Subject: bug#6316: 24.0.50; unexpected region highlighting with disabled transient-mark-mode

From: Stephen Berman <[email-masked]>
Date: Mon, 31 May 2010 14:29:16 +0200

On Mon, 31 May 2010 09:30:34 +0200 Stephen Berman <[email-masked]> wrote:

> 1. emacs -Q
> 2. Type `M-x transient-mark-mode' to disable transient-mark-mode.
> 3. Select some text with the mouse.  To give a specific example for the
> sake of replication, type `C-h v transient-mark-mode RET', then in the
> *Help* buffer double click on the left parenthesis of "(only . OLDVAL)"
> to select the whole sexp, which thus gets highlighted.
> 4. Type `M-w', then put point at the start of the paragraph (in *Help*)
> beginning "Non-nil also enables highlighting".  Note that the region is
> not highlighted.
> 5. Paste "(only . OLDVAL)" into *scratch*, then double click on "OLDVAL",
> selecting and highlighting it.
> 6. Type `C-x o' to switch back to the *Help* buffer.
> => The region in *Help* between point and the left parenthesis of 
> "(only . OLDVAL)" is now highlighted.

I should have mentioned that selection with the mouse is not crucial;
the same unexpected highlighting occurs if selection is done via the
keyboard -- with the important qualification that in step 5, the
selection must be made by typing `C-SPC' twice to activate the mark,
then moving point to the end of "OLDVAL", so that it is highlighted.
(Mark activation is not necessary in step 3, in which case the selected
text would not be highlighted.)

Steve Berman