Re: [msysGit] [PATCH] mingw: work around stat-limitation
- From
Erik Faye-Lund <kusmabite@gmail.com>
- Date
- Feb 23, 2012, 21:36 UTC
- Message-ID
- <CABPQNSZ+=no5PKkaa8_44FbOzh_W4A5knoxKgDQ2wTvOaeKdew@mail.gmail.com>
- In-Reply-To
- <alpine.DEB.1.00.1202231525320.3340@s15462909.onlinehome-server.info>
On Thu, Feb 23, 2012 at 10:26 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
Show 16 quoted lines
> Hi, > > On Thu, 23 Feb 2012, Erik Faye-Lund wrote: > >> Our stat implementation for Windows always sets st_ino to 0. This >> means that checking if isatty(0) and comparing the reported inodes >> of stdout and stdin is not sufficient to detect that both are >> pointing to the same TTY. >> >> Luckily, there's only one console on Windows, so adding a check for >> isatty(1) should do the trick. For platforms where inodes are >> reported correctly, this should still be correct. > > Sorry to ask so stupidly, but why does isatty(1) work and isatty(0) does > not? Should they not access the very same console object? >
The point is that they might not. The old test would draw the wrong conclusion if isatty(0) was true, but isatty(1) was not because it used st_ino to verify that stdin and stdout pointed to the same terminal. The reason it did that was to catch cases where stdin and stdout pointed to different terminals, AFAICT. Not checking isatty(1) was simply an optimization, which works when st_ino is filled out correctly.
On Windows there is only one terminal, so it's sufficient to check if both are connected.