Bug#1067201: apt: Improved bash-completion for 'apt edit-sources'

[Peter Samuelson <peters@p12n.org>]

Package: apt
Version: 2.7.13
Severity: minor
Tags: patch

Attached are minor improvements to 'apt edit-sources' bash completion:

- Generate accurate '*.list' list of files, and omit '.list'
  suffixes. (I _would_ also list '*.sources', but current 'apt
  edit-sources' does not support this newer file format.)

- Quote filenames as needed

- Honor $APT_CONFIG by calling 'apt-config' instead of hardcoding
  /etc/apt/sources.list.d. (For efficiency, this is only in the
  'edit-sources' codepath.)

Quoting filenames seems like overkill, but _could_ matter for users
who maintain a separate non-default config under $HOME. (I do this in
order to make many additional 'deb-src' available, with corresponding
trusted keys, without encumbering the systemwide 'apt update'.)

Thanks,
Peter

--- a/completions/bash/apt
+++ b/completions/bash/apt
@@ -2,7 +2,6 @@
 
 _apt()
 {
-    local sourcesdir="/etc/apt/sources.list.d"
     local cur prev words cword
     _init_completion || return
 
@@ -211,8 +210,13 @@
                 return 0
                 ;;
             edit-sources)
-                COMPREPLY=( $( compgen -W '$( command ls $sourcesdir )' \
-                    -- "$cur" ) )
+		mapfile -t COMPREPLY < <(
+                    eval $(apt-config shell root Dir etcapt Dir::Etc sourcesdir Dir::Etc::sourceparts)
+                    [[ $etcapt == /* ]] || etcapt=$root/$etcapt
+                    [[ $sourcesdir == /* ]] || sourcesdir=$etcapt/$sourcesdir
+                    IFS='
+'                     compgen -W "$(shopt -s nullglob; basename -s.list "$sourcesdir"/*.list)" -- "$cur")
+                compopt -o filenames
                 return 0
                 ;;
             moo)