* mouse-sel.el (mouse-sel-follow-link-p): Use event position

instead of buffer position for `mouse-on-link-p'.

* mouse.el (mouse-posn-property): New function looking up the
properties at a click position in overlays and text properties in
either buffer or strings.
(mouse-on-link-p): Use `mouse-posn-property' to streamline lookup
of both `follow-link' as well as `mouse-face' properties.
(mouse-drag-track): Check `mouse-on-link-p' on event position, not
buffer position.

* help.el (describe-key-briefly): When reading a down-event on
mode lines or scroll bar, swallow the following up event, too.
Use the new mouse sensitity of `key-binding' for lookup.
(describe-key): The same here.

1 files changed, 132 insertions, 133 deletions

diff --git a/lisp/help.el b/lisp/help.el
index d5682512b2d..72a45ec15bf 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -567,11 +567,16 @@ temporarily enables it to allow getting help on disabled items and buttons."
              (menu-bar-update-yank-menu "(any string)" nil))
            (setq key (read-key-sequence "Describe key (or click or menu item): "))
            ;; If KEY is a down-event, read and discard the
-           ;; corresponding up-event.
-           (if (and (vectorp key)
-                    (eventp (elt key 0))
-                    (memq 'down (event-modifiers (elt key 0))))
-               (read-event))
+           ;; corresponding up-event.  Note that there are also
+           ;; down-events on scroll bars and mode lines: the actual
+           ;; event then is in the second element of the vector.
+           (and (vectorp key)
+                (or (and (eventp (aref key 0))
+                         (memq 'down (event-modifiers (aref key 0))))
+                    (and (> (length key) 1)
+                         (eventp (aref key 1))
+                         (memq 'down (event-modifiers (aref key 1)))))
+                (read-event))
            (list
             key
             (if current-prefix-arg (prefix-numeric-value current-prefix-arg))
@@ -582,45 +587,40 @@ temporarily enables it to allow getting help on disabled items and buttons."
          (fset 'yank-menu (cons 'keymap yank-menu))))))
   (if (numberp untranslated)
       (setq untranslated (this-single-command-raw-keys)))
-  (save-excursion
-    (let ((modifiers (event-modifiers (aref key 0)))
-          (standard-output (if insert (current-buffer) t))
-          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 t))
-            key-desc)
-        ;; Handle the case where we faked an entry in "Select and Paste" menu.
-        (if (and (eq defn nil)
-                 (stringp (aref key (1- (length key))))
-                 (eq (key-binding (substring key 0 -1)) 'yank-menu))
-            (setq defn 'menu-bar-select-yank))
-        ;; Don't bother user with strings from (e.g.) the select-paste menu.
-        (if (stringp (aref key (1- (length key))))
-            (aset key (1- (length key)) "(any string)"))
-        (if (and (> (length untranslated) 0)
-                 (stringp (aref untranslated (1- (length untranslated)))))
-            (aset untranslated (1- (length untranslated))
-                  "(any string)"))
-        ;; Now describe the key, perhaps as changed.
-        (setq key-desc (help-key-description key untranslated))
-        (if (or (null defn) (integerp defn) (equal defn 'undefined))
-            (princ (format "%s is undefined" key-desc))
-          (princ (format (if (windowp window)
-                             "%s at that spot runs the command %s"
-                           "%s runs the command %s")
-                         key-desc
-                         (if (symbolp defn) defn (prin1-to-string defn)))))))))
+  (let* ((event (if (and (symbolp (aref key 0))
+                         (> (length key) 1)
+                         (consp (aref key 1)))
+                    (aref key 1)
+                  (aref key 0)))
+         (modifiers (event-modifiers event))
+         (standard-output (if insert (current-buffer) t))
+         (mousep
+          (or (memq 'click modifiers) (memq 'down modifiers)
+              (memq 'drag modifiers))))
+    ;; Ok, now look up the key and name the command.
+    (let ((defn (key-binding key t))
+          key-desc)
+      ;; Handle the case where we faked an entry in "Select and Paste" menu.
+      (if (and (eq defn nil)
+               (stringp (aref key (1- (length key))))
+               (eq (key-binding (substring key 0 -1)) 'yank-menu))
+          (setq defn 'menu-bar-select-yank))
+      ;; Don't bother user with strings from (e.g.) the select-paste menu.
+      (if (stringp (aref key (1- (length key))))
+          (aset key (1- (length key)) "(any string)"))
+      (if (and (> (length untranslated) 0)
+               (stringp (aref untranslated (1- (length untranslated)))))
+          (aset untranslated (1- (length untranslated))
+                "(any string)"))
+      ;; Now describe the key, perhaps as changed.
+      (setq key-desc (help-key-description key untranslated))
+      (if (or (null defn) (integerp defn) (equal defn 'undefined))
+          (princ (format "%s is undefined" key-desc))
+        (princ (format (if mousep
+                           "%s at that spot runs the command %s"
+                         "%s runs the command %s")
+                       key-desc
+                       (if (symbolp defn) defn (prin1-to-string defn))))))))
 
 (defun describe-key (&optional key untranslated up-event)
   "Display documentation of the function invoked by KEY.
@@ -652,105 +652,104 @@ temporarily enables it to allow getting help on disabled items and buttons."
             (prefix-numeric-value current-prefix-arg)
             ;; If KEY is a down-event, read the corresponding up-event
             ;; and use it as the third argument.
-            (if (and (vectorp key)
-                     (eventp (elt key 0))
-                     (memq 'down (event-modifiers (elt key 0))))
-                (read-event))))
+            (and (vectorp key)
+                 (or (and (eventp (aref key 0))
+                          (memq 'down (event-modifiers (aref key 0))))
+                     (and (> (length key) 1)
+                          (eventp (aref key 1))
+                          (memq 'down (event-modifiers (aref key 1)))))
+                 (read-event))))
        ;; Put yank-menu back as it was, if we changed it.
        (when saved-yank-menu
          (setq yank-menu (copy-sequence saved-yank-menu))
          (fset 'yank-menu (cons 'keymap yank-menu))))))
   (if (numberp untranslated)
       (setq untranslated (this-single-command-raw-keys)))
-  (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)))))
-      (when (windowp window)
-            (set-buffer (window-buffer window))
-        (goto-char position))
-      (let ((defn (key-binding key t)))
-        ;; Handle the case where we faked an entry in "Select and Paste" menu.
-        (if (and (eq defn nil)
-                 (stringp (aref key (1- (length key))))
-                 (eq (key-binding (substring key 0 -1)) 'yank-menu))
-            (setq defn 'menu-bar-select-yank))
-        (if (or (null defn) (integerp defn) (equal defn 'undefined))
-            (message "%s is undefined" (help-key-description key untranslated))
-          (help-setup-xref (list #'describe-function defn) (interactive-p))
-          ;; Don't bother user with strings from (e.g.) the select-paste menu.
-          (if (stringp (aref key (1- (length key))))
-              (aset key (1- (length key)) "(any string)"))
-          (if (and untranslated
-                   (stringp (aref untranslated (1- (length untranslated)))))
-              (aset untranslated (1- (length untranslated))
-                    "(any string)"))
-          (with-output-to-temp-buffer (help-buffer)
-            (princ (help-key-description key untranslated))
-            (if (windowp window)
-                (princ " at that spot"))
-            (princ " runs the command ")
-            (prin1 defn)
-            (princ "\n   which is ")
-            (describe-function-1 defn)
-            (when up-event
-              (let ((type (event-basic-type up-event))
-                    (hdr "\n\n-------------- up event ---------------\n\n")
-                    defn sequence
-                    mouse-1-tricky mouse-1-remapped)
-                (setq sequence (vector up-event))
-                (when (and (eq type 'mouse-1)
-                           (windowp window)
-                           mouse-1-click-follows-link
-                           (not (eq mouse-1-click-follows-link 'double))
-                           (setq mouse-1-remapped
-                                 (with-current-buffer (window-buffer window)
-                                   (mouse-on-link-p (posn-point
-                                                     (event-start up-event))))))
-                  (setq mouse-1-tricky (and (integerp mouse-1-click-follows-link)
-                                            (> mouse-1-click-follows-link 0)))
-                  (cond ((stringp mouse-1-remapped)
-                         (setq sequence mouse-1-remapped))
-                        ((vectorp mouse-1-remapped)
-                         (setcar up-event (elt mouse-1-remapped 0)))
-                        (t (setcar up-event 'mouse-2))))
-                (setq defn (key-binding sequence))
-                (unless (or (null defn) (integerp defn) (equal defn 'undefined))
-                  (princ (if mouse-1-tricky
-                             "\n\n----------------- up-event (short click) ----------------\n\n"
-                           hdr))
-                  (setq hdr nil)
-                  (princ (symbol-name type))
-                  (if (windowp window)
+  (let* ((event (if (and (symbolp (aref key 0))
+                         (> (length key) 1)
+                         (consp (aref key 1)))
+                    (aref key 1)
+                  (aref key 0)))
+         (modifiers (event-modifiers event))
+         (mousep
+          (or (memq 'click modifiers) (memq 'down modifiers)
+              (memq 'drag modifiers))))
+    ;; Ok, now look up the key and name the command.
+
+    (let ((defn (key-binding key t)))
+      ;; Handle the case where we faked an entry in "Select and Paste" menu.
+      (if (and (eq defn nil)
+               (stringp (aref key (1- (length key))))
+               (eq (key-binding (substring key 0 -1)) 'yank-menu))
+          (setq defn 'menu-bar-select-yank))
+      (if (or (null defn) (integerp defn) (equal defn 'undefined))
+          (message "%s is undefined" (help-key-description key untranslated))
+        (help-setup-xref (list #'describe-function defn) (interactive-p))
+        ;; Don't bother user with strings from (e.g.) the select-paste menu.
+        (if (stringp (aref key (1- (length key))))
+            (aset key (1- (length key)) "(any string)"))
+        (if (and untranslated
+                 (stringp (aref untranslated (1- (length untranslated)))))
+            (aset untranslated (1- (length untranslated))
+                  "(any string)"))
+        (with-output-to-temp-buffer (help-buffer)
+          (princ (help-key-description key untranslated))
+          (if mousep
+              (princ " at that spot"))
+          (princ " runs the command ")
+          (prin1 defn)
+          (princ "\n   which is ")
+          (describe-function-1 defn)
+          (when up-event
+            (let ((type (event-basic-type up-event))
+                  (hdr "\n\n-------------- up event ---------------\n\n")
+                  defn sequence
+                  mouse-1-tricky mouse-1-remapped)
+              (setq sequence (vector up-event))
+              (when (and (eq type 'mouse-1)
+                         mouse-1-click-follows-link
+                         (not (eq mouse-1-click-follows-link 'double))
+                         (setq mouse-1-remapped
+                               (mouse-on-link-p (event-start up-event))))
+                (setq mouse-1-tricky (and (integerp mouse-1-click-follows-link)
+                                          (> mouse-1-click-follows-link 0)))
+                (cond ((stringp mouse-1-remapped)
+                       (setq sequence mouse-1-remapped))
+                      ((vectorp mouse-1-remapped)
+                       (setcar up-event (elt mouse-1-remapped 0)))
+                      (t (setcar up-event 'mouse-2))))
+              (setq defn (key-binding sequence nil nil (event-start up-event)))
+              (unless (or (null defn) (integerp defn) (equal defn 'undefined))
+                (princ (if mouse-1-tricky
+                           "\n\n----------------- up-event (short click) ----------------\n\n"
+                         hdr))
+                (setq hdr nil)
+                (princ (symbol-name type))
+                (if mousep
+                    (princ " at that spot"))
+                (if mouse-1-remapped
+                    (princ " is remapped to <mouse-2>\n  which" ))
+                (princ " runs the command ")
+                (prin1 defn)
+                (princ "\n   which is ")
+                (describe-function-1 defn))
+              (when mouse-1-tricky
+                (setcar up-event 'mouse-1)
+                (setq defn (key-binding (vector up-event) nil nil
+                                        (event-start up-event)))
+                (unless (or (null defn) (integerp defn) (eq defn 'undefined))
+                  (princ (or hdr
+                             "\n\n----------------- up-event (long click) ----------------\n\n"))
+                  (princ "Pressing mouse-1")
+                  (if mousep
                       (princ " at that spot"))
-                  (if mouse-1-remapped
-                      (princ " is remapped to <mouse-2>\n  which" ))
+                  (princ (format " for longer than %d milli-seconds\n"
+                                 mouse-1-click-follows-link))
                   (princ " runs the command ")
                   (prin1 defn)
                   (princ "\n   which is ")
-                  (describe-function-1 defn))
-                (when mouse-1-tricky
-                  (setcar up-event 'mouse-1)
-                  (setq defn (key-binding (vector up-event)))
-                  (unless (or (null defn) (integerp defn) (eq defn 'undefined))
-                    (princ (or hdr
-                               "\n\n----------------- up-event (long click) ----------------\n\n"))
-                    (princ "Pressing mouse-1")
-                    (if (windowp window)
-                        (princ " at that spot"))
-                    (princ (format " for longer than %d milli-seconds\n"
-                                   mouse-1-click-follows-link))
-                    (princ " runs the command ")
-                    (prin1 defn)
-                    (princ "\n   which is ")
-                    (describe-function-1 defn)))))
-            (print-help-return-message)))))))
+                  (describe-function-1 defn)))))
+          (print-help-return-message))))))
 
 (defun describe-mode (&optional buffer)
   "Display documentation of current major mode and minor modes.