Make TAB work in makefile mode when transient mark mode is on

* lisp/progmodes/make-mode.el (makefile-mode): Insert a tab
instead of removing it (bug#37087).

diff --git a/lisp/progmodes/make-mode.el b/lisp/progmodes/make-mode.el
index 91307f6c09f8dbe8902fde0e85d169c929a79752..1a1dc3aee9aa637b4c00c6bcacd0a3a3abff8bbb 100644 (file)
--- a/lisp/progmodes/make-mode.el
+++ b/lisp/progmodes/make-mode.el
@@ -889,7 +889,7 @@ Makefile mode can be configured by modifying the following variables:
   (setq-local comment-start-skip "#+[ \t]*")
 
   ;; Make sure TAB really inserts \t.
-  (setq-local indent-line-function 'indent-to-left-margin)
+  (setq-local indent-line-function #'insert-tab)
 
   ;; Real TABs are important in makefiles
   (setq indent-tabs-mode t))