[Emacs-diffs] emacs-26 607cc4e 2/8: Define cl-type-definition button type as needed (Bug#28899)

[Noam Postavsky]

branch: emacs-26
commit 607cc4e24a08cfe4a14db9d1387dfb23ba94044c
Author: Noam Postavsky <address@hidden>
Commit: Noam Postavsky <address@hidden>

    Define cl-type-definition button type as needed (Bug#28899)
    
    * lisp/emacs-lisp/eieio-opt.el (eieio-help-constructor): Require
    `cl-extra' before using the `cl-type-definition' button type.
---
 lisp/emacs-lisp/eieio-opt.el | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lisp/emacs-lisp/eieio-opt.el b/lisp/emacs-lisp/eieio-opt.el
index dbec48d..eeb0bc9 100644
--- a/lisp/emacs-lisp/eieio-opt.el
+++ b/lisp/emacs-lisp/eieio-opt.el
@@ -142,7 +142,10 @@ are not abstract."
              (find-lisp-object-file-name ctr def)))
       (when location
        (insert (substitute-command-keys " in `"))
-       (help-insert-xref-button
+       ;; The `cl-type-definition' button type can't be autoloaded
+       ;; due to circularity during bootstrap (Bug#28899).
+        (require 'cl-extra)
+        (help-insert-xref-button
         (help-fns-short-filename location)
         'cl-type-definition ctr location 'define-type)
        (insert (substitute-command-keys "'")))