Allow commenting out white space lines in latex-mode

* lisp/newcomment.el (comment-region-default-1): Allow commenting
out whitespace-only regions (bug#41793).

* lisp/textmodes/tex-mode.el (latex--comment-region): Use it.
(latex-mode): Set a comment style shim.

1 files changed, 6 insertions, 1 deletions

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index c4e4864da17..ce665e61656 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1169,7 +1169,12 @@ subshell is initiated, `tex-shell-hook' is run."
   (setq-local outline-regexp latex-outline-regexp)
   (setq-local outline-level #'latex-outline-level)
   (setq-local forward-sexp-function #'latex-forward-sexp)
-  (setq-local skeleton-end-hook nil))
+  (setq-local skeleton-end-hook nil)
+  (setq-local comment-region-function #'latex--comment-region)
+  (setq-local comment-style 'plain))
+
+(defun latex--comment-region (beg end &optional arg)
+  (comment-region-default-1 beg end arg t))
 
 ;;;###autoload
 (define-derived-mode slitex-mode latex-mode "SliTeX"