feat(ruff): add fallback 3rd party completion loader

Author: scop

completions/Makefile.am

@@ -375,6 +375,7 @@ bashcomp_DATA = 2to3 \
 		rrdtool \
 		rsync \
 		_rtcwake \
+		_ruff \
 		_runuser \
 		sbcl \
 		sbopkg \

completions/_ruff

@@ -0,0 +1,18 @@
+# 3rd party completion loader for commands emitting        -*- shell-script -*-
+# their completion using "$cmd generate-shell-completion bash".
+#
+# This serves as a fallback in case the completion is not installed otherwise.
+
+# shellcheck disable=SC2168 # "local" is ok, assume sourced by __load_completion
+local _comp__load_3rdparty_reset_shopt=$(shopt -po posix)
+set +o posix
+
+. <("$1" generate-shell-completion bash 2>/dev/null)
+
+$_comp__load_3rdparty_reset_shopt
+
+{
+    complete -p "$1" || complete -p "${1##*/}"
+} &>/dev/null
+
+# ex: filetype=sh

test/fallback/completions/Makefile.am

@@ -23,6 +23,7 @@ EXTRA_DIST = \
 	reptyr \
 	rfkill \
 	rtcwake \
+	ruff \
 	runuser \
 	slackpkg \
 	su \

test/fallback/completions/ruff

@@ -0,0 +1 @@
+../../../completions/_ruff