* lisp/emacs-lisp/smie.el (smie-auto-fill): Rework to be more robust.

(smie-setup): Use add-function to set it.

* lisp/progmodes/octave.el (octave-smie-rules): Return nil rather than
0 after a semi-colon; it works better for smie-auto-fill.
(octave--indent-new-comment-line): New function.
(octave-indent-new-comment-line): Use it (indirectly).
(octave-mode): Don't disable smie-auto-fill.  Use add-function to
modify comment-line-break-function.

4 files changed, 94 insertions, 75 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a8d79f958d3..2495620ef1c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,15 @@
+2013-05-24  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * progmodes/octave.el (octave-smie-rules): Return nil rather than
+        0 after a semi-colon; it works better for smie-auto-fill.
+        (octave--indent-new-comment-line): New function.
+        (octave-indent-new-comment-line): Use it (indirectly).
+        (octave-mode): Don't disable smie-auto-fill.  Use add-function to
+        modify comment-line-break-function.
+
+        * emacs-lisp/smie.el (smie-auto-fill): Rework to be more robust.
+        (smie-setup): Use add-function to set it.
+
 2013-05-24  Sam Steingold  <sds@gnu.org>
 
         * sort.el (delete-duplicate-lines): Accept an optional `keep-blanks'
diff --git a/lisp/emacs-lisp/smie.el b/lisp/emacs-lisp/smie.el
index cb93cdf8dc6..9e338a0f4be 100644
--- a/lisp/emacs-lisp/smie.el
+++ b/lisp/emacs-lisp/smie.el
@@ -1735,37 +1735,45 @@ to which that point should be aligned, if we were to reindent it.")
           (save-excursion (indent-line-to indent))
         (indent-line-to indent)))))
 
-(defun smie-auto-fill ()
+(defun smie-auto-fill (do-auto-fill)
   (let ((fc (current-fill-column)))
-    (while (and fc (> (current-column) fc))
-      (or (unless (or (nth 8 (save-excursion
-                               (syntax-ppss (line-beginning-position))))
-                      (nth 8 (syntax-ppss)))
-            (save-excursion
-              (let ((end (point))
-                    (bsf (progn (beginning-of-line)
+    (when (and fc (> (current-column) fc))
+      ;; The loop below presumes BOL is outside of strings or comments.  Also,
+      ;; sometimes we prefer to fill the comment than the code around it.
+      (unless (or (nth 8 (save-excursion
+                           (syntax-ppss (line-beginning-position))))
+                  (nth 4 (save-excursion
+                           (move-to-column fc)
+                           (syntax-ppss))))
+        (while
+            (and (with-demoted-errors
+                   (save-excursion
+                     (let ((end (point))
+                           (bsf nil)    ;Best-so-far.
+                           (gain 0))
+                       (beginning-of-line)
+                       (while (progn
                                 (smie-indent-forward-token)
-                                (point)))
-                    (gain 0)
-                    curcol)
-                (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.
-                  (let* ((newcol (smie-indent-calculate))
-                         (newgain (- curcol newcol)))
-                    (when (> newgain gain)
-                      (setq gain newgain)
-                      (setq bsf (point))))
-                  (smie-indent-forward-token))
-                (when (> gain 0)
-                  (goto-char bsf)
-                  (newline-and-indent)
-                  'done))))
-          (do-auto-fill)))))
+                                (and (<= (point) end)
+                                     (<= (current-column) fc)))
+                         ;; FIXME?  `smie-indent-calculate' can (and often
+                         ;; does) 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 work well enough.
+                         (skip-chars-forward " \t")
+                         (let* ((newcol (smie-indent-calculate))
+                                (newgain (- (current-column) newcol)))
+                           (when (> newgain gain)
+                             (setq gain newgain)
+                             (setq bsf (point)))))
+                       (when (> gain 0)
+                         (goto-char bsf)
+                         (newline-and-indent)
+                         'done))))
+                 (> (current-column) fc))))
+      (when (> (current-column) fc)
+        (funcall do-auto-fill)))))
 
 
 (defun smie-setup (grammar rules-function &rest keywords)
@@ -1775,12 +1783,11 @@ RULES-FUNCTION is a set of indentation rules for use on `smie-rules-function'.
 KEYWORDS are additional arguments, which can use the following keywords:
 - :forward-token FUN
 - :backward-token FUN"
-  (set (make-local-variable 'smie-rules-function) rules-function)
-  (set (make-local-variable 'smie-grammar) grammar)
-  (set (make-local-variable 'indent-line-function) 'smie-indent-line)
-  (set (make-local-variable 'normal-auto-fill-function) 'smie-auto-fill)
-  (set (make-local-variable 'forward-sexp-function)
-       'smie-forward-sexp-command)
+  (setq-local smie-rules-function rules-function)
+  (setq-local smie-grammar grammar)
+  (setq-local indent-line-function #'smie-indent-line)
+  (add-function :around (local 'normal-auto-fill-function) #'smie-auto-fill)
+  (setq-local forward-sexp-function #'smie-forward-sexp-command)
   (while keywords
     (let ((k (pop keywords))
           (v (pop keywords)))
@@ -1792,30 +1799,26 @@ KEYWORDS are additional arguments, which can use the following keywords:
         (_ (message "smie-setup: ignoring unknown keyword %s" k)))))
   (let ((ca (cdr (assq :smie-closer-alist grammar))))
     (when ca
-      (set (make-local-variable 'smie-closer-alist) ca)
+      (setq-local smie-closer-alist ca)
       ;; Only needed for interactive calls to blink-matching-open.
-      (set (make-local-variable 'blink-matching-check-function)
-           #'smie-blink-matching-check)
+      (setq-local blink-matching-check-function #'smie-blink-matching-check)
       (unless smie-highlight-matching-block-mode
         (add-hook 'post-self-insert-hook
                   #'smie-blink-matching-open 'append 'local))
-      (set (make-local-variable 'smie-blink-matching-triggers)
-           (append smie-blink-matching-triggers
-                   ;; Rather than wait for SPC to blink, try to blink as
-                   ;; soon as we type the last char of a block ender.
-                   (let ((closers (sort (mapcar #'cdr smie-closer-alist)
-                                        #'string-lessp))
-                         (triggers ())
-                         closer)
-                     (while (setq closer (pop closers))
-                       (unless (and closers
-                                    ;; FIXME: this eliminates prefixes of other
-                                    ;; closers, but we should probably
-                                    ;; eliminate prefixes of other keywords
-                                    ;; as well.
-                                    (string-prefix-p closer (car closers)))
-                         (push (aref closer (1- (length closer))) triggers)))
-                     (delete-dups triggers)))))))
+      ;; Setup smie-blink-matching-triggers.  Rather than wait for SPC to
+      ;; blink, try to blink as soon as we type the last char of a block ender.
+      (let ((closers (sort (mapcar #'cdr smie-closer-alist) #'string-lessp))
+            (triggers ())
+            closer)
+        (while (setq closer (pop closers))
+          (unless
+              ;; FIXME: this eliminates prefixes of other closers, but we
+              ;; should probably eliminate prefixes of other keywords as well.
+              (and closers (string-prefix-p closer (car closers)))
+            (push (aref closer (1- (length closer))) triggers)))
+        (setq-local smie-blink-matching-triggers
+                    (append smie-blink-matching-triggers
+                            (delete-dups triggers)))))))
 
 
 (provide 'smie)
diff --git a/lisp/progmodes/octave.el b/lisp/progmodes/octave.el
index 62bef6dfdea..243e3198584 100644
--- a/lisp/progmodes/octave.el
+++ b/lisp/progmodes/octave.el
@@ -438,7 +438,7 @@ Non-nil means always go to the next Octave code line after sending."
          (smie-rule-parent octave-block-offset)
        ;; For (invalid) code between switch and case.
        ;; (if (smie-parent-p "switch") 4)
-       0))))
+       nil))))
 
 (defun octave-indent-comment ()
   "A function for `smie-indent-functions' (which see)."
@@ -552,11 +552,10 @@ definitions can also be stored in files and used in batch mode."
   (setq-local paragraph-ignore-fill-prefix t)
   (setq-local fill-paragraph-function 'octave-fill-paragraph)
 
-  ;; Use `smie-auto-fill' after fixing bug#14381.
-  (setq-local normal-auto-fill-function 'do-auto-fill)
   (setq-local fill-nobreak-predicate
               (lambda () (eq (octave-in-string-p) ?')))
-  (setq-local comment-line-break-function #'octave-indent-new-comment-line)
+  (add-function :around (local 'comment-line-break-function)
+                #'octave--indent-new-comment-line)
 
   (setq font-lock-defaults '(octave-font-lock-keywords))
 
@@ -1112,11 +1111,16 @@ q: Don't fix\n" func file))
 ;;; Indentation
 
 (defun octave-indent-new-comment-line (&optional soft)
+  ;; FIXME: C-M-j should probably be bound globally to a function like
+  ;; this one.
   "Break Octave line at point, continuing comment if within one.
 Insert `octave-continuation-string' before breaking the line
 unless inside a list.  Signal an error if within a single-quoted
 string."
   (interactive)
+  (funcall comment-line-break-function soft))
+
+(defun octave--indent-new-comment-line (orig &rest args)
   (cond
    ((octave-in-comment-p) nil)
    ((eq (octave-in-string-p) ?')
@@ -1128,7 +1132,7 @@ string."
     (unless (and (cadr (syntax-ppss))
                  (eq (char-after (cadr (syntax-ppss))) ?\())
       (insert " " octave-continuation-string))))
-  (indent-new-comment-line soft)
+  (apply orig args)
   (indent-according-to-mode))
 
 (define-obsolete-function-alias
diff --git a/test/indent/octave.m b/test/indent/octave.m
index bc7784f1ba2..98be02acd74 100644
--- a/test/indent/octave.m
+++ b/test/indent/octave.m
@@ -1089,13 +1089,13 @@ function [pkg_idx_struct] = parse_pkg_idx (packdir)
 
   while (! feof (fid) || line != -1)
     if (! any (! isspace (line)) || line(1) == "#" || any (line == "="))
-    ## Comments,  blank lines or comments about unimplemented
-    ## functions: do nothing
-    ## FIXME: probably comments and pointers to external functions
-    ## could be treated better when printing to screen?
+      ## Comments,  blank lines or comments about unimplemented
+      ## functions: do nothing
+      ## FIXME: probably comments and pointers to external functions
+      ## could be treated better when printing to screen?
     elseif (! isempty (strfind (line, ">>")))
-    ## Skip package name and description as they are in DESCRIPTION
-    ## already.
+      ## Skip package name and description as they are in DESCRIPTION
+      ## already.
     elseif (! isspace (line(1)))
       ## Category.
       if (! isempty (pkg_idx_struct{cat_num}.functions))
@@ -1658,7 +1658,7 @@ function desc = get_description (filename)
   line = fgetl (fid);
   while (line != -1)
     if (line(1) == "#")
-    ## Comments, do nothing.
+      ## Comments, do nothing.
     elseif (isspace(line(1)))
       ## Continuation lines
       if (exist ("keyword", "var") && isfield (desc, keyword))
@@ -1752,9 +1752,9 @@ function deps_cell = fix_depends (depends)
       endif
       version  = fix_version (parts{2});
 
-    ## If no version is specified for the dependency
-    ## we say that the version should be greater than
-    ## or equal to "0.0.0".
+      ## If no version is specified for the dependency
+      ## we say that the version should be greater than
+      ## or equal to "0.0.0".
     else
       package = tolower (strip (dep));
       operator = ">=";
@@ -1859,7 +1859,7 @@ function bad_deps = get_unsatisfied_deps (desc, installed_pkgs_lst)
       if (! compare_versions (OCTAVE_VERSION, dep.version, dep.operator))
         bad_deps{end+1} = dep;
       endif
-    ## Is the current dependency not Octave?
+      ## Is the current dependency not Octave?
     else
       ok = false;
       for i = 1:length (installed_pkgs_lst)
@@ -2025,7 +2025,7 @@ function load_packages (files, handle_deps, local_list, global_list)
   ## Load all.
   if (length (files) == 1 && strcmp (files{1}, "all"))
     idx = [1:length(installed_pkgs_lst)];
-  ## Load auto.
+    ## Load auto.
   elseif (length (files) == 1 && strcmp (files{1}, "auto"))
     idx = [];
     for i = 1:length (installed_pkgs_lst)
@@ -2033,7 +2033,7 @@ function load_packages (files, handle_deps, local_list, global_list)
         idx (end + 1) = i;
       endif
     endfor
-  ## Load package_name1 ...
+    ## Load package_name1 ...
   else
     idx = [];
     for i = 1:length (files)
@@ -2100,8 +2100,8 @@ function unload_packages (files, handle_deps, local_list, global_list)
     idx = strcmp (p, d);
     if (any (idx))
       rmpath (d);
-    ## FIXME: We should also check if we need to remove items from
-    ## EXEC_PATH.
+      ## FIXME: We should also check if we need to remove items from
+      ## EXEC_PATH.
     endif
   endfor
 endfunction