Hello, Michael.

Just to be clear - we're talking about the current master. That one does 
not work. My original patch, or your rewrite in this thread works.

So here's what happens.

1. Msg-file has a local name as its value. Let's say I'm trying to 
commit into repository /pscp:server:/home/user/git-test/. 
Make-nearby-temp-file creates a file 
"/pscp:server:/home/user/git-test/git-msg23408zHn". Msg-file becomes 
"/home/user/git-test/git-msg23408zHn".

2. We concat a git command like "git commit 
/home/user/git-test/git-msg23408zHn". No problem here, since we need a 
local name.

3. (write-region (car args) nil msg-file) happens and it fails, because 
local name "/home/user/git-test/git-msg23408zHn" expands to 
"c:/home/user/git-test/git-msg23408Ncz" which is a file on a local 
machine and it does not exist.

The fix would be having absolute name for 
msg-file(/pscp:server:/home/user/git-test/git-msg23408zHn) and then 
using (or (file-remote-p msg-file 'localname)  msg-file) for git commit. 
Everywhere else we need the absolute name.

I've attached those changes as patch.

-- 
Best Regards,
Nikolay Kudryavtsev