Reimplement umount completion to not use gawk's gensub.

Gbp-Pq: Name umount-completion.patch

bash-completion/umount

@@ -1,3 +1,33 @@
+_umount_points_list()
+{
+	# List of characters to escape, shamelessly stolen from "scp" comp.
+	local escape_chars='[][(){}<>\",:;^&!$=?`|\\'\'' \t\f\n\r\v]'
+
+	# This is most odd, but we are adding artifically a space after the
+	# file name because, somehow, it enables proper escaping of dangerous
+	# characters, e.g. "|" -> "\|".  Without space, it is possible to get
+	# either 0 "|" or 2 "\\|" backslashes, but 1 does not work.  Also,
+	# sticking to sub() and gsub(), instead of gensub(), allows to be AWK
+	# implementation agnostic.
+	findmnt -lno TARGET | awk '{
+		if ($0 ~ "^"ENVIRON["HOME"]) {
+			homeless = $0
+			sub("^"ENVIRON["HOME"], "~", homeless)
+			gsub("'"$escape_chars"'", "\\\\&", homeless)
+			print homeless " "
+		}
+		if ($0 ~ "^"ENVIRON["PWD"]) {
+			reldir = $0
+			sub("^"ENVIRON["PWD"]"/?", "", reldir)
+			gsub("'"$escape_chars"'", "\\\\&", reldir)
+			print "./" reldir " "
+			print reldir " "
+		}
+		gsub("'"$escape_chars"'", "\\\\&")
+		print $0 " "
+	}'
+}
+
 _umount_module()
 {
 	local cur prev OPTS
@@ -48,28 +78,11 @@ _umount_module()
 			return 0
 			;;
 	esac
-
-	local oldifs=$IFS
-	IFS=$'\n'
-	COMPREPLY=( $( compgen -W "$(findmnt -lno TARGET | awk \
-		'{
-			if ($0 ~ ENVIRON["HOME"]) {
-				homeless = $0
-				homeless = gensub(ENVIRON["HOME"], "\\\\~", "g", homeless)
-				homeless = gensub(/(\s)/, "\\\\\\1", "g", homeless)
-				print homeless
-			}
-			if ($0 ~ ENVIRON["PWD"]) {
-				reldir = $0
-				reldir = gensub(ENVIRON["PWD"]"/", "", "g", reldir)
-				reldir = gensub(/(\s)/, "\\\\\\1", "g", reldir)
-				print "./" reldir
-				print reldir
-			}
-			gsub(/\s/, "\\\\&")
-			print $0
-		}'
-	)" -- "$cur" ) )
-	IFS=$oldifs
+	local IFS=$'\n'
+	COMPREPLY=( $( compgen -W '$( _umount_points_list )'  -- "$cur" ) )
 }
-complete -F _umount_module umount
+
+# counteract the artificial addition of " " in _gen_mount_points() by
+# disabling spaces automatically appended to the end of the file name
+# completion via "-o nospace".
+complete -F _umount_module -o nospace umount