trunk: random crashes in Inkscape::Util::Unit::Unit () (Rows and Columns dialog)

[su_v]

Steps to reproduce:
1) launch inkscape (default prefs, default new doc)
2) open 'Rows and Columns' dialog with mnemonics 'Alt+O, W'
3) quickly click once on one of the up/down arrows of the spinbuttons for Row/Column

--> crash:

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: 13 at address: 0x0000000000000000
0x000000010038cde4 in Inkscape::Util::Unit::Unit (this=0x7fff5fbfe580, unnamed_arg=@0x7a4d10eff94020c5) at units.h:36
36 class Unit {

Reproduced with r12577 on OS X 10.7.5 with 4 different builds using completely separate build environments (versions of library dependencies vary):
- GTK+/X11 2.24.13, gtkmm 2.24.2, Glib 2.32.4, glibmm 2.32.1, libsigc++ 2.2.10
- GTK+/Quartz 2.24.17, gtkmm 2.24.2, Glib 2.34.3, glibmm 2.34.1, libsigc++ 2.2.10
- GTK+/X11 2.24.21, gtkmm 2.24.4, Glib 2.36.4, glibmm 2.36.2, libsigc++ 2.2.11
- GTK+/Quartz 2.24.21, gtkmm 2.24.4, Glib 2.36.4, glibmm 2.36.2, libsigc++ 2.2.11

Full backtrace from top-listed build (GTK+/X11 2.24.13) attached.

Note: it does not make a difference where there is a number of objects selected to be arranged in rows & columns or not. The crash occurs not consistently (possibly a timing issue?).

[jazzynico (jazzynico)]

Reproduced on Windows XP, Inkscape trunk revision 12577:

Program received signal SIGSEGV, Segmentation fault.
0x00d04588 in Inkscape::UI::Widget::UnitTracker::getActiveUnit ()

[Johan Engelen (johanengelen)]

there was a missing initialization bug, fixed in rev12581. probably this bug is fixed now too.

[su_v (suv-lp)]

I haven't been able to reproduce it with r12581 - let's close it. Thx for the fix!