Small smie.el doc and fix

* lisp/emacs-lisp/smie.el (smie-config-guess): Doc fix.
Explicit error if no grammar.
(smie-config-save): Doc fix.  Fix quote typo.

* etc/NEWS: Related edit.

3 files changed, 21 insertions, 6 deletions

diff --git a/etc/NEWS b/etc/NEWS
index d27f5655eb5..c1342ebfea1 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -896,9 +896,14 @@ All non-ancient Bash versions support this option.
 ---
 *** `sh-mode' now has its own setting for `add-log-current-defun-function'.
 
-** SMIE indentation can be customized via `smie-config'.
-Emacs can learn the appropriate indentation settings if you provide it
-with an indented sample file.
+** SMIE
+
+*** You can customize the indentation of modes that use SMIE via `smie-config'.
+The command `smie-config-guess' can help you derive the appropriate
+indentation settings, if you provide it with an indented sample file.
+Use `smie-config-save' to save the result.
+
+*** New commands `smie-config-show-indent' and `smie-config-set-indent'.
 
 ---
 ** SQL mode
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e75f2cc3190..a576c69fc07 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2014-03-04  Glenn Morris  <rgm@gnu.org>
+
+        * emacs-lisp/smie.el (smie-config-guess): Doc fix.
+        Explicit error if no grammar.
+        (smie-config-save): Doc fix.  Fix quote typo.
+
 2014-03-04  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * progmodes/cc-mode.el (c-initialize-cc-mode): Only hook into
diff --git a/lisp/emacs-lisp/smie.el b/lisp/emacs-lisp/smie.el
index 02a41cddfab..e65f873b874 100644
--- a/lisp/emacs-lisp/smie.el
+++ b/lisp/emacs-lisp/smie.el
@@ -2149,8 +2149,11 @@ position corresponding to each rule."
         rules))))
 
 (defun smie-config-guess ()
-  "Try and figure out this buffer's indentation settings."
+  "Try and figure out this buffer's indentation settings.
+To save the result for future sessions, use `smie-config-save'."
   (interactive)
+  (if (eq smie-grammar 'unset)
+      (user-error "This buffer does not seem to be using SMIE"))
   (let ((config (smie-config--guess (point-min) (point-max))))
     (cond
      ((null config) (message "Nothing to change"))
@@ -2168,7 +2171,8 @@ position corresponding to each rule."
       (message "Rules guessed: %S" config)))))
 
 (defun smie-config-save ()
-  "Save local rules for use with this major mode."
+  "Save local rules for use with this major mode.
+One way to generate local rules is the command `smie-config-guess'."
   (interactive)
   (cond
    ((null smie-config--buffer-local)
@@ -2190,7 +2194,7 @@ position corresponding to each rule."
           (setcdr existing config)
         (push (cons major-mode config) smie-config))
       (setq smie-config--mode-local config)
-      (kill-local-variable smie-config--buffer-local)
+      (kill-local-variable 'smie-config--buffer-local)
       (customize-mark-as-set 'smie-config)))))
 
 (provide 'smie)