stterm doesn't understand all codes that xterm does

* lisp/term/st.el (xterm-st-extra-capabilities): New user option
(bug#50119).
(terminal-init-st): Use it to avoid a two-second timeout.

1 files changed, 12 insertions, 1 deletions

diff --git a/lisp/term/st.el b/lisp/term/st.el
index 9a1c0646f89..e1db450b3e7 100644
--- a/lisp/term/st.el
+++ b/lisp/term/st.el
@@ -11,9 +11,20 @@
 
 (require 'term/xterm)
 
+(defcustom xterm-st-extra-capabilities '( modifyOtherKeys getSelection
+                                          setSelection)
+  "Extra capabilities supported under \"stterm\".
+Some features of screen depend on the terminal emulator in which
+it runs, which can change when the screen session is moved to another tty."
+  :version "28.1"
+  :type xterm--extra-capabilities-type
+  :group 'xterm)
+
 (defun terminal-init-st ()
   "Terminal initialization function for st."
-  (tty-run-terminal-initialization (selected-frame) "xterm"))
+  ;; Using `check' leads to a two-second timeout.
+  (let ((xterm-extra-capabilities xterm-st-extra-capabilities))
+    (tty-run-terminal-initialization (selected-frame) "xterm")))
 
 (provide 'term/st)