[Kde-bindings] QtRuby crashes

[Sebastian Sauer]

If we are using QtRuby embedded in an application using Kross, we keep to get 
crashes on application exit. The backtrace looks like;

[KCrash handler]
#5  0x00002aaac1b56a86 in QHashNode (this=0x13fed20, key0=@0x70, value0=@0x78)
    at /home/kde4/qt4-copy/include/QtCore/qhash.h:186
#6  0x00002aaac1b56bb5 in QHash<void*, unsigned long*>::duplicateNode (
    node=0x60, newNode=0x13fed20)
    at /home/kde4/qt4-copy/include/QtCore/qhash.h:473
#7  0x00002aea9e100672 in QHashData::detach_helper (this=0x2645510, 
    node_duplicate=0x2aaac1b56b66 <QHash<void*, unsigned 
long*>::duplicateNode(QHashData::Node*, void*)>, nodeSize=32) at 
tools/qhash.cpp:184
#8  0x00002aaac1b586ac in QHash<void*, unsigned long*>::detach_helper (
    this=0x2aaac1d9d580) at /home/kde4/qt4-copy/include/QtCore/qhash.h:535
#9  0x00002aaac1b58716 in QHash<void*, unsigned long*>::detach (
    this=0x2aaac1d9d580) at /home/kde4/qt4-copy/include/QtCore/qhash.h:253
#10 0x00002aaac1b587d3 in QHash<void*, unsigned long*>::remove (
    this=0x2aaac1d9d580, akey=@0x7fff0ce38100)
    at /home/kde4/qt4-copy/include/QtCore/qhash.h:730
#11 0x00002aaac1b555cf in unmapPointer (o=0x2533aa0, classId=260, 
    lastptr=0x235b8d0)
    at /home/kde4/svn/_src/KDE/kdebindings/ruby/qtruby/src/Qt.cpp:262
#12 0x00002aaac1b62c02 in smokeruby_free (p=0x2533aa0)
    at /home/kde4/svn/_src/KDE/kdebindings/ruby/qtruby/src/handlers.cpp:347
#13 0x00002aaac165bd8e in rb_gc_call_finalizer_at_exit ()
   from /usr/lib/libruby1.8.so.1.8

I did investigate this a bit during hours of testing, I did note that the 
QHash<void *, VALUE *> pointer_map; defined within Qt.cpp does got invalid 
while cleanup. It seems for whatever reason the internal Node* instances got 
partly lost somewhere at the shutdown and therefore it keeps to crash. Even a 
simple foreach(Value*, pointer_map); could trigger this. During testing I 
even got a more useful backtrace that shows, that something goes totaly 
wrong;

[KCrash handler]
#5  0x00002b8da35e1765 in raise () from /lib64/libc.so.6
#6  0x00002b8da35e31c0 in abort () from /lib64/libc.so.6
#7  0x00002b8d98c43e48 in qt_message_output (msgType=QtFatalMsg, 
    buf=0x7fff122cf400 "ASSERT: \"*node == e || (*node)->next\" in 
file /home/kde4/qt4-copy/include/QtCore/qhash.h, line 826") at 
global/qglobal.cpp:2145
#8  0x00002b8d98c43f69 in qFatal (
    msg=0x2b8d98d324f8 "ASSERT: \"%s\" in file %s, line %d")
    at global/qglobal.cpp:2376
#9  0x00002b8d98c440bd in qt_assert (
    assertion=0x2aaac5bba193 "*node == e || (*node)->next", 
    file=0x2aaac5bba168 "/home/kde4/qt4-copy/include/QtCore/qhash.h", 
line=826)
    at global/qglobal.cpp:1904

The following "patch" fixes this 100% and no crashes do popup any longer (yes, 
I know that the solution may suck cause a lookup now may take longer, but at 
least it does not crash any more :)

Index: src/Qt.cpp
===================================================================
--- src/Qt.cpp  (revision 731455)
+++ src/Qt.cpp  (working copy)
@@ -94,7 +94,7 @@
 int do_debug = qtdb_none;
 #endif

-QHash<void *, VALUE *> pointer_map;
+QMap<void *, VALUE *> pointer_map;
 int object_count = 0;

 QHash<QByteArray, Smoke::Index *> methcache;