Re: vc-sccs.el sends bad args to cmp(1) via vcdiff script

[Kevin Rodgers <ihs_4664@yahoo.com>]

Jim Marks wrote:
 > This problem surfaces on Sun Solaris when trying to use
 > version control with SCCS as the backend.
 >
 > The source file gnu/share/emacs/21.4/lisp/vc-sccs.el has the following
 > defun:
 >
 > (defun vc-sccs-workfile-unchanged-p (file)
 >   "SCCS-specific implementation of vc-workfile-unchanged-p."
 >   (zerop (apply 'vc-do-command nil 1 "vcdiff" (vc-name file)
 >                 (list "--brief" "-q"
 >                       (concat "-r" (vc-workfile-version file))))))
 >
 > The important thing here is that the "--brief" option gets passed
 > to vcdiff as well as the "-r" option.
 >
 > On my system, vcdiff is a helper script in
 >
 > gnu/libexec/emacs/21.4/sparc-sun-solaris2.8/vcdiff
 >
 > It contains this code:
 >
 >
 >                 case $f in
 >                 --brief)
 >                         DIFF=cmp;;
 >
 > and, later, executes $DIFf.  This causes cmp to be invoked
 > with a "-r" option.  I can't find any Unix-clone on which
 > cmp(1) takes "-r".  This will always cause certain vc operations
 > to fail on systems where SCCS is the vc backend.

Are you sure?  I have 21.4 installed, and the vcdiff script also
processes the -rSID1 and -rSID2 options so that they are not passed to
cmp:

		-r?*)
			case $sid1 in
			'')
				sid1=$f
				;;
			*)
				case $sid2 in
				?*) echo "$usage" >&2; exit 2 ;;
				esac
				sid2=$f
				;;
			esac
			;;

Perhaps your problem is that vc-workfile-version is returning nil, which
would cause "-r" to be passed to vcdiff, which it cannot handle.

-- 
Kevin Rodgers