This topic branch addresses a problem identified in
https://github.com/git-for-windows/git/issues/439: while
cloning/fetching/pushing from "POSIX-ified UNC paths" (i.e. UNC paths
whose backslashes have been converted to forward slashes) works for some
time now, true UNC paths (with backslashes left intact) were handled
incorrectly. Example:
git clone //myserver/folder/repo.git
works, but
git clone \\myserver\folder\repo.git
(in CMD; in Git Bash, the backslashes would need to be doubled) used to
fail. The reason was an unexpected difference in command-line handling
between Win32 executables and MSYS2 ones (such as the shell that is used
by git-clone.exe to spawn git-upload-pack.exe).
This topic branch features a workaround *just* for the case where Git
passes stuff through sh.exe (which covers quite a few use cases,
though).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>