Re: [PATCH] Support DOS paths in dash

[Eric Blake <eblake@redhat.com>]

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[I noticed an old thread in my inbox while packaging dash 0.5.8 for Cygwin]

On 03/28/2013 09:08 AM, Edward Lam wrote [to the cygwin list]:

>> The problem is that dash tries to convert c:/windows to an absolute
>> path, since it doesn't start with /.  I suppose I could teach dash to
>> recognize [letter]:/ as absolute paths, although that makes dash larger,
>> and puts a burden on me (since I can guarantee upstream dash won't
>> accept such a patch).
>>
>>> I just don't care enough for DOS paths so I won't fix.
>>
>> Me neither.  And since you can use /cygdrive/c, not c:/, I won't bother
>> to fix it.
>>

> Hi Folks,
>
> I finally got down to looking at how to fix this in dash and came up
> with the attached patch (against dash-0.5.7). It's simple enough and so
> cd now works.
>
> Please consider this for Cygwin.
>

I'm not interested in burdening the cygwin build of dash with a one-off
patch, so I'd like to gauge the upstream thoughts - is it worth
including platform-specific patches like this (no penalty to build size
of non-cygwin platforms, and on cygwin, it allows 'cd c:/' to behave as
shorthand for 'cd /cygdrive/c/')?  If the patch lands in dash.git, then
I'll rebuild the cygwin port of dash to include a backport (rather than
waiting for 0.5.9 to be released).  If there is no interest, I'd rather
just drop the patch.  The cygwin community already states that
/cygdrive/c notation is the official way to access drive letters, and
that if 'c:/' works it is nice, but it is not a design goal to always
have it work.

> --- src/cd.c	2011-03-15 03:18:06.000000000 -0400
> +++ src/cd.new.c	2013-03-28 11:03:32.649576500 -0400
> @@ -38,6 +38,9 @@
>  #include <string.h>
>  #include <unistd.h>
>  #include <limits.h>
> +#ifdef __CYGWIN__
> +#include <sys/cygwin.h>
> +#endif
>  
>  /*
>   * The cd and pwd commands.
> @@ -194,6 +197,11 @@
>  	char *cdcomppath;
>  	const char *lim;
>  
> +#ifdef __CYGWIN__
> +        char pathbuf[PATH_MAX + 1];
> +        cygwin_conv_to_full_posix_path (dir, pathbuf);

By the way, cygwin_conv_to_full_posix_path() is deprecated (it suffers
from possible buffer overflow); these days, it's preferred to use:

cygwin_conv_path (CCP_WIN_A_TO_POSIX | CCP_RELATIVE, string, pathbuf,
                  sizeof(pathbuf))

So, if there is interest in this patch upstream, I can respin it.

> +	 dir = pathbuf;
> +#endif
>  	cdcomppath = sstrdup(dir);
>  	STARTSTACKSTR(new);
>  	if (*dir != '/') {
> 
> 


-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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