X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 	tests=AWL,BAYES_00,SPF_SOFTFAIL
X-Spam-Check-By: sourceware.org
Message-ID: <49EE9A96.6040900@byu.net>
Date: Tue, 21 Apr 2009 22:18:30 -0600
From: Eric Blake <ebb9 AT byu DOT net>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.21) Gecko/20090302 Thunderbird/2.0.0.21 Mnenhy/0.7.6.666
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: [1.7] Updated: cygwin-1.7.0-45
References: <20090402171059 DOT GE12738 AT calimero DOT vinschen DOT de> <20090331111757 DOT GA22043 AT calimero DOT vinschen DOT de> <200904031037 DOT n33Ab4Ma001073 AT mail DOT bln1 DOT bf DOT nsn-intra DOT net> <20090403145139 DOT GJ12738 AT calimero DOT vinschen DOT de> <200904211025 DOT n3LAPf7a022955 AT mail DOT bln1 DOT bf DOT nsn-intra DOT net> <20090421152334 DOT GH8722 AT calimero DOT vinschen DOT de> <20090421161337 DOT GG18867 AT trikaliotis DOT net> <20090421165642 DOT GK8722 AT calimero DOT vinschen DOT de> <20090421175436 DOT GA18266 AT calimero DOT vinschen DOT de> <49EE5D4D DOT 8030906 AT gmail DOT com>
In-Reply-To: <49EE5D4D.8030906@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-IsSubscribed: yes
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

According to Dave Korn on 4/21/2009 5:57 PM:
>> And better so since sed isn't broken.  It puts EOF into the isblank
>> function and rightly expects that isblank returns 0.
> 
>   I thought the problem was that it puts 0xff into the isblank function and
> gets 1 in some locales where 0xff is an NBSP, if that's not the case I've
> misunderstood the thread so far.

The bug was that isblank(-1) was blindly treated as if were equivalent
with isblank(0xff), which, in some locales, is flat out wrong
(isblank(EOF) should always be 0, even when isblank(0xff) is well-defined
as 1).  Broken apps can't tell the difference between isblank((char)0xff)
and isblank(EOF), but correct apps, like sed, CAN tell the difference
between 0xff and EOF in "int ch = getchar(); isblank(ch)" since getchar()
returns an int containing an unsigned char value (and not a char).

Sed's infinite loop, then, was because of newlib/cygwin's bug - sed
reached the end of the file while trying to skip blanks, but because
isblank() was returning the wrong value for -1, sed thought that EOF was a
blank and kept trying to read the file instead of breaking out of the loop.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             ebb9 AT byu DOT net
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAknumpYACgkQ84KuGfSFAYDOfgCeLGrunriMXtbakIUc+8zZQ8TA
+tgAnjidi630v2rf4q79zWv2MCJ3CBWC
=f2gG
-----END PGP SIGNATURE-----

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/