Re: [bug-diffutils] [PATCH] quoting in diff3 on win32

[Eric Blake]

On 08/25/2011 01:58 PM, Claudio Bley wrote:
> Hi.
>
> I compiled diffutils for MinGW.
>
> diff3.exe does not work with special characters in path names (like
> spaces et cetera) because it does not quote special characters
> correctly for the cmd shell when invoking diff.exe.

Gross.  It would be better to get the mingw environment to use sh 
instead of cmd, or to at least fix system() or popen() to properly munge 
command lines that assumed sh quoting into something that will work when 
passed to cmd, and to put that fix in mingw (or perhaps in  gnulib) for 
all projects to benefit from, than to hack up diffutils to support a 
non-standard, poorly documented, and painful alternate quoting mechanism 
just for a non-free shell.

> @@ -1217,6 +1267,9 @@
>     p = shell_quote_copy (p, filea);
>     *p++ = ' ';
>     p = shell_quote_copy (p, fileb);
> +#if defined(WIN32)&&  !defined(__CYGWIN__)
> +  *p++ = '"';
> +#endif
>     *p = 0;
>     errno = 0;
>     fpipe = popen (command, "r");

Or, instead of using popen, maybe we could use gnulib's pipe-filter-gi 
module, which allows us to pass the filename as a distinct argv argument 
without the need for any extra quoting to be undone by an intermediate 
shell.

All in all, while I appreciate your attempt to make this more robust on 
mingw, I think this patch is going about a solution in the wrong way.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org