Re: [PATCH] Cygwin: utils: chattr: Improve option parsing.

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On May 20 21:48, Christian Franke wrote:
> Hi Corinna,
> 
> Corinna Vinschen wrote:
> > Hi Christian,
> > 
> > On May 20 12:01, Christian Franke wrote:
> > > Corinna Vinschen wrote:
> > > > On May 19 17:46, Christian Franke wrote:
> > > > > ...
> > > > > $ egrep 'ACL|--r' chattr.c
> > > > >             "Get POSIX ACL information\n"
> > > > >         "  -R, --recursive     recursively list attributes of directories and
> > > > > their \n"
> > > > Oops.  Please patch while you're at it...
> > > > ...
> > > > >   From 865a5a50501f3fd0cf5ed28500d3e6e45a6456de Mon Sep 17 00:00:00 2001
> > > > > From: Christian Franke<...>
> > > > > Date: Wed, 19 May 2021 16:24:47 +0200
> > > > > Subject: [PATCH] Cygwin: utils: chattr: Improve option parsing.
> > > > > 
> > > > > Interpret '-h' as '--help' only if last argument.
> > > > Who was the idiot using -h for help *and* the hidden flag? *blush*
> > > > 
> > > > I'd vote for --help to be changed to -H for the single character
> > > > option.  The help output is very unlikely to be used in scripts,
> > > > so that shouldn't be a backward compat problem.
> > > New patch attached.
> > > 
> > > Note that there is now the possibly unexpected (& hidden) behavior that
> > > 'chattr -h' without file argument clears the hidden attribute of cwd.
> > Uhm... why?
> 
> Because chattr uses '.' as default if no FILE argument is specified. The
> same applies to all other '+-=MODE' arguments. The patch does not change
> this behavior but of course enables it for '-h'.

Oh, right.  I can't reproduce this behaviour with the most recent chattr
from e2fsprogs in F33.  Sorry, I'm not sure anymore why I did that.  But
given the entire behaviour is rather unexpected, and it's not even
documented, maybe we should drop it, too?  Not sure if backward compat
counts in this case...

> Another behavior (possibly inherited from lsattr) is also not very useful:
> 'chattr +-=MODE DIRECTORY' also changes the attributes of all elements in
> the directory (not recursively). It is not possible to solely change the
> attributes of a directory except if it is the current directory and no FILE
> argument is passed. Fixing this would again break backward compatibility.

Ouch, no!  That's a bug.  The expression in line 354 should have been

    if (S_ISDIR (st.st_mode) && Ropt && chattr_dir (argv[optind]))
		ret = 1;

the Ropt check is just missing.


Corinna