Re: [PATCH 1/1] Avoid illegal filenames when building Documentation on NTFS

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Junio,

On Tue, 9 Jul 2019, Junio C Hamano wrote:

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>
> > In addition, your `+` scheme will break on Windows once it uses
> > `git.exe` or any other non-MSYS2 helper...
>
> I am not sure what you mean here.  Is your git.exe disabled not to
> be able to do this: "git.exe add hello+kitty.txt"?  I think that is
> a more grave problem, and not limited to the Makefile in the
> Documentation/ directory.

A `+` character is not allowed as part of a file name on Windows.
Therefore, it is not so much `git.exe`'s problem, as the Git build's
problem that it uses such an illegal character.

It _just happens_ to work at the moment, by virtue of Git for Windows'
SDK _by happenstance_ using only MSYS2-programs to manipulate those
files in question. And MSYS2 programs use a derivative of the Cygwin
runtime which uses a dirty trick to pretend _to MSYS2 programs only_
that `+` (and other characters that are equally illegal in file names on
Windows) can be used for file names: those characters are mapped into
a private page of the Unicode range.

Needless to say, only MSYS2 programs know how to deal with such file
names. If you ever use any program that is not based on the MSYS2/Cygwin
runtime (such as `git.exe`), things will break.

This strikes me as a fragile setup, hence my attempt to fix it.

Ciao,
Dscho