Re: Replacing huge hidden selection when pasting text

[Kaushal Modi]

> When I say "invisible region", I mean that it appears just like normal
text.

Exactly, that's what I demonstrated in that screen shot. When the color
resolution is very low, the selected region, the "sample", looks
unselected, like rest of the text in the buffer.

> Face: region (sample) (customize this face)

I just wanted to know if the "sample" text in the above line looked
distinguished, with a different background than the rest. I see that the
Background value is blue3 (but I don't know what your default background
value is). Pasting that text here would not justify that. So I linked to
the screenshot images I took.  If you do see that "sample" text with a
different background, which more likely is, as you mentioned,

> If I explicitly define a region with e.g. SHIFT+arrow key, it is always
perfectly visible.

, then we can throw out this reason for invisibility out of consideration.

So it boils down to filing an emacs bug report as others mentioned, with a
definitive recipe of how to recreate this problem in an emacs -Q session.
FWIW, I have never this issue. I always have transient-mark-mode and
delete-selection-mode enabled. In my emacs version (latest build from
emacs-25 branch), transient-mark-mode is on by default and I have
customized the delete-selection-mode to be t (default was nil).