master 70f7f0b: button-buttonize doc string clarification

[Lars Ingebrigtsen]

branch: master
commit 70f7f0b1fd6576752f4cfef8f2e597f3e8a56123
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    button-buttonize doc string clarification
    
    * lisp/button.el (button-buttonize): Clarify what happens when
    DATA isn't present.
---
 lisp/button.el | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lisp/button.el b/lisp/button.el
index 8dbb763..a6f7043 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -615,7 +615,9 @@ button at point is the button to describe."
 
 (defun button-buttonize (string callback &optional data)
   "Make STRING into a button and return it.
-When clicked, CALLBACK will be called with the optional DATA parameter."
+When clicked, CALLBACK will be called with the DATA as the
+function argument.  If DATA isn't present (or is nil), the button
+itself will be used instead as the function argument."
   (propertize string
               'face 'button
               'button t