Keep original behavior and unbind keys correctly

Because Tmux 2.4 doesn't forward bindings from the root prefix, we have
to fetch the original behavior using the list-keys command. That way, we
are able to forward it and to unbind it correctly.

Author: thalesmello

scripts/copycat_mode_bindings.sh

@@ -3,25 +3,37 @@
 CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 source "$CURRENT_DIR/helpers.sh"
+AWK_CMD='awk'
+if command_exists gawk; then
+	AWK_CMD='gawk'
+fi
 
 # Extends a keyboard key.
 # Benefits: tmux won't report errors and everything will work fine even if the
 # script is deleted.
 extend_key() {
 	local key="$1"
 	local script="$2"
+	local cmd
 
+	# 1. 'cmd' or 'key' is sent to tmux. This ensures the default key action is done.
+	# 2. Script is executed.
+	# 3. `true` command ensures an exit status 0 is returned. This ensures a
+	#	 user never gets an error msg - even if the script file from step 2 is
+	#	 deleted.
 	if tmux_is_at_least 2.4; then
+		# We fetch the current behavior of the 'key' mapping in
+		# variable 'cmd'
+		cmd=$(tmux list-keys -T copy-mode-$(tmux_copy_mode) | $AWK_CMD '$4 == "'$key'"' | $AWK_CMD '{ $1=""; $2=""; $3=""; $4=""; sub("  ", " "); print }')
+		# If 'cmd' is already a copycat command, we do nothing
+		if echo "$cmd" | grep -q copycat; then
+			return
+		fi
 		# We save the previous mapping to a file in order to be able to recover
 		# the previous mapping when we unbind
-		tmux list-keys -T copy-mode-$(tmux_copy_mode) | grep -F "$key" >> /tmp/copycat_$(whoami)_recover_keys
-		tmux bind-key -T copy-mode-$(tmux_copy_mode) "$key" run-shell "$script"
+		tmux list-keys -T copy-mode-$(tmux_copy_mode) | $AWK_CMD '$4 == "'$key'"' >> /tmp/copycat_$(whoami)_recover_keys
+		tmux bind-key -T copy-mode-$(tmux_copy_mode) "$key" run-shell "tmux $cmd; $script; true"
 	else
-		# 1. 'key' is sent to tmux. This ensures the default key action is done.
-		# 2. Script is executed.
-		# 3. `true` command ensures an exit status 0 is returned. This ensures a
-		#	 user never gets an error msg - even if the script file from step 2 is
-		#	 deleted.
 		tmux bind-key -n "$key" run-shell "tmux send-keys '$key'; $script; true"
 	fi
 }

scripts/copycat_mode_quit.sh

@@ -19,9 +19,9 @@ unbind_prev_next_bindings() {
 
 unbind_all_bindings() {
 	if tmux_is_at_least 2.4; then
-		while read key_cmd; do
+		grep -v copycat </tmp/copycat_$(whoami)_recover_keys | while read key_cmd; do
 			tmux $key_cmd
-		done < /tmp/copycat_$(whoami)_recover_keys
+		done < /dev/stdin
 		rm /tmp/copycat_$(whoami)_recover_keys
 	else
 		unbind_cancel_bindings