[texworks] Bug in 0.4.5 r.1280 (MikTeX 2.9): HOME set incorrectly

[Duncan Murdoch]

This bug seems to affect the MikTeX version, but not the "official" one.

When running a typesetting too, it constructs the HOME environment 
variable incorrectly.  For example, before starting TeXWorks I have no 
HOME set, just HOMEDRIVE and HOMEPATH.  (This is pretty standard in 
Windows 7; not sure about other versions).

When I start TeXWorks and create a fake typesetting tool that runs 
cmd.exe, I can type SET HOME in the console prompt, and I see this:

HOMEPATH=\Users\murdoch

HOME=C:\\Users\murdoch

HOMEDRIVE=C:


Notice the double backslash after C: in HOME.  That's not a valid path 
on Windows, so my real typesetting tool (R) fails when it can't find the 
user's home directory.