Bug#844325: xterm: display issue after sending zero-width characters to the terminal
Package: xterm
Version: 327-1
Severity: normal
The following command
for i in $(seq 2 $(tput cols)); do printf .; done; printf "\u00adP\n"
outputs a sequence of dots, then a soft hyphen, then the character "P"
on the right of the last column (only the left part of the character
is visible). In particular, when doing a "clear", one can still see
the left part of the character "P". The character "P" should have been
output either over the soft hyphen or at the first column of the next
line. Well, I don't know how zero-width characters should be handled,
but the behavior of xterm should be consistent.
There's the same issue with U+200F (RIGHT-TO-LEFT MARK) and probably
other zero-width characters:
for i in $(seq 2 $(tput cols)); do printf .; done; printf "\u200FP\n"
Note: with "xterm -k8", there is the same issue with
for i in $(seq 2 $(tput cols)); do printf .; done; printf "\255P\n"
as the byte \255 (= \xad) also corresponds to a soft hyphen.
-- System Information:
Debian Release: stretch/sid
APT prefers unstable-debug
APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.8.0-1-amd64 (SMP w/12 CPU cores)
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages xterm depends on:
ii libc6 2.24-5
ii libfontconfig1 2.11.0-6.7
ii libice6 2:1.0.9-1+b1
ii libtinfo5 6.0+20160917-1
ii libutempter0 1.1.6-3
ii libx11-6 2:1.6.3-1
ii libxaw7 2:1.0.13-1
ii libxft2 2.3.2-1
ii libxinerama1 2:1.1.3-1+b1
ii libxmu6 2:1.1.2-2
ii libxpm4 1:3.5.11-1+b1
ii libxt6 1:1.1.5-1
ii xbitmaps 1.1.1-2
Versions of packages xterm recommends:
ii x11-utils 7.7+3
Versions of packages xterm suggests:
pn xfonts-cyrillic <none>
-- no debconf information
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