Help with bug #51395

Sat Dec 14 22:09:51 GMT 2002

I'm trying to fix bug #51395 (http://bugs.kde.org/show_bug.cgi?id=51395).
Unfortunately, the problems are a little out of my league, so if anyone can 
help me, I'd appreciate it.

I had encountered problems similar to the user who reported the bug. My stack 
trace was different, however, and after some debugging, I discovered that if 
the "location" setting of katerc's [fileselector] group points to a 
non-existent path, then I get a crash. This is because kate attempts to set 
the path using KURL, which throws up a message box if it can't find the path. 
The message box then blocks the user interface (I think) and causes the crash 
when kate attempts to show its main window.

This is probably a bug in KURL because I don't think it should be responsible 
for displaying error messages. The applications calling KURL should be the 
ones checking for return codes or exceptions and putting up error messages as 
needed.

I can't be certain of that, so instead I patched kate. The problem can be 
fixed by changing the line in kdebase/kate/app/katefileselector.cpp so that 
if the path doesn't exist, the user's home path is used. A diff is attached. 
Feel free to apply after review.

I'm surprised nobody else has encountered this bug, since it would seem very 
easy to duplicate. All you have to do is run kate, exit, delete whatever 
directory kate was looking at, then restart kate. (I haven't verified this, 
though.)

Anyway, the big problem I'm having is with another bug that I discovered after 
fixing the one above. This bug (stack trace attached) is also likely due to 
an improper katerc because the crash seems to occur in 
kdelibs/kdeui/kdockwidget.cpp on line 2356, where the dock settings are 
loaded. The "c->readNumEntry" call returns 1, which is then passed to 
tab->page, which never returns because of the crash. I get lost trying to 
figure out what's happening here, mostly because I don't understand how kate 
loads the dock settings and displays the tabs. (I've never worked with Qt tab 
widgets before.)

I hope someone can shed some light on what's happening here - or even better, 
post a patch! I've attached my katerc, which should allow reproduction of the 
bug.

Thanks,

Trevor

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[New Thread 8192 (LWP 29624)]
0x420ae169 in wait4 () from /lib/i686/libc.so.6
#0  0x420ae169 in wait4 () from /lib/i686/libc.so.6
#1  0x4212a2d0 in __DTOR_END__ () from /lib/i686/libc.so.6
#2  0x41062c63 in waitpid () from /lib/i686/libpthread.so.0
#3  0x4070a549 in KCrash::defaultCrashHandler(int) (sig=11) at kcrash.cpp:235
#4  <signal handler called>
#5  0x40d6af39 in QGList::locate(unsigned) (this=0x5b000000, index=1)
    at tools/qglist.cpp:322
#6  0x40a8db05 in QGList::at(unsigned) (this=0x5b000000, index=1)
    at ../include/qglist.h:168
#7  0x40c040cf in QPtrList<QTab>::at(unsigned) (this=0x5b000000, i=1)
    at ../include/qptrlist.h:88
#8  0x40c02b74 in QTabBar::tabAt(int) const (this=0x40083be0, index=1)
    at widgets/qtabbar.cpp:942
#9  0x40c076fe in QTabWidget::page(int) const (this=0x8170728, index=1)
    at widgets/qtabwidget.cpp:906
#10 0x405a0eda in KDockManager::readConfig(KConfig*, QString) (this=0x812d938, 
    c=0x8052c28, group=) at /opt/qt/include/qstring.h:933
#11 0x405956f9 in KDockMainWindow::readDockConfig(KConfig*, QString) (
    this=0xfffffe00, c=0x0) at kdockwidget.cpp:169
#12 0x400687fb in KateMainWindow::readOptions(KConfig*) (this=0x8118a78, 
    config=0x8052c28) at katemainwindow.cpp:422
#13 0x4006547f in KateMainWindow (this=0x8118a78, _m_docManager=0xfffffe00, 
    _m_pluginManager=0xfffffe00, projectMan=0xfffffe00)
    at katemainwindow.cpp:143
#14 0x40052b50 in KateApp::newMainWindow() (this=0xbffff700) at kateapp.cpp:204
#15 0x400517bf in KateApp (this=0xbffff700, forcedNewProcess=false, 
    oldState=false) at kateapp.cpp:68
#16 0x40014324 in main (argc=1, argv=0xbffff8b4) at katemain.cpp:106
#17 0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6
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[General]
Opaque Resize=true
Show Console=false
Show Full Path in Title=false
Sync Konsole=true

[KFileDialog Settings]
Automatic Preview=true
Recent Files=/home/trevor/ipaq/article/code/code/servo-controller/servo-controller.c,/home/trevor/african-friends/african-friends-broadband.ram,/home/trevor/african-friends/african-friends-dialup.ram,/home/trevor/possible source of connections to sponsors for ghana dance group.txt

[KFileDialog Speedbar]
Speedbar IconSize=32

[KateDock::bottomDock]
widget0=DOCKconsole

[KateDock::leftDock]
widget0=DOCKfilelist
widget1=DOCKoperator

[MainWindow]
Height 1050=958
MenuBar=Enabled
StatusBar=Enabled
Width 1400=1393

[MainWindow Toolbar mainToolBar]
Hidden=false
IconSize=22
IconText=IconOnly
Index=0
NewLine=false
Offset=-1
Position=Top

[Recent Files]
File1=file:/home/trevor/ipaq/article/code/code/servo-controller/readme.html
File10=file:/home/trevor/short_dld2.html
File2=file:/home/trevor/ipaq/article/code/code/servo-controller/servo-controller.c
File3=file:/home/trevor/ipaq/article/code/code/servo-controller/Makefile
File4=file:/home/trevor/ipaq/article/servo-controller.c
File5=file:/home/trevor/embarrassing teaching moments
File6=file:/home/trevor/african-friends/index.html
File7=file:/home/trevor/arttoday/get-wmf
File8=file:/home/trevor/get-wmf
File9=file:/home/trevor/short_dld.html

[TipOfDay]
RunOnStart=false

[dock_setting_default]
DOCKconsole:geometry=0,0,1111,694
DOCKconsole:stayButton=false
DOCKconsole:type=NULL_DOCK
DOCKconsole:visible=false
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:first_name=DOCKfilelist,DOCKoperator
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:last_name=mainDock,DOCKconsole
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:orientation=1
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:parent=yes
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:sepPos=20
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:stayButton=false
DOCKfilelist,DOCKoperator,mainDock,DOCKconsole:type=GROUP
DOCKfilelist,DOCKoperator,mainDock:first_name=DOCKfilelist,DOCKoperator
DOCKfilelist,DOCKoperator,mainDock:last_name=mainDock
DOCKfilelist,DOCKoperator,mainDock:orientation=1
DOCKfilelist,DOCKoperator,mainDock:parent=yes
DOCKfilelist,DOCKoperator,mainDock:sepPos=20
DOCKfilelist,DOCKoperator,mainDock:stayButton=false
DOCKfilelist,DOCKoperator,mainDock:type=GROUP
DOCKfilelist,DOCKoperator:curTab=1
DOCKfilelist,DOCKoperator:parent=yes
DOCKfilelist,DOCKoperator:stayButton=false
DOCKfilelist,DOCKoperator:tabNames=DOCKfilelist,DOCKoperator
DOCKfilelist,DOCKoperator:type=TAB_GROUP
DOCKfilelist:stayButton=false
DOCKfilelist:type=DOCK
DOCKoperator:stayButton=false
DOCKoperator:type=DOCK
Main:Geometry=0,0,1393,958
Main:dock=mainDock
Main:view=DOCKfilelist,DOCKoperator,mainDock
Main:visible=true
NameList=mainDock,leftDock,rightDock,topDock,bottomDock,DOCKfilelist\\,DOCKoperator,DOCKfilelist\\,DOCKoperator\\,mainDock
Version=0.0.5
bottomDock:geometry=0,0,700,33
bottomDock:stayButton=false
bottomDock:type=NULL_DOCK
bottomDock:visible=false
leftDock:geometry=0,0,24,418
leftDock:stayButton=false
leftDock:type=NULL_DOCK
leftDock:visible=false
mainDock,DOCKconsole:first_name=mainDock
mainDock,DOCKconsole:last_name=DOCKconsole
mainDock,DOCKconsole:orientation=0
mainDock,DOCKconsole:parent=yes
mainDock,DOCKconsole:sepPos=20
mainDock,DOCKconsole:stayButton=false
mainDock,DOCKconsole:type=GROUP
mainDock:stayButton=false
mainDock:type=DOCK
rightDock:geometry=0,0,88,85
rightDock:stayButton=false
rightDock:type=NULL_DOCK
rightDock:visible=false
topDock:geometry=0,0,114,65
topDock:stayButton=false
topDock:type=NULL_DOCK
topDock:visible=false

[fileselector]
AutoSyncEvents=0
current filter=
dir history=/home/trevor/arttoday/,/home/trevor/african-friends/,/home/trevor/ipaq/article/code/code/servo-controller/
filter history=
filter history len=9
last filter=
location=/home/trevor/arttoday/lkasjdl
pathcombo history len=9

[fileselector:dir]
Separate Directories=false
Show Preview=false
Show hidden files=false
Sort by=Name
Sort case insensitively=true
Sort directories first=true
Sort reversed=false
View Style=Simple