--- gnus-spec.el.orig	Wed Feb 20 00:15:32 2002
+++ gnus-spec.el	Sat Oct 12 16:38:48 2002
@@ -396,6 +396,24 @@
 		     ,(when (not side) '(make-string need ?\ )))
 	   val)))))
 
+(defun gnus-simple-format (str &rest objects)
+  ;; A replacement for FORMAT which only handles %s and %% formats.
+  ;; Xemacs FORMAT does not preserve text properties on the input
+  ;; strings, whereas this version does. Without this function, returning
+  ;; strings with properties set from user-defined spec functions does not
+  ;; work in xemacs. Arguably, this function should just be an alias for
+  ;; format in FSF emacs (where properties are preserved), for speed if
+  ;; nothing else.
+  (with-temp-buffer
+    (insert str)
+    (goto-char (point-min))
+    (while (search-forward "%s" nil t)
+      (let ((obj (car objects)))
+	(replace-match (if (stringp obj) obj (format "%s" obj))
+		       nil t))
+      (setq objects (cdr objects)))
+    (gnus-replace-in-string (buffer-string) "%%" "%")))
+
 (defun gnus-parse-format (format spec-alist &optional insert)
   ;; This function parses the FORMAT string with the help of the
   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
@@ -642,6 +660,19 @@
       ;; A single string spec in the end of the spec.
       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
        (list (match-string 1 fstring) (car flist)))
+      ;; Nothing but %% and (bare) %s specs.
+      ;; We use a special replacement for format here to work around the
+      ;; fact that XEmacs FORMAT does not preserve text properties,
+      ;; without having to reimplement FORMAT in all its glory.
+      ;; The code above never uses format codes other than %% and %s for
+      ;; XEmacs in any case. (It uses %NNNs if gnus-use-correct-string-widths
+      ;; is not set, but we don't consider that here - it's a non-standard
+      ;; case and complicates the implementation of gnus-simple-format).
+      ;; Only do this for XEmacs, as we don't want FSF Emacs users to suffer
+      ;; an unnecessary performance hit.
+      ((and (featurep 'xemacs)
+            (string-match "\\`\\([^%]\\|%[s%]\\)*\\'" fstring)))
+       (list (cons 'gnus-simple-format (cons fstring (nreverse flist)))))
       ;; A more complex spec.
       (t
        (list (cons 'format (cons fstring (nreverse flist)))))))