0002134: FreeCAD crashes when the window is restored and a plot is shown - FreeCAD Tracker

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ID	Project	Category	View Status	Date Submitted	Last Update

0002134	FreeCAD	Bug	public	2015-05-31 13:13	2015-12-15 13:18

Reporter	Sanguinario_Joe	Assigned To	wmayer
Priority	high	Severity	crash	Reproducibility	always
Status	closed	Resolution	fixed
Platform	64-bit	OS	Linux/Kubuntu	OS Version	14.04.2 LTS
Product Version	0.15
Fixed in Version	0.16

Summary	0002134: FreeCAD crashes when the window is restored and a plot is shown
Description	Plot module is causing a program crash when the Program is minimized and restored back later.
Steps To Reproduce	In the Python script view: import Plot Plot.plot([0,1], [0,1]) Minimize the window, and restore it back
Additional Information	GDB returns the following backtrace: Program received signal SIGSEGV, Segmentation fault. 0x00007ffff5584a4d in QWidget::windowTitle() const () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 (gdb) backtrace #0 0x00007ffff5584a4d in QWidget::windowTitle() const () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 #1 0x00007ffff73ba2ac in Gui::Application::viewActivated (this=0x7fffffffc9e0, pcView=0x0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:897 0000002 0x00007ffff76a90ee in Gui::MainWindow::changeEvent (this=0x7fffffffc800, e=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/MainWindow.cpp:1468 0000003 0x00007ffff5590cd0 in QWidget::event(QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000004 0x00007ffff594b9b3 in QMainWindow::event(QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000005 0x00007ffff76a2529 in Gui::MainWindow::event (this=0x7fffffffc800, e=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/MainWindow.cpp:623 0000006 0x00007ffff5541e2c in QApplicationPrivate::notify_helper(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000007 0x00007ffff55484a0 in QApplication::notify(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000008 0x00007ffff73c4297 in Gui::GUIApplication::notify (this=0x7fffffffc830, receiver=0x7fffffffc800, event=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:1547 0000009 0x00007ffff4dcb4dd in QCoreApplication::notifyInternal(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000010 0x00007ffff5546b44 in QApplication::setActiveWindow(QWidget) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000011 0x00007ffff55bbbe1 in QApplication::x11ProcessEvent(_XEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000012 0x00007ffff55e3b02 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000013 0x00007fffee279e04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000014 0x00007fffee27a048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000015 0x00007fffee27a0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000016 0x00007ffff4df87a1 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000017 0x00007ffff55e3bb6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000018 0x00007ffff4dca0af in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000019 0x00007ffff4dca3a5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000020 0x00007ffff4dcfb79 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000021 0x00007ffff73bf9c9 in Gui::Application::runApplication () at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:1822 0000022 0x0000000000408508 in main (argc=1, argv=0x7fffffffd1c8) at /home/pepe/FreeCAD/freecad.cmake/src/Main/MainGui.cpp:328
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FreeCAD Information

Sanguinario_Joe 2015-05-31 13:14 developer ~0006170	OS: Ubuntu 14.04.2 LTS Word size of OS: 64-bit Word size of FreeCAD: 64-bit Version: 0.16.5036 (Git) Build type: Debug Branch: sanguinariojoe-ship Hash: a12f700aa27792f0ecdf09c5ee190d0bf88b0e81 Python version: 2.7.6 Qt version: 4.8.6 Coin version: 4.0.0a

Sanguinario_Joe 2015-05-31 13:49 developer ~0006171	The problem comes from the line src/Gui/MainWindow.cpp:1463 MDIView* view =dynamic_cast<MDIView*>(mdi->widget()); While mdi->widget() has an actual memory address, view is nil, which of course will cause that Application::Instance->viewActivated(view) fail getting the window title.

Sanguinario_Joe 2015-05-31 14:40 developer ~0006172	Replacing the line by just a variable reinterpretation: MDIView* view = (MDIView)(mdi->widget()); It seems to pass OK through the problem, however it is exploding later anyway: Program received signal SIGSEGV, Segmentation fault. 0x00007ffff73e3fc3 in Gui::Document::getDocument (this=0x25802b0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Document.cpp:575 575 return d->_pcDocument; (gdb) backtrace #0 0x00007ffff73e3fc3 in Gui::Document::getDocument (this=0x25802b0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Document.cpp:575 #1 0x00007ffff73b9a08 in Gui::Application::setActiveDocument (this=0x7fffffffc9e0, pcDocument=0x25802b0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:772 0000002 0x00007ffff73ba389 in Gui::Application::viewActivated (this=0x7fffffffc9e0, pcView=0x25d7cc0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:910 0000003 0x00007ffff76a916b in Gui::MainWindow::changeEvent (this=0x7fffffffc800, e=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/MainWindow.cpp:1472 0000004 0x00007ffff5590cd0 in QWidget::event(QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000005 0x00007ffff594b9b3 in QMainWindow::event(QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000006 0x00007ffff76a257d in Gui::MainWindow::event (this=0x7fffffffc800, e=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/MainWindow.cpp:623 0000007 0x00007ffff5541e2c in QApplicationPrivate::notify_helper(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000008 0x00007ffff55484a0 in QApplication::notify(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000009 0x00007ffff73c42eb in Gui::GUIApplication::notify (this=0x7fffffffc830, receiver=0x7fffffffc800, event=0x7fffffffbde0) at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:1552 0000010 0x00007ffff4dcb4dd in QCoreApplication::notifyInternal(QObject, QEvent) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000011 0x00007ffff5546b44 in QApplication::setActiveWindow(QWidget) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000012 0x00007ffff55bbbe1 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000013 0x00007ffff55e3b02 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000014 0x00007fffee279e04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000015 0x00007fffee27a048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000016 0x00007fffee27a0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 0000017 0x00007ffff4df87a1 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000018 0x00007ffff55e3bb6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 0000019 0x00007ffff4dca0af in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000020 0x00007ffff4dca3a5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000021 0x00007ffff4dcfb79 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 0000022 0x00007ffff73bfa1d in Gui::Application::runApplication () at /home/pepe/FreeCAD/freecad.cmake/src/Gui/Application.cpp:1827 0000023 0x0000000000408508 in main (argc=1, argv=0x7fffffffd1c8) at /home/pepe/FreeCAD/freecad.cmake/src/Main/MainGui.cpp:328 GDB say that d points to an invalid address. I'm trying to figure out what's going on

wmayer 2015-05-31 15:21 administrator ~0006174	> MDIView* view =dynamic_cast<MDIView>(mdi->widget()); Hmm, this happens when adding any other widget to the QMdiArea. However, it is correct to use the C++ dynamic_cast as this correctly returns a null pointer if the widget of the QMdiSubWindow doesn't inherit from MDIView. > MDIView view = (MDIView*)(mdi->widget()); That's definitely worse because it gives you a dangling pointer that causes undefined behaviour.

Date Modified	Username	Field	Change
2015-05-31 13:13	Sanguinario_Joe	New Issue
2015-05-31 13:14	Sanguinario_Joe	Note Added: 0006170
2015-05-31 13:49	Sanguinario_Joe	Note Added: 0006171
2015-05-31 14:40	Sanguinario_Joe	Note Added: 0006172
2015-05-31 15:21	wmayer	Note Added: 0006174
2015-05-31 15:30	wmayer	Changeset attached	=> FreeCAD Master master 2e14552a
2015-05-31 15:30	wmayer	Assigned To	=> wmayer
2015-05-31 15:30	wmayer	Status	new => closed
2015-05-31 15:30	wmayer	Resolution	open => fixed
2015-12-15 13:18	yorik	Fixed in Version	=> 0.16