tmux: Emulate normal-mode y without selection

Try to mimic vim's normal and visual mode behaviour of `y`.

Set 'copy-command' for the copy-pipe commands to fall back to.

.config/tmux/tmux.conf

@@ -10,6 +10,9 @@ run-shell 'mkdir -p "${XDG_DATA_HOME:-$HOME/.local/share}/tmux"'
 # Better clipboard on mousedrag (https://unix.stackexchange.com/a/349020)
 # Disable xterm escape sequences for setting clipboard
 set -s set-clipboard off
+
+set -g copy-command 'xclip -selection clipboard'
+
 # Copy selection into primary selection (without aborting)
 bind -T copy-mode-vi MouseDragEnd1Pane send -X copy-pipe-no-clear "xclip -se p"
 
@@ -85,7 +88,17 @@ bind Escape copy-mode
 unbind -T copy-mode-vi v
 bind -T copy-mode-vi v send -X begin-selection
 # Yank into system clipboard
-bind -T copy-mode-vi y send -X copy-pipe "xclip -selection clipboard"
+# TODO: This breaks on repeatable movements (e.g. `y2e`)
+bind -T copy-mode-vi y \
+	if -F "#{selection_present}" {
+		send -X copy-pipe
+	} {
+		command-prompt -k -p (operator-pending) {
+			send -X begin-selection
+			send "%%"
+			send -X copy-pipe
+		}
+	}
 
 # Clear selection or cancel copy-mode when nothing is selected
 bind -T copy-mode-vi Escape \