Date: Sun, 9 Apr 2006 21:34:15 -0400
From: Christopher Faylor <cgf-no-personal-reply-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Cygwin backwards compatibility break with WinMain and GetCommandLine (was Re: WinMain() not getting cl...)
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On Tue, Apr 04, 2006 at 11:44:47AM -0700, David Rothenberger wrote:
>WinMain() in a program compiled with cygwin1.dll is no longer
>getting passed the command-line from bash correctly with the
>20060403 snapshot. It works fine with the 20060329 snapshot.
>
>This is the same problem mentioned in
><http://cygwin.com/ml/cygwin/2005-09/msg00298.html>.
>
>The same test case is attached here again (winCmdLine.c). I compile
>it with "gcc -o winCmdLine winCmdLine.c" (note no -mno-cygwin).

This is due to recent changes which cause cygwin to stop filling out the
command-line for cygwin1.dll using programs.  We did this to fix the
"long command line" problem.

There is a crude workaround for the problem which reinstates the
previous cygwin behavior but I really would rather not go that way.  It
would be nice if, just this once, we could make cygwin a little faster
at the expense of programs which are using a non-linux-like interface.

So, I'm thinking that if you want your WinMain or GetCommandLine using
program to work with Cygwin 1.5.20 then you'll have to relink it.  I
realize that this is a major departure from previous stated goal of
maintaining backwards compatibility but we've already broken that once
in recent memory with the case of pure Windows environment variables so
I think we probably will just take the logical next step and break
things for WinMain and GetCommandLine as well.

If there are a lot of programs out there which are using WinMain or
GetCommandLine then I guess we'll hear about it.  Otherwise, unless
someone can convince me that this is a bad idea, Cygwin will start
carrying a GetCommandLine substitute which regenerates the command line
from the argv list.  I have something ready to go in my sandbox now
but I thought I'd hold off doing this in case someone had a valid
objection to this approach.

cgf

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