Crash open file dialog start directory with unicode gtk 210

In recent gtk210 builds (especially 0611251018) Inkscape crashes when the
open file dialog is opened.

This crash only happens when the inkscape executable and libraries are in a
path that contains non-ascii characters, particularly Japanese characters.

This crash didn't happen with 2.8 builds.

This is a crash is fairly low impact, as typically inkscape will be started
in C:\Program Files\, but may indicate problems in gtk. If this is clearly
a lib issue we can report it to the gtk project, but I'm not sure where to
do that.

Here is the top of the backtrace

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? () from
(gdb) bt
#0 0x00000000 in ?? () from
#1 0x00416098 in inkscape_segv_handler (signum=22) at
src/inkscape.cpp:537
#2 0x77be52da in raise () from C:\WINDOWS\system32\msvcrt.dll
#3 0x00000016 in ?? ()
#4 0x082e6150 in ?? ()
#5 0x0022ec58 in ?? ()
#6 0x0022ecd8 in ?? ()
#7 0x664e1ec8 in ?? ()
   from c:\Documents and
Settings\James\デスクトップ\inkscape\libglibmm-2.4--
#8 0x6655a330 in ?? ()
   from c:\Documents and
Settings\James\デスクトップ\inkscape\libglibmm-2.4--
#9 0x6655c050 in ?? ()
#10 0x0022ec8c in ?? ()
#11 0x00415520 in inkscape_active_document () at src/xml/repr.h:146
#12 0x77be6bc1 in msvcrt!abort () from C:\WINDOWS\system32\msvcrt.dll
#13 0x00000016 in ?? ()
#14 0x0000000a in ?? ()
#15 0x664e8cd0 in ?? ()
   from c:\Documents and
Settings\James\デスクトップ\inkscape\libglibmm-2.4--
#16 0x082e6150 in ?? ()
#17 0x00000001 in ?? ()
#18 0x00000002 in ?? ()
#19 0x77c0fcc0 in msvcrt!_iob ()