--- grep.el.orig	2006-08-22 18:24:34.734375000 +0100
+++ grep.el	2006-08-22 19:55:58.703125000 +0100
@@ -335,10 +335,18 @@
 (defvar grep-find-use-xargs nil
   "Whether \\[grep-find] uses the `xargs' utility by default.
 
-If nil, it uses `find -exec'; if `gnu', it uses `find -print0' and `xargs -0';
-if not nil and not `gnu', it uses `find -print' and `xargs'.
+If `no', it uses `find -exec'; if `gnu', it uses `find -print0'
+and `xargs -0'; if `yes', it uses `find -print' and `xargs'.
 
-This variable's value takes effect when `grep-compute-defaults' is called.")
+This variable's value takes effect when `grep-compute-defaults'
+is called.
+
+\(For backwards compatibility, if `grep-find-use-xargs' is nil,
+`grep-compute-defaults' will set it to one of `gnu' or `no'; or,
+if `grep-find-use-xargs' is non-nil, but not one of the valid
+settings, `grep-compute-defaults' will set it to `yes'.\)
+
+")
 
 ;; History of grep commands.
 ;;;###autoload
@@ -382,6 +390,7 @@
 	   (error nil))
 	 (or result 0)))
 
+
 ;;;###autoload
 (defun grep-compute-defaults ()
   (unless (or (not grep-use-null-device) (eq grep-use-null-device t))
@@ -417,23 +426,39 @@
       (unless grep-template
 	(setq grep-template
 	      (format "%s <C> %s <R> <F>" grep-program grep-options)))
-      (unless grep-find-use-xargs
-	(setq grep-find-use-xargs
-	      (if (and
-		   (grep-probe find-program `(nil nil nil ,null-device "-print0"))
-		   (grep-probe "xargs" `(nil nil nil "-0" "-e" "echo")))
-		  'gnu)))
+      ;; "Normalize" `grep-find-use-xargs'. Hardly ideal, but
+      ;; preserves the previous behaviour (unless 'no was being as the
+      ;; non-null value of course).
+      ;; 
+      ;; Presumably keeping nil to mean 'auto-detect' is desirable?
+      (setq grep-find-use-xargs
+	    (cond ((null grep-find-use-xargs)
+		   (if (and
+			 (grep-probe find-program `(nil nil nil ,null-device "-print0"))
+			 (grep-probe "xargs" `(nil nil nil "-0" "-e" "echo")))
+			'gnu
+		      'no))
+		  ((not (or (eq grep-find-use-xargs 'gnu)
+			    (eq grep-find-use-xargs 'no)))
+		   'yes)
+		  (t
+		   'no)))
       (unless grep-find-command
 	(setq grep-find-command
 	      (cond ((eq grep-find-use-xargs 'gnu)
 		     (format "%s . -type f -print0 | xargs -0 -e %s"
 			     find-program grep-command))
-		    (grep-find-use-xargs
+		    ((eq grep-find-use-xargs 'yes)
 		     (format "%s . -type f -print | xargs %s"
 			     find-program grep-command))
-		    (t (cons (format "%s . -type f -exec %s {} %s \\;"
-				     find-program grep-command null-device)
-			     (+ 22 (length grep-command)))))))
+		    ((eq grep-find-use-xargs 'no)
+		     (let ((command (format "%s . -type f -exec %s {} %s %s"
+				      find-program grep-command null-device (shell-quote-argument ";"))))
+		       (cons command
+			     (+ (string-match (regexp-quote grep-command)
+					       command)
+				(length grep-command)
+				1)))))))
       (unless grep-find-template
 	(setq grep-find-template
 	      (let ((gcmd (format "%s <C> %s <R>"
@@ -441,11 +466,12 @@
 		(cond ((eq grep-find-use-xargs 'gnu)
 		       (format "%s . <X> -type f <F> -print0 | xargs -0 -e %s"
 			       find-program gcmd))
-		      (grep-find-use-xargs
+		      ((eq grep-find-use-xargs 'yes)
 		       (format "%s . <X> -type f <F> -print | xargs %s"
 			       find-program gcmd))
-		      (t (format "%s . <X> -type f <F> -exec %s {} %s \\;"
-				 find-program gcmd null-device))))))))
+		      ((eq grep-find-use-xargs 'no)
+		       (format "%s . <X> -type f <F> -exec %s {} %s %s"
+			       find-program gcmd null-device (shell-quote-argument ";")))))))))
   (unless (or (not grep-highlight-matches) (eq grep-highlight-matches t))
     (setq grep-highlight-matches
 	  (with-temp-buffer
@@ -736,18 +762,23 @@
       (let ((command (grep-expand-template
 		      grep-find-template
 		      regexp
-		      (concat "\\( -name "
+		      (concat (shell-quote-argument "(")
+			      " -name "
 			      (mapconcat #'shell-quote-argument
 					 (split-string files)
 					 " -o -name ")
-			      " \\)")
+			      " "
+			      (shell-quote-argument ")"))
 		       dir
 		       (and grep-find-ignored-directories
-			    (concat "\\( -path '*/"
+			    (concat (shell-quote-argument "(")
+				    " -path '*/"
 				    (mapconcat #'identity
 					       grep-find-ignored-directories
 					       "' -o -path '*/")
-				    "' \\) -prune -o ")))))
+				    "' "
+				    (shell-quote-argument ")")
+				    " -prune -o ")))));
 	(when command
 	  (if current-prefix-arg
 	      (setq command