title: QObject::installEventFilter(): Cannot filter events for objects in a different thread
body: <p>I'm getting this error <code>QObject::installEventFilter(): Cannot filter events for objects in a different thread</code>. I have read that this error may arise when doing GUI operations not in main thread but in another thread. But my program is single threaded. I has one QMainwindow. Also I never install any event filters. Maybe Qt creates some other threads or event filters? I cant post the code because it is very huge and I dont know from where the error comes to post that part. <strong>So my question is how can I get more information about the error?</strong> Can I know exactly what does Qt try which cause the error. Also the error has random character: sometimes it is the error message, sometimes is <code>Bus error</code>, sometimes <code>segmentation fault</code> and sometimes there is not any problem.</p>
  
  <p>With GDB I get the stack but the only source is main.c where is called application.exec(), the other frames are Qt libs</p>
  
  <pre><code>0  0x0000002a969983bc in QObject::installEventFilter () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  1  0x0000002a9625a75d in QAbstractItemView::commitData () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  2  0x0000002a96991d58 in QMetaObject::activate () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  3  0x0000002a9640404f in QAbstractItemDelegate::commitData () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  4  0x0000002a963184cf in QStyledItemDelegate::qt_static_metacall () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  5  0x0000002a9699820e in QObject::event () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  6  0x0000002a95c75e00 in QApplicationPrivate::notify_helper () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  7  0x0000002a95c7e6ff in QApplication::notify () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  8  0x0000002a9697a13b in QCoreApplication::notifyInternal () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  9  0x0000002a9697c42d in QCoreApplicationPrivate::sendPostedEvents () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  10 0x0000002a969ae973 in ?? () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  11 0x000000315bc266bd in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
  12 0x000000315bc28397 in ?? () from /usr/lib64/libglib-2.0.so.0
  13 0x000000315bc288eb in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
  14 0x0000002a969af4f5 in QEventDispatcherGlib::processEvents () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  15 0x0000002a95d2e6f9 in QGuiEventDispatcherGlib::processEvents () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtGui.so.4
  16 0x0000002a96978f13 in QEventLoop::processEvents () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  17 0x0000002a969793c1 in QEventLoop::exec () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  18 0x0000002a9697c76f in QCoreApplication::exec () from /home/aminasya/checkout/ToT_test_072213/ic/ic_superproj/aof-dbg/Mgc_home//pkgs/icv_lib/lib64/libQtCore.so.4
  19 0x000000000423122e in nlb::application::runGuiMode (argc=1, argv=0x7fbfffe888, args=
        {mode = nlb::application::Application::MODE_GUI, databasePath = {static null = {&lt;No data fields&gt;}, static shared_null = {ref = {_q_value = 805}, alloc = 0, size = 0, data = 0x6b8d79a, clean
  = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, static shared_empty = {ref = {_q_value = 25}, alloc = 0, size = 0, data = 0x2a96bef7da, clean = 0, s
  impletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x2a96bef7c0, static codecForCStrings = 0x0}, scriptPath = {static null = {&lt;No data fields&gt;}, static s
  hared_null = {ref = {_q_value = 805}, alloc = 0, size = 0, data = 0x6b8d79a, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, static shared_emp
  ty = {ref = {_q_value = 25}, alloc = 0, size = 0, data = 0x2a96bef7da, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x6b8d780, static c
  odecForCStrings = 0x0}, scriptArgs = {static null = {&lt;No data fields&gt;}, static shared_null = {ref = {_q_value = 805}, alloc = 0, size = 0, data = 0x6b8d79a, clean = 0, simpletext = 0, righttoleft
  = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, static shared_empty = {ref = {_q_value = 25}, alloc = 0, size = 0, data = 0x2a96bef7da, clean = 0, simpletext = 0, righttoleft = 0, a
  sciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x6b8d780, static codecForCStrings = 0x0}, help = false}, initialArgumentParsingSuccessed=true) at Isrc/NLBMain.C:366
  </code></pre>