master 6574943: Revert make-text-button string copy

[Paul Eggert]

branch: master
commit 65749436d03fd0b9e379dcc06cc678522c6960cf
Author: Paul Eggert <eggert@cs.ucla.edu>
Commit: Paul Eggert <eggert@cs.ucla.edu>

    Revert make-text-button string copy
    
    * lisp/button.el (make-text-button): Don’t make a copy of
    a button’s string label.  This reverts the change made in
    2020-05-17T05:23:28Z!eggert@cs.ucla.edu, which broke SLY.
    Problem reported by João Távora in:
    https://lists.gnu.org/r/emacs-devel/2020-06/msg00117.html
    However, we’ll need a better fix for this once string
    literals become contents, if SLY uses string constants
    for text button labels.
---
 lisp/button.el | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lisp/button.el b/lisp/button.el
index a91b048..3a6a6de 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -349,7 +349,6 @@ Also see `insert-text-button'."
         (or (plist-member properties 'type)
             (plist-member properties :type))))
     (when (stringp beg)
-      (setq beg (copy-sequence beg)) ;; In case BEG is not mutable.
       (setq object beg beg 0 end (length object)))
     ;; Disallow setting the `category' property directly.
     (when (plist-get properties 'category)