Allow clicking mouse-3 on mode line to change coding system.

* lisp/bindings.el (mode-line-coding-system-map): Allow using mouse-3
to invoke set-buffer-file-coding-system.
(mode-line-mule-info-help-echo): Update help text.

Fixes: debbugs:289

etc/NEWS

@@ -93,6 +93,9 @@ Use "coding: raw-text" instead.
 (shown in a tooltip or in the echo area) for any part of the mode line
 that does not have its own specialized help text.
 
+*** You can now click mouse-3 in the coding system indicator to
+invokes `set-buffer-file-coding-system'.
+
 
 * Editing Changes in Emacs 24.2
 

lisp/ChangeLog

@@ -12,6 +12,9 @@
 	(mode-line-mule-info, mode-line-modified): Use them.
 	(mode-line-eol-desc, propertized-buffer-identification):
 	Consistency fixes for help text.
+	(mode-line-coding-system-map): Allow using mouse-3 to invoke
+	set-buffer-file-coding-system (Bug#289).
+	(mode-line-mule-info-help-echo): Update help text.
 2012-06-02  Stefan Monnier  <monnier@iro.umontreal.ca>

lisp/bindings.el

@@ -88,6 +88,12 @@ corresponding to the mode line clicked."
 	  (when (and enable-multibyte-characters
 		     buffer-file-coding-system)
 	    (describe-coding-system buffer-file-coding-system)))))
+    (define-key map [mode-line mouse-3]
+      (lambda (e)
+	(interactive "e")
+	(save-selected-window
+	  (select-window (posn-window (event-start e)))
+	  (call-interactively 'set-buffer-file-coding-system))))
     (purecopy map))
   "Local keymap for the coding-system part of the mode line.")
 
@@ -153,7 +159,8 @@ is displayed first.")
   (with-current-buffer (window-buffer window)
     (if buffer-file-coding-system
 	(format "Buffer coding system (%s): %s
-mouse-1: Describe coding system"
+mouse-1: Describe coding system
+mouse-3: Set coding system"
 		(if enable-multibyte-characters "multi-byte" "unibyte")
 		(symbol-name buffer-file-coding-system))
       "Buffer coding system: none specified")))