Enhance XEmacs compatibility

* lisp/org-list.el (org-list-search-unenclosed-generic): Replace call
to booleanp.

* lisp/org-compat.el (org-decompose-region): New defsubst.
* lisp/org.el (org-toggle-pretty-entities):
(org-unfontify-region): Use `org-decompose-region'.

lisp/org-compat.el

@@ -162,6 +162,15 @@ If DELETE is non-nil, delete all those overlays."
       (let ((x (org-get-x-clipboard-compat value)))
 	(if x (org-no-properties x)))))
 
+(defsubst org-decompose-region (beg end)
+  "Decompose from BEG to END."
+  (if (featurep 'xemacs)
+      (let ((modified-p (buffer-modified-p))
+	    (buffer-read-only nil))
+	(remove-text-properties beg end '(composition nil))
+	(set-buffer-modified-p modified-p))
+    (decompose-region beg end)))
+
 ;; Miscellaneous functions
 
 (defun org-add-hook (hook function &optional append local)

lisp/org-list.el

@@ -343,7 +343,7 @@ Arguments SEARCH, RE, BOUND and NOERR are similar to those in
       (while t
 	;; 1. No match: return to origin or bound, depending on NOERR.
 	(unless (funcall search re bound noerr)
-	  (throw 'exit (and (goto-char (if (booleanp noerr) origin bound))
+	  (throw 'exit (and (goto-char (if (memq noerr '(t nil)) origin bound))
 			    nil)))
 	;; 2. Match not in block or protected: return point. Else
 	;; skip the block and carry on.

lisp/org.el

@@ -5543,7 +5543,7 @@ needs to be inserted at a specific position in the font-lock sequence.")
       (message "Entities are displayed as UTF8 characers")
     (save-restriction
       (widen)
-      (decompose-region (point-min) (point-max))
+      (org-decompose-region (point-min) (point-max))
       (message "Entities are displayed plain"))))
 
 (defun org-fontify-entities (limit)
@@ -5643,7 +5643,7 @@ If KWD is a number, get the corresponding match group."
 	 (inhibit-read-only t) (inhibit-point-motion-hooks t)
 	 (inhibit-modification-hooks t)
 	 deactivate-mark buffer-file-name buffer-file-truename)
-    (decompose-region beg end)
+    (org-decompose-region beg end)
     (remove-text-properties
      beg end
      (if org-indent-mode