bug#45617: <query-replace> loses the edit region. Works in 23.3, broke in 26.3

[Bob Floyd]

I tried, for the first time, 'emacs -Q', repeatedly doing 

1. select region by dragging mouse-1, sometimes top-to-bottom, sometimes
bottom-to-top
2. start <query-replace>
3. double click mouse-1 on some text on a top line, always the same text
4. yank that text to the command example:
    Query replace in region _xxx with:
5. with keyboard enter
    Query replace in region _xxx with: _iSmbl
6. then keyboard <enter> to start.

It was doing the expected, correct, query replace, for the first, oh, maybe
six times, then got into the broken state and when I repeat the above
sequence it behaves as if there was no region selected and no replacements
are offered (Replaced 0 occurences).

It seems like something was not restored correctly. I cannot say I precisely
followed the above steps for the first times when it was working - I wanted
to vary the sequence a bit (sometimes entering from the keyboard, sometimes
selecting text from a lower line in the selection) to see if I could break
it. I cannot be more specific about exactly which sequence broke it, only
that now, when it's broken, it consistently does not work!

  



-----Original Message-----
From: Juri Linkov [mailto:juri@linkov.net] 
Sent: Monday, January 25, 2021 9:07 AM
To: Bob Floyd
Cc: 'Eli Zaretskii'; 45617@debbugs.gnu.org
Subject: Re: bug#45617: <query-replace> loses the edit region. Works in
23.3, broke in 26.3

> I'm embarrassed to include my .emacs file - it's an accumulation over
> time of a lot of stuff from unix and windows not cleaned up. Here it
> is: Maybe something in it causing the issue/ maybe not.

This means you don't see the problem when you don't load your .emacs file?
So when you start with 'emacs -Q' there is no problem?