Comment 37 for bug 176750

Don't know if this is the patch you mean, but the spawn patch should be in trunk, and ready to be applied in the \packaging\win32\patches folder for branch.
The patch I mean is here - https://bugs.launchpad.net/inkscape/0.46.x/+bug/204779 - although Adib did some mods from that which I didn't fully understand, but they seemed to do the same thing as the spawn patch on the bug.