Comment 5 for bug 1670688

Patch from the attached branch tested successfully on Windows 7 (64-bit) with lp:inkscape 32 and 64-bit versions rev. 15590 (experimentally built with MSYS2).

No obvious regression found for now, but I'm not expert in that part of the code. So I would be nice if someone else could review it.

@Minglangjun Li - Thanks for working on it!