has already been resolved or I am in violation of post etiquette
> in some way.

FWIW, your post was quite good, with one exception.  Good: You included 
the kde version, a reasonable description of the problem, and what you'd 
done to narrow it down and/or try to fix it yourself (start plasma from 
the command line, etc).  You'd be surprised at the number of people who 
include no version information at all, or if they do, it's for some 
distribution (not for kde) that others may or may not be at all familiar 
with.  That's always frustrating as it's so simple to include, but takes 
another round of question and reply to get when it's not included, and 
there's often several rounds of that as it is.

Single bad point:  Many list regulars have been working with computers 
for quite some time, and are traditional enough to consider HTML messages 
bad form, at minimum.  I do, but also realize that a lot of people don't 
even know they're posting in HTML in the first place, until someone 
requests they don't.  (Sometimes people who don't even like HTML 
themselves end up posting in it themselves, if they're running a mailer 
that defaults to HTML and "forgets" their preferences, and I get thanked 
for pointing it out so they can fix it, so it's easy enough to do.)  From 
this perspective, if it has to be dressed up in HTML to be worth reading, 
it's not worth reading at all, and the people who post in HTML can be 
broken down into four camps:  The spammers, who often use HTML to hide 
some of their filter avoidance tricks, the malware folks (often a spammer 
subtype), who use it to obfuscate links and try to trick people, and/or 
to track readership without permission (web bugs), and/or to exploit a 
known security vuln in some HTML parsing mail client or other, the people 
who simply don't realize the problem or that they're doing it, and the 
rude folks who simply don't care.  Fortunately, many people are in the 
third category and only need it pointed out and they stop.  After all, 
irritating the folks who might have your answer isn't generally a good 
idea.

(FWIW, your post had two portions, an HTML and a plain text portion.  But 
had I been kill-filing all HTML messages as some do, I'd have never seen 
the message and thus would have never replied...)

> I am running KDE 4.10.1. Every time I customize the desktop and reboot,
> I still get the splash animation, but I am booted into a completely
> black screen. I am then able to use kRunner to open any application and
> the applications function normally. As far as I can tell this is
> specifically affecting plasma.

Yes.  KDE is deliberately modularized enough so that barring either two 
different bugs or a single bug so bad it affects both, you'll always have 
either krunner or plasma available to launch other apps with, even if the 
other one has crashed, as plasma seems to be doing in your case.

> When I try starting plasma for the command line, I get a lengthy error
> message (I can replicate this bug and post an exact message if you all
> would like). The main error is an X error, BadPixMap invalid parameter -
> 4.

Unfortunately, much of kde appears to be designed with the assumption 
that nobody but the developers runs anything from the command line or 
with STDOUT/STDERR redirected to a file in ordered to try to debug 
problems.  As a result, when run from the command line or with STD* 
captured, kde apps routinely spit out a huge amount of alarming looking 
but non-fatal "noise" that's arguably of interest to the devs themselves, 
but is just that, noise, to a power user or admin trying to debug a 
problem, but who now can't see the real problem due to the volume of 
"normal" messages, now noise hiding the signal of worth that he's trying 
to find!

> I googled this and didn't really get anything recent. I have managed to
> isolate this bug to when I resize my panel or when I add too many icons
> to my panel. Everything else survived rebooting several times.
> 
> I appreciate any help you guys can give me. Again, I apologize if this
> has already been resolved.

Here's a few hints, anyway:

1) Important!  Please backup your $KDEHOME/share/config/plasma-desktop-
appletsrc file.  ($KDEHOME defaulting to ~/.kde or sometimes ~/.kde4, 
depending on distro.)  If this file gets corrupted, you lose all the 
customizations you have and may need to start from the defaults, as while 
it is a text-based file, it's too complex to /easily/ edit by hand.  At 
least having a backup will let you easily restore it if necessary.  I've 
had to do that a few times here.

2) With the backup made and plasma not running, try deleting the above 
file and see if you can then successfully reconfigure plasma.  If so, 
it's a problem in the existing file.

3) Try temporarily turning off desktop effects.  Sometimes they are the 
problem, but can be reenabled after the desired adjustment has been made.

Gotta head to work now.  Later!
-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

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