Subject: Re: bug#13942: 24.3.50; `smie-auto-fill' loops

From: Stefan Monnier <[email-masked]>
Date: Wed, 13 Mar 2013 23:05:24 -0400

> 3. Load the Coq test file, and trigger auto-filling by placing the
> cursor just after a to-long comment line and hitting ENTER. -> Emacs
> loops.

Aha!  The trick was to hit enter *after* the end of the comment!

I think the patch below fixes this problem, while still providing the
same auto-fill feature.  Can you confirm it works well for you?

        Stefan

=== modified file 'lisp/emacs-lisp/smie.el'
--- lisp/emacs-lisp/smie.el	2013-01-01 09:11:05 +0000
+++ lisp/emacs-lisp/smie.el	2013-03-14 00:49:52 +0000
@@ -1631,21 +1631,23 @@
 (defun smie-auto-fill ()
   (let ((fc (current-fill-column)))
     (while (and fc (> (current-column) fc))
-      (cond
-       ((not (or (nth 8 (save-excursion
+      (or (unless (or (nth 8 (save-excursion
                           (syntax-ppss (line-beginning-position))))
-                 (nth 8 (syntax-ppss))))
+                      (nth 8 (syntax-ppss)))
         (save-excursion
-          (beginning-of-line)
+              (let ((end (point))
+                    (bsf (progn (beginning-of-line)
           (smie-indent-forward-token)
-          (let ((bsf (point))
+                                (point)))
                 (gain 0)
                 curcol)
-            (while (<= (setq curcol (current-column)) fc)
+                (while (and (<= (point) end)
+                            (<= (setq curcol (current-column)) fc))
               ;; FIXME?  `smie-indent-calculate' can (and often will)
-              ;; return a result that actually depends on the presence/absence
-              ;; of a newline, so the gain computed here may not be accurate,
-              ;; but in practice it seems to works well enough.
+                  ;; return a result that actually depends on the
+                  ;; presence/absence of a newline, so the gain computed here
+                  ;; may not be accurate, but in practice it seems to works
+                  ;; well enough.
               (let* ((newcol (smie-indent-calculate))
                      (newgain (- curcol newcol)))
                 (when (> newgain gain)
@@ -1654,8 +1656,9 @@
               (smie-indent-forward-token))
             (when (> gain 0)
               (goto-char bsf)
-              (newline-and-indent)))))
-       (t (do-auto-fill))))))
+                  (newline-and-indent)
+                  'done))))
+          (do-auto-fill)))))

 (defun smie-setup (grammar rules-function &rest keywords)