A user was in #mercurial and had the following settings in their hgrc:
[ui] editor = C:\home\npp\notepad++.exe -multiInst -nosession
After shlexsplit, the first argument was mangled into C:homenppnotepad++.exe,
which was quite unlikely to exist. It took many back-and-forths to identify
that adding " characters around the exe would fix the issue; we were thinking
that it's because something was incorrectly *not* splitting and adding/moving
the " characters fixed the split boundaries, but when testing afterward it
appears that it's just mangled.
I considered adding an informational if pycompat.iswindows and \ in the string
about this issue, but was worried that might have too many false positives and
did not do so at this time.
In this patch, we end up printing something potentially different in the "checking" line than in the "can't find editor" line. That seems wrong. I think I'd rather we do the shlexsplit before writing the "checking commit editor..." message and print the fully-interpreted path there.