Control: forwarded -1 https://savannah.gnu.org/bugs/?43145
Control: retitle -1 screen: corrupt display due to the U+061C character (ARABIC
LETTER MARK) or similar
Hi,
Thanks for these additional details and especially the easy
reproducer!
Vincent Lefevre wrote:
> The issue can be reproduced in the following way without needing Mutt:
>
> In a 80-column xterm, execute "screen bash", then
>
> for i in `seq 60` ; do printf 'a\u061c\u061c' ; done ; echo
That's not U+200F (RIGHT-TO-LEFT MARK) which you put in the subject
but U+061C ARABIC LETTER MARK. Updating the bug title accordingly.
> then reduce the terminal window by one line. This has the effect
> to duplicate the prompt and move the status line 2 lines above.
Indeed, can confirm.
Actually for me it already moves the status bar up one line without
resizing the terminal window — actually duplicating it except for the
time in the "upper" status bar which is no more updated.
The terminal window looks like this for me:
abe@c6:~ $ for i in `seq 60` ; do printf 'a\u061c\u061c' ; done ; echo
a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆a̍̎̆
abe@c6:~ $
_
where the a̍̎̆ above comes closest to the glyph shown to me by the uxterm
in which I started the screen session.
The glyph shown to me looks like an "a" with an "u" diacritical and on
top of that three vertical dots. (Tried to replace it above with "a̍̎"
which seems to come optically closest to the glyph I've been seeing.)
And that last underscore shows the position of the cursor shown to me.
I.e. the correct column, but one line lower than it should.
But even when I copy and paste it from the Screen session into a
text-mode Emacs (also inside a Screen session, but a different one),
it is shown me as "a" (looks like "a__" in Emacs to me), but is
actually still an "a" with 2x U+61C, ARABIC LETTER MARK behind it and
while moving through that string with Ctrl-F the cursor jumps (IMHO
correctly) once two positions forward, then one backward and again two
positions forward.
And the status line(s) looks like this:
c6: 0 bash | 0* bash | 2.34 2.83 3.13 | 23:41:41
c6: 0 bash | 0* bash | 4.55 3.25 3.05 | 23:52:32
I've configured this status line:
hardstatus alwayslastline "%H: %n %t | %w | %l | %c:%s"
And it seems even worse if you have (had) split windows inside the
screen session, i.e. by doing "C-a S" before executing the above
command: the layout is gone afterwards (except for some displayed
leftovers of the delimiter line) and only one is left window left —
the one in which I called that command.
P.S.: I've updated the upstream link from HTTP to HTTPS, i.e. I didn't
change which upstream bug is referenced, just the link's protocol.
Regards, Axel
--
,''`. | Axel Beckert <a...@debian.org>, https://people.debian.org/~abe/
: :' : | Debian Developer, ftp.ch.debian.org Admin
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