Re: Is gtkmm deleting stuff it shouldn't be deleting ??

[John Emmas <johne53 tiscali co uk>]

Thanks for the suggestions, Murray.

On 04/11/2013 08:20, Murray Cumming wrote:
> This is with the gtkmm that you have built yourself, right, and from
> git, not from a tarball?
Up until yesterday, yes.  But yesterday I built gdkmm and gtkmm from the 
2.4.4 tarball and got the same results.  Over the next day or two I'll 
probably swap all my "mm" libraries to their tarball code and see if 
that changes anything.


> Do you have a backtrace?
Not at the moment.  MSVC isn't as good at generating backtraces as gcc 
is, although I should be able to get something...


> > If you are the only one who can reproduce this then I'm afraid you will
> > need to do some investigtion yourself. If this was happening for other
> > people they would notice rather quickly.
> >
> > At the very least, you might derive a Gtk::Window and put some std::cout
> > output in its destructor, to see when that is being called.

That's okay, I don't mind doing the detective work.  The crash has all 
the hallmarks of something getting "double deleted" but when I placed a 
breakpoint in Gtk::Window::~Window() there was no evidence that it was 
getting called twice.  Perhaps one of its components might be getting 
double deleted?  The only other thing which strikes me as odd is this:-

        // From gtk/gtkmm/window.cc...
        Window::~Window()
        {
            destroy_(); // <--- Breakpoint #2 here
        }

        // From my testing code (not the full example)...
        int main (int argc, char *argv[])
        {
            Gtk::Window* pW = new Gtk::Window;
            delete pW; // <--- Breakpoint #1 here

            return 0;
        }

When my code stops at breakpoint #1 I make a note of the value of 'pW'.  
When it stops at breakpoint #2 I'd expect my 'this' pointer to have the 
same value - but it doesn't.  It's always slightly different.  For 
example, when pW == 0x03604fb0 at breakpoint #1, I notice that at 
breakpoint #2, 'this' == 0x03604fcc.  I'm not familiar enough with gtkmm 
to know if that indicates a problem but there's a consistent difference 
between them.  Does that seem sensible to you?

John