New user option 'tab-line-tabs-buffer-group-function'

* lisp/tab-line.el (tab-line-tabs-buffer-group-function):
Turn defvar into defcustom with the default value
'tab-line-tabs-buffer-group-by-mode'.
(tab-line-tabs-buffer-group-by-mode): New function with body from
'tab-line-tabs-buffer-group-name'.
(tab-line-tabs-buffer-group-by-project): New function.
(tab-line-tabs-buffer-groups): Use fallback name "No group" instead of "All".

1 files changed, 5 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index ed5db3a01a3..da809096d94 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -364,6 +364,11 @@ By default it contains a keybinding 'C-TAB' to switch tabs,
 but only when 'C-TAB' is not bound globally.  You can unbind it
 if it conflicts with 'C-TAB' in other modes.
 
+---
+*** New user option 'tab-line-tabs-buffer-group-function'.
+It provides two choices to group tab buffers by major mode
+and by project name.
+
 +++
 ** New optional argument for modifying directory-local variables.
 The commands 'add-dir-local-variable', 'delete-dir-local-variable' and