handle debug traps with [[ specially (#157544)

* fix #154189

* add comment

src/vs/workbench/contrib/terminal/browser/media/shellIntegration-bash.sh

@@ -125,7 +125,14 @@ if [[ -n "${bash_preexec_imported:-}" ]]; then
 	precmd_functions+=(__vsc_prompt_cmd)
 	preexec_functions+=(__vsc_preexec_only)
 else
-	__vsc_dbg_trap="$(trap -p DEBUG | cut -d' ' -f3 | tr -d \')"
+	__vsc_dbg_trap="$(trap -p DEBUG)"
+	if [[ "$__vsc_db_trap" =~ .*\[\[.* ]]; then
+		#HACK - is there a better way to do this?
+		__vsc_dbg_trap=${__vsc_dbg_trap#'trap -- '*}
+		__vsc_dbg_trap=${__vsc_dbg_trap%'DEBUG'}
+	else
+		__vsc_dbg_trap="$(trap -p DEBUG | cut -d' ' -f3 | tr -d \')"
+	fi
 	if [[ -z "$__vsc_dbg_trap" ]]; then
 		__vsc_preexec_only() {
 			if [ "$__vsc_in_command_execution" = "0" ]; then