Subject: bug#24584: 25.1; Without fringe-mode, search highlighting on long lines breaks

From: Dima Kogan <[email-masked]>
Date: Sat, 01 Oct 2016 14:05:36 -0700

Hi.

I just found an unexpected interaction of fringe-mode and isearch. Let's
say you have the attached file (composed of random dictionary words on
two very long lines) called 'txt'. Then you

1. emacs -Q /tmp/txt
2. M-x toggle-truncate-lines
3. M-> (to go to end of buffer)
4. C-r threatened

As you type "threatened" letter by letter, you see the search jump to
the match, and the match is highlighted. This is correct. Now do

5. M-x fringe-mode no-fringes
6. M-> (to go to end of buffer)
7. C-r threatened

When you type "threatened" now, the behavior is correct through "th",
but when you hit "r", the buffer scrolls back to the beginning of the
line, and you can't see the match anymore.

I haven't done any debugging other than figuring out the exact thing
that makes it break: turning off fringe mode. If the exact cause isn't
obvious to somebody here, I'll debug it myself in a bit.