A toolbox separated and in wide shape, without the 3 toolbox area
({color/foo/image}_area as given in gimp_toolbox) as like this:
http://popolon.free.fr/scrinshot.jpg

in sessionrc, about toolbox:
(session-info "toolbox" "dock"
    (position 345 26)
    (size 928 66)
    (open-on-exit)
    (dock))

crash if the application started like this and gimpfgbgeditor is selected first
in preferences->toolbox.

Here the states of vars given in the crashing gimp_fg_bg_editor_expose function
(in app/widgets/gimpfgbgeditor.c):

at the starting of gimp:
width:269 height:48
default_w:12 default_h:12
swap_w:12 swap_h:12
rect_w:253 rect_h:34

just after clicking in the prefs checkbox and before crash:
width:54 height:1
default_w:12 default_h:12
swap_w:12 swap_h:12
rect_w:38 rect_h:-13

I don't find for why the toolbox as got this values by widget arg as:
width = widget->allocation.width;
height = widget->allocation.height;

There is a warning before the crash:
(gimp:21469): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate
widget with width 54 and height -5

And near the far warnin, if first trying to add foo_area
(pattern+brush+gradient) or image_area, width varying to 52 or 54 depending of
the area.

(gimp:21469): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate
widget with width 52 and height -5


To avoid a crash, activate on of the 2 other area first. If the fgbgcolor widget
is activated after one of the 3 other have been desactivated in same session,
there is no crash and the values given to function are:
width:54 height:42
default_w:12 default_h:12
swap_w:12 swap_h:12
rect_w:38 rect_h:28





When crash occur:
(gimp:25500): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate
widget with width 54 and height -5

GLib-ERROR **: gmem.c:141: failed to allocate 4294965736 bytes
aborting...
the value is negative and then seem to be converted directly to an unsigned long
integer??? (even if 4294967026 = -5*54 = -270 doesn't match...)

The gdb backtrace:
(gdb) bt

+ Trace 53972