A bug was filed against Emacs saying that Emacs didn't properly supported the italics in Screen.  See

  https://debbugs.gnu.org/cgi/bugreport.cgi?bug=65029

Investigation reveals that infocmp doesn't show any sitm and ritm capabilities when TERM is set to "screen".  That is so even after installing the latest version of Screen from your repository's master branch.  This is why Emacs doesn't recognize the support of italics under Screen.

If the current development code of Screen does implement support for italics, would you please answer the following questions:

  . Does Screen support sitm and ritm capabilities in that development version?

  . When installing the development version of Screen which supports italics, should the Terminfo database be updated in some way, to inform Emacs and other programs about this support?

Thanks in advance.

> Strange, for me master branch works with italics in xterm (vim user here)

You are right. After taking a careful look, it's a tricky issue. Emacs does indeed have italics support after switching to screen master. However, it is broken. What should be italics, is displayed underlined. But some italics show up now e.g. in the menu bar. And outside Emacs, but still inside screen, xterm now displays italics correctly.

It would be great if a new release of screen could be made to get this feature on regular package managers. In the meantime, I will try to figure out what is wrong with Emacs.

I just tested master branch (rev 6931ba07ca1646df8dee85485f9867b23b34fcf1) using xterm (v383) and emacs (29.1). It did not work, italics showed up as underlined characters. Running emacs on the same setup but outside screen worked as expected.

This bug shows up with status fixed, but still affects the current release (Screen version 4.09.00 (GNU) 30-Jan-22) used together with mainstream terminals such as xterm or rxvt-unicode.

As other users have noted, this is a quite annoying issue as it makes it hard to use Emacs inside Screen. Lots of modern Emacs packages display a lot of colored and italics text, which due to this issue shows up with long broken underlines beneath.

Still doesn't work?

I have my custom terminfo entry xterm-256-italic (which does support italics) running in iTerm2 (macOS), which also support italics. And if I test with commands like below, then I do see italicized text in my terminal:

- echo `tput sitm`italics`tput ritm`
- printf "\e[3;mitalics\n\e[0m"

However, if I then run screen (screen --version reports Screen version 4.08.00 (GNU) 05-Feb-20), my $TERM sets to screen-256color, and the both commands mentioned above print the regular text, not italics.

And if I export TERM=xterm-256-italic inside screen, then

- printf "\e[3;mitalics\n\e[0m" prints regular text, and
- echo `tput sitm`italics`tput ritm` outputs standout text (which does confirm the original bug report, right?)

Would be grateful for an advice, thank you.

About, sorry.

I would like to have this feature too

Hi, screen does not support italics on terminals which support it, e.g. rxvt-unicode.  This is all the more disappointing as emacs trunk now supports italics on terminals which do so.


To reproduce start a terminal emulator which is able to display italics:

urxvt  -fn 'xft:liberation mono' -tn rxvt-unicode-256color

do

echo `tput sitm`italics`tput ritm` `tput smso`standout`tput rmso`

see italic font.

do

screen

do

echo `tput sitm`italics`tput ritm` `tput smso`standout`tput rmso`

again

see no italic fonts.


Expected result: should show italics.


Thanx for looking into this, Gregor