From: Jonathan Nieder <jrnieder@gmail.com>
Date: Wed, 13 Feb 2013 20:12:44 GMT
Subject: Re: [PATCH] Makefile: don't run rm without any files
Message-ID: <20130213201244.GD3381@google.com>
In-Reply-To: <7vehgk6l11.fsf@alter.siamese.dyndns.org>

Junio C Hamano wrote:

> I amended the log message like so:
>
> commit bd9df384b16077337fffe9836c9255976b0e7b91
> Author: Matt Kraai <matt.kraai@amo.abbott.com>
> Date:   Wed Feb 13 07:57:48 2013 -0800
>
>     Makefile: don't run rm without any files
>
>     When COMPUTE_HEADER_DEPENDENCIES is set to "auto" and the compiler
>     does not support it, $(dep_dirs) becomes empty.  "make clean" runs
>     "rm -rf $(dep_dirs)", which fails in such a case.

To pedantic, that only fails on some platforms.  The autoconf manual
explains:

	It is not portable to invoke rm without options or operands. On the
	other hand, Posix now requires rm -f to silently succeed when there are
	no operands (useful for constructs like rm -rf $filelist without first
	checking if ‘$filelist’ was empty). But this was not always portable; at
	least NetBSD rm built before 2008 would fail with a diagnostic.

Anyway, looks like a good fix.  Thanks.