Re-enable extended keys

config/tmux.conf

@@ -60,15 +60,20 @@ bind C-y run 'tmux save-buffer - | $HOME/dotfiles/bin/clipboard-copy'
 # option, so only set it when the running tmux is new enough.
 if-shell "tmux -V | awk '{print $2}' | awk -F. '{if ($1*1000+$2 >= 3003) exit 0; else exit 1}'" 'set -g allow-passthrough on'
 
-# Deliberately OFF, do not re-enable: extended-keys makes tmux re-encode raw
-# control-equivalent bytes (Tab, CR, Backspace, Escape, and LF/Ctrl-J) into
-# CSI 27;<mod>;<key>~ sequences instead of passing the plain byte through,
-# any time it doesn't recognize the data as bracketed paste. Turning this on
-# previously mangled every LF byte -- both literal Ctrl+J keypresses and
-# every newline in pasted text -- into that unrecognized CSI sequence before
-# it reached the app in the pane, breaking Ctrl+J-as-newline and corrupting
-# multi-line pastes with literal escape-sequence garbage.
-set -s extended-keys off
+# Let tmux tell Shift+Enter apart from plain Enter and forward that
+# distinction inward, so Claude Code's Shift+Enter-inserts-newline shortcut
+# works. extended-keys/terminal-features need tmux >= 3.2. The terminal
+# name is matched with '*' rather than the commonly-suggested 'xterm*',
+# because a nested tmux's "terminal" is the outer tmux, which reports
+# itself using default-terminal above (screen-256color) -- 'xterm*' would
+# never match that, breaking the nested case this is meant to support.
+#
+# Investigated as a suspect for multi-line paste getting corrupted with
+# literal CSI 27;<mod>;<key>~ garbage in place of newlines (see Claude Code
+# issues #43169 and #30239) -- turning this off did not fix that paste
+# corruption, so it's an upstream Claude Code paste-tokenizer bug, not
+# something caused by this setting. Restored.
+if-shell "tmux -V | awk '{print $2}' | awk -F. '{if ($1*1000+$2 >= 3002) exit 0; else exit 1}'" 'set -s extended-keys on; set -as terminal-features "*:extkeys"'
 
 # Accept pane-originated OSC 52 clipboard-set attempts into a real tmux
 # buffer. Only on-vs-off matters here -- off would refuse to even look at