(describe-key, describe-key-briefly): For a mouse click,

go to its buffer and position before looking up the key.

1 files changed, 54 insertions, 19 deletions

diff --git a/lisp/help.el b/lisp/help.el
index d81e433f755..e416fd3d887 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -167,12 +167,29 @@ Commands:
     (and (symbolp type)
          (memq 'down (event-modifiers type))
          (read-event)))
-  (let ((defn (key-binding key)))
-    (if (or (null defn) (integerp defn))
-        (message "%s is undefined" (key-description key))
-      (message "%s runs the command %s"
-               (key-description key)
-               (if (symbolp defn) defn (prin1-to-string defn))))))
+  (save-excursion
+    (let ((modifiers (event-modifiers (aref key 0)))
+          window position)
+      ;; For a mouse button event, go to the button it applies to
+      ;; to get the right key bindings.  And go to the right place
+      ;; in case the keymap depends on where you clicked.
+      (if (or (memq 'click modifiers) (memq 'down modifiers)
+              (memq 'drag modifiers))
+          (setq window (posn-window (event-start (aref key 0)))
+                position (posn-point (event-start (aref key 0)))))
+      (if (windowp window)
+          (progn
+            (set-buffer (window-buffer window))
+            (goto-char position)))
+      ;; Ok, now look up the key and name the command.
+      (let ((defn (key-binding key)))
+        (if (or (null defn) (integerp defn))
+            (message "%s is undefined" (key-description key))
+          (message (if (windowp window)
+                       "%s at that spot runs the command %s"
+                     "%s runs the command %s")
+                   (key-description key)
+                   (if (symbolp defn) defn (prin1-to-string defn))))))))
 
 (defun print-help-return-message (&optional function)
   "Display or return message saying how to restore windows after help command.
@@ -255,19 +272,37 @@ If FUNCTION is nil, applies `message' to it, thus printing it."
     (and (symbolp type)
          (memq 'down (event-modifiers type))
          (read-event)))
-  (let ((defn (key-binding key)))
-    (if (or (null defn) (integerp defn))
-        (message "%s is undefined" (key-description key))
-      (with-output-to-temp-buffer "*Help*"
-        (prin1 defn)
-        (princ ":\n")
-        (if (documentation defn)
-            (princ (documentation defn))
-          (princ "not documented"))
-        (save-excursion
-          (set-buffer standard-output)
-          (help-mode))
-        (print-help-return-message)))))
+  (save-excursion
+    (let ((modifiers (event-modifiers (aref key 0)))
+          window position)
+      ;; For a mouse button event, go to the button it applies to
+      ;; to get the right key bindings.  And go to the right place
+      ;; in case the keymap depends on where you clicked.
+      (if (or (memq 'click modifiers) (memq 'down modifiers)
+              (memq 'drag modifiers))
+          (setq window (posn-window (event-start (aref key 0)))
+                position (posn-point (event-start (aref key 0)))))
+      (if (windowp window)
+          (progn
+            (set-buffer (window-buffer window))
+            (goto-char position)))
+      (let ((defn (key-binding key)))
+        (if (or (null defn) (integerp defn))
+            (message "%s is undefined" (key-description key))
+          (with-output-to-temp-buffer "*Help*"
+            (princ (key-description key))
+            (if (windowp window)
+                (princ " at that spot"))
+            (princ " runs the command ")
+            (prin1 defn)
+            (princ ":\n")
+            (if (documentation defn)
+                (princ (documentation defn))
+              (princ "not documented"))
+            (save-excursion
+              (set-buffer standard-output)
+              (help-mode))
+            (print-help-return-message)))))))
 
 (defun describe-mode ()
   "Display documentation of current major mode and minor modes.