Bash completion: avoid 'compopt: command not found' errors on Mac OS

The shell builtin `compopt` is not available on the outdated bash
version 3.2.57 that ships with Mac OS.
It is used in Docker's bash completion to suppress trailing spaces
in advanced completions of hash map options, e.g. `--log-opt`.

If `compopt` is not available, the new behavior is to do nothing,
i.e. the user will have to delete the additional space.

Signed-off-by: Harald Albers <github@albersweb.de>

contrib/completion/bash/docker

@@ -212,6 +212,12 @@ __docker_to_extglob() {
 	echo "@($extglob)"
 }
 
+# suppress trailing whitespace
+__docker_nospace() {
+	# compopt is not available in ancient bash versions
+	type compopt &>/dev/null && compopt -o nospace
+}
+
 __docker_resolve_hostname() {
 	command -v host >/dev/null 2>&1 || return
 	COMPREPLY=( $(host 2>/dev/null "${cur%:}" | awk '/has address/ {print $4}') )
@@ -305,7 +311,7 @@ __docker_log_driver_options() {
 			;;
 	esac
 
-	compopt -o nospace
+	__docker_nospace
 }
 
 __docker_complete_log_driver_options() {
@@ -314,12 +320,12 @@ __docker_complete_log_driver_options() {
 	case "${words[$cword-2]}$prev=" in
 		*gelf-address=*)
 			COMPREPLY=( $( compgen -W "udp" -S "://" -- "${cur#=}" ) )
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		*syslog-address=*)
 			COMPREPLY=( $( compgen -W "tcp udp unix" -S "://" -- "${cur#=}" ) )
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		*syslog-facility=*)
@@ -492,7 +498,7 @@ _docker_cp() {
 					*)
 						__docker_containers_all
 						COMPREPLY=( $( compgen -W "${COMPREPLY[*]}" -S ':' ) )
-						compopt -o nospace
+						__docker_nospace
 						return
 						;;
 				esac
@@ -599,7 +605,7 @@ _docker_daemon() {
 					return
 					;;
 			esac
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		--log-level|-l)
@@ -662,7 +668,7 @@ _docker_events() {
 	case "$prev" in
 		--filter|-f)
 			COMPREPLY=( $( compgen -S = -W "container event image" -- "$cur" ) )
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		--since|--until)
@@ -777,7 +783,7 @@ _docker_images() {
 		--filter|-f)
 			COMPREPLY=( $( compgen -W "dangling=true label=" -- "$cur" ) )
 			if [ "$COMPREPLY" = "label=" ]; then
-				compopt -o nospace
+				__docker_nospace
 			fi
 			return
 			;;
@@ -975,7 +981,7 @@ _docker_ps() {
 			;;
 		--filter|-f)
 			COMPREPLY=( $( compgen -S = -W "ancestor exited id label name status" -- "$cur" ) )
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		--format|-n)
@@ -1207,18 +1213,18 @@ _docker_run() {
 					;;
 				'')
 					COMPREPLY=( $( compgen -W '/' -- "$cur" ) )
-					compopt -o nospace
+					__docker_nospace
 					;;
 				/*)
 					_filedir
-					compopt -o nospace
+					__docker_nospace
 					;;
 			esac
 			return
 			;;
 		--env|-e)
 			COMPREPLY=( $( compgen -e -- "$cur" ) )
-			compopt -o nospace
+			__docker_nospace
 			return
 			;;
 		--ipc)
@@ -1230,7 +1236,7 @@ _docker_run() {
 				*)
 					COMPREPLY=( $( compgen -W 'host container:' -- "$cur" ) )
 					if [ "$COMPREPLY" = "container:" ]; then
-						compopt -o nospace
+						__docker_nospace
 					fi
 					;;
 			esac
@@ -1243,7 +1249,7 @@ _docker_run() {
 				*)
 					__docker_containers_running
 					COMPREPLY=( $( compgen -W "${COMPREPLY[*]}" -S ':' ) )
-					compopt -o nospace
+					__docker_nospace
 					;;
 			esac
 			return
@@ -1265,7 +1271,7 @@ _docker_run() {
 				*)
 					COMPREPLY=( $( compgen -W "bridge none container: host" -- "$cur") )
 					if [ "${COMPREPLY[*]}" = "container:" ] ; then
-						compopt -o nospace
+						__docker_nospace
 					fi
 					;;
 			esac
@@ -1289,12 +1295,12 @@ _docker_run() {
 					local cur=${cur##*:}
 					COMPREPLY=( $( compgen -W "user: role: type: level: disable" -- "$cur") )
 					if [ "${COMPREPLY[*]}" != "disable" ] ; then
-						compopt -o nospace
+						__docker_nospace
 					fi
 					;;
 				*)
 					COMPREPLY=( $( compgen -W "label apparmor" -S ":" -- "$cur") )
-					compopt -o nospace
+					__docker_nospace
 					;;
 			esac
 			return