From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jonathan Nieder <jrnieder@gmail.com>
Subject: Re: [PATCH] Makefile: don't run rm without any files
Date: Wed, 13 Feb 2013 12:12:44 -0800
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Cc: Matt Kraai <kraai@ftbfs.org>, git@vger.kernel.org,
	Matt Kraai <matt.kraai@amo.abbott.com>
To: Junio C Hamano <gitster@pobox.com>
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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 compile=
r
>     does not support it, $(dep_dirs) becomes empty.  "make clean" run=
s
>     "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 ar=
e
	no operands (useful for constructs like rm -rf $filelist without first
	checking if =E2=80=98$filelist=E2=80=99 was empty). But this was not a=
lways portable; at
	least NetBSD rm built before 2008 would fail with a diagnostic.

Anyway, looks like a good fix.  Thanks.