master 0a6a25320eb: Merge from origin/emacs-29

[Jim Porter]

branch: master
commit 0a6a25320eb671816087164b17e6ecb68632303c
Merge: 1bf92d91950 1e8322bb26e
Author: Jim Porter <jporterbugs@gmail.com>
Commit: Jim Porter <jporterbugs@gmail.com>

    Merge from origin/emacs-29
    
    1e8322bb26e Fix handling of 'byte-compile-ignore-files' when nil
---
 lisp/emacs-lisp/bytecomp.el | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index f0656628236..f6ba6ff9ea0 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1976,7 +1976,9 @@ also be compiled."
     (let ((directories (list default-directory))
          (default-directory default-directory)
           (ignore-files-regexp
-           (mapconcat #'identity byte-compile-ignore-files "\\|"))
+           (if byte-compile-ignore-files
+               (mapconcat #'identity byte-compile-ignore-files "\\|")
+             regexp-unmatchable))
          (skip-count 0)
          (fail-count 0)
          (file-count 0)