X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-3.2 required=5.0	tests=AWL,BAYES_00,KHOP_THREADED,RCVD_IN_DNSWL_NONE,RCVD_IN_HOSTKARMA_YE,SPF_HELO_PASS
X-Spam-Check-By: sourceware.org
Message-ID: <4FB5360B.50902@towo.net>
Date: Thu, 17 May 2012 19:31:55 +0200
From: Thomas Wolff <towo AT towo DOT net>
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: [PATCH] fix broken mouse in Cygwin 1.7.14 and 1.7.15
References: <alpine DOT DEB DOT 2 DOT 00 DOT 1205170048200 DOT 17561 AT artax DOT karlin DOT mff DOT cuni DOT cz> <alpine DOT DEB DOT 2 DOT 00 DOT 1205170119430 DOT 21332 AT artax DOT karlin DOT mff DOT cuni DOT cz> <20120517021910 DOT GB10314 AT ednor DOT casa DOT cgf DOT cx>
In-Reply-To: <20120517021910.GB10314@ednor.casa.cgf.cx>
X-TagToolbar-Keys: D20120517193154798
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
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

Am 17.05.2012 04:19, schrieb Christopher Faylor:
> On Thu, May 17, 2012 at 01:20:06AM +0200, Mikulas Patocka wrote:
>> On Thu, 17 May 2012, Mikulas Patocka wrote:
>>
>>>> Corinna Vinschen:
>>>>
>>>>> 2012-04-03  Thomas Wolff
>>>>>
>>>>> 	* fhandler.h (class dev_console): Two flags for extended mouse modes.
>>>>> 	* fhandler_console.cc (fhandler_console::read): Implemented
>>>>> 	extended mouse modes 1015 (urxvt, mintty, xterm) and 1006 (xterm).
>>>>> 	Not implemented extended mouse mode 1005 (xterm, mintty).
>>>>> 	Supporting mouse coordinates greater than 222 (each axis).
>>>>> 	Also: two { wrap formatting consistency fixes.
>>>>> 	(fhandler_console::char_command) Initialization of enhanced
>>>>> 	mouse reporting modes.
>>>>
>>>> Patch applied with changes.  Please use __small_sprintf rather than
>>>> sprintf.  I also changed the CHangeLog entry slightly.  Keep it short
>>>> and in present tense.
>>> Hi
>>>
>>> The change (sprintf ->  __small_sprintf) that Corinna applied actually
>>> broke mouse reporting. It is broken in Cygwin 1.7.14 and 1.7.15.
>>>
>>> When the user clicks with the first button, the mouse down event is
>>> reported incorrectly, the mouse down event always looks like this:
>>>   1b 5b([) 4d(M) 30(0) 78(x) 32(2)
>>> Note that there is 0x30 (instead of 0x20) as the button. And there are
>>> always fixed coordinates (0x78, 0x32), regardless of where the user
>>> clicks.
>>>
>>> This bug breaks the Links textmode browser (if you click on the top line,
>>> you should see the menu, but you don't with Cygwin 1.7.14 and 1.7.15). It
>>> also break Midnight Commander (if you start it with "TERM=xterm mc") and
>>> all other programs that use xterm-style mouse reporting.
>>>
>>> The reason is that __small_sprintf and sprintf aren't equivalent.
>>> __small_sprintf processes '%c' format string differently from sprintf. A
>>> piece of code from smallprint.cc:
>>>
>>> case 'c':
>>>    {
>>>      int c = va_arg (ap, int);
>>>      if (c>  ' '&&  c<= 127)
>>>        *dst++ = c;
>>>      else
>>>        {
>>>          *dst++ = '0';
>>>          *dst++ = 'x';
>>>          dst = __rn (dst, 16, 0, c, len, pad, LMASK);
>>>        }
>>>    }
>>>    break;
>>>
>>> We see that if the character is outside the range 0x21..0x7f,
>>> __small_sprintf prints 0x and the hex value. On the other hand, sprintf
>>> copies the byte unchanged.
>>>
>>> __small_sprintf("%c", 32) doesn't print space, it prints 0x20 --- and this
>>> breaks mouse click reporting. It also breaks the extended coordinate
>>> reporting implemented by Thomas because it need to print characters>=
>>> 0x80.
>>>
>>> The attached patch fixes the mouse bug by changing __small_sprintf back to
>>> sprintf. Alternatively, you can fix __small_sprintf to process "%c"
>>> consistently with sprintf, but I don't know how much other code is
>>> dependent on the current peculiar "%c" processing. So it's safer to change
>>> mouse reporting calls to use sprintf.
> I don't know where that odd code came from.  It's apparently been in
> smallprint.{c,cc} forever.  I'm nuking it.  I see one potential problem
> in fhandler_socket::bind.  It won't be hard to work around if that
> function was really relying on it.
>
> Thanks for tracking this down.  The change will be in the next snapshot.
And thanks for analyzing this show-stopper for my mouse reporting patch; 
I should have noticed myself...
Thomas

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