"Indenting region..."

[edrx]

Hi! Help!

Sometimes when I try to indent some text in comments with `M-q'
lua-mode says "Indenting region...", and it takes a long time (in big
files) and reindents the whole file in its default style, that is not
the style that I usually use... I took a look at the source code of
lua-mode.el and at the binding for `M-q' (`prog-fill-reindent-defun')
and I couldn't find an obvious fix - I _guess_ that what is happening
is that sometimes when the transient mark is disabled and the point is
inside a multi-line comment in which all the lines start with "--"
then lua-mode.el thinks that the region is the whole file, and tells
that to prog-fill-reindent-defun...

1) Is there an easy fix for that? Like setting some variable?

2) Do you need a reproducible example that can be run in an emacs -Q?
I can prepare one and a video if that helps...