derived-mode-make-docstring tweak for bug#11277

* lisp/emacs-lisp/derived.el (derived-mode-make-docstring):
Don't mention "abbrev" or "syntax" if nil.

2 files changed, 30 insertions, 9 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b6d7c082a88..6a1ac6f680d 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-27  Glenn Morris  <rgm@gnu.org>
+
+        * emacs-lisp/derived.el (derived-mode-make-docstring):
+        Don't mention "abbrev" or "syntax" if nil.  (Bug#11277)
+
 2012-11-27  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * textmodes/table.el (table-insert): Don't use `symbol-name' on
diff --git a/lisp/emacs-lisp/derived.el b/lisp/emacs-lisp/derived.el
index 8c8d37b2194..f4b79eb3016 100644
--- a/lisp/emacs-lisp/derived.el
+++ b/lisp/emacs-lisp/derived.el
@@ -295,16 +295,32 @@ is not very useful."
       ;; Use a default docstring.
       (setq docstring
             (if (null parent)
-                (format "Major-mode.
-Uses keymap `%s', abbrev table `%s' and syntax-table `%s'." map abbrev syntax)
+                ;; FIXME filling.
+                (format "Major-mode.\nUses keymap `%s'%s%s." map
+                        (if abbrev (format "%s abbrev table `%s'"
+                                           (if syntax "," " and") abbrev) "")
+                        (if syntax (format " and syntax-table `%s'" syntax) ""))
               (format "Major mode derived from `%s' by `define-derived-mode'.
-It inherits all of the parent's attributes, but has its own keymap,
-abbrev table and syntax table:
-
-  `%s', `%s' and `%s'
-
-which more-or-less shadow %s's corresponding tables."
-                      parent map abbrev syntax parent))))
+It inherits all of the parent's attributes, but has its own keymap%s:
+
+  `%s'%s
+
+which more-or-less shadow%s %s's corresponding table%s."
+                      parent
+                      (cond ((and abbrev syntax)
+                             ",\nabbrev table and syntax table")
+                            (abbrev "\nand abbrev table")
+                            (syntax "\nand syntax table")
+                            (t ""))
+                      map
+                      (cond ((and abbrev syntax)
+                             (format ", `%s' and `%s'" abbrev syntax))
+                            ((or abbrev syntax)
+                             (format " and `%s'" (or abbrev syntax)))
+                            (t ""))
+                      (if (or abbrev syntax) "" "s")
+                      parent
+                      (if (or abbrev syntax) "s" "")))))
 
     (unless (string-match (regexp-quote (symbol-name hook)) docstring)
       ;; Make sure the docstring mentions the mode's hook.