fix: use _comp_compgen with API changes

bash_completion

@@ -397,6 +397,23 @@ _comp_split()
     ((_new_size > _old_size))
 }
 
+# Helper function for _comp_compgen
+# @var[in] $?
+# @var[in] _var
+# @var[in] _append
+# @return original $?
+_comp_compgen__error_fallback()
+{
+    local _status=$?
+    if [[ $_append ]]; then
+        # make sure existence of variable
+        eval -- "$_var+=()"
+    else
+        eval -- "$_var=()"
+    fi
+    return "$_status"
+}
+
 # Provide a common interface to generate completion candidates in COMPREPLY or
 # in a specified array.
 # OPTIONS
@@ -414,6 +431,7 @@ _comp_split()
 #   -c cur  Set a word used as a prefix to filter the completions.  The default
 #           is ${cur-}.
 #   -R      The same as -c ''.  Use raw outputs without filtering.
+#   -C dir  Evaluate compgen/generator in the specified directory.
 # @var[in,opt] cur  Used as the default value of a prefix to filter the
 #   completions.
 #
@@ -437,10 +455,10 @@ _comp_split()
 #   as `-v arr` as a part of the `_comp_compgen` options.
 #
 # Usage #2: _comp_compgen [-alR|-v arr|-c cur] name args...
-# Call `_comp_compgen_NAME ARGS...` with the specified options.  This provides
-# a common interface to call the functions `_comp_compgen_NAME`, which produce
-# completion candidates, with custom options [-alR|-v arr|-c cur].  The option
-# `-F sep` is not used with this usage.
+# Call the generator `_comp_compgen_NAME ARGS...` with the specified options.
+# This provides a common interface to call the functions `_comp_compgen_NAME`,
+# which produce completion candidates, with custom options [-alR|-v arr|-c
+# cur].  The option `-F sep` is not used with this usage.
 # @param $1... name args  Calls the function _comp_compgen_NAME with the
 #   specified ARGS (if $1 does not start with a hyphen `-`).  The options
 #   [-alR|-v arr|-c cur] are inherited by the child calls of `_comp_compgen`
@@ -484,10 +502,15 @@ _comp_compgen()
     local _append=${_comp_compgen__append-}
     local _var=${_comp_compgen__var-COMPREPLY}
     local _cur=${_comp_compgen__cur-${cur-}}
-    local _ifs=$' \t\n'
+    local _ifs=$' \t\n' _dir=""
 
+    local _old_nocasematch=""
+    if shopt -q nocasematch; then
+        _old_nocasematch=set
+        shopt -u nocasematch
+    fi
     local OPTIND=1 OPTARG="" OPTERR=0 _opt
-    while getopts ':alF:v:Rc:' _opt "$@"; do
+    while getopts ':alF:v:Rc:C:' _opt "$@"; do
         case $_opt in
             a) _append=set ;;
             v)
@@ -501,12 +524,20 @@ _comp_compgen()
             F) _ifs=$OPTARG ;;
             c) _cur=$OPTARG ;;
             R) _cur="" ;;
+            C)
+                if [[ ! $OPTARG ]]; then
+                    printf 'bash_completion: %s: -C: invalid directory name `%s'\''.\n' "$FUNCNAME" "$OPTARG" >&2
+                    return 2
+                fi
+                _dir=$OPTARG
+                ;;
             *)
                 printf 'bash_completion: %s: usage error\n' "$FUNCNAME" >&2
                 return 2
                 ;;
         esac
     done
+    [[ $_old_nocasematch ]] && shopt -s nocasematch
     shift "$((OPTIND - 1))"
     if (($# == 0)); then
         printf 'bash_completion: %s: unexpected number of arguments.\n' "$FUNCNAME" >&2
@@ -521,14 +552,35 @@ _comp_compgen()
             return 2
         fi
 
+        if [[ $_dir ]]; then
+            local _original_pwd=$PWD
+            local PWD=${PWD-} OLDPWD=${OLDPWD-}
+            # Note: We also redirect stdout because `cd` may output the target
+            # directory to stdout when CDPATH is set.
+            command cd -- "$_dir" &>/dev/null ||
+                {
+                    _comp_compgen__error_fallback
+                    return
+                }
+        fi
+
         local _comp_compgen__append=$_append
         local _comp_compgen__var=$_var
         local _comp_compgen__cur=$_cur cur=$_cur
         # Note: we use $1 as a part of a function name, and we use $2... as
         # arguments to the function if any.
         # shellcheck disable=SC2145
         _comp_compgen_"$@"
-        return
+        local _status=$?
+
+        # Go back to the original directory.
+        # Note: Failure of this line results in the change of the current
+        # directory visible to the user.  We intentionally do not redirect
+        # stderr so that the error message appear in the terminal.
+        # shellcheck disable=SC2164
+        [[ $_dir ]] && command cd -- "$_original_pwd"
+
+        return "$_status"
     fi
 
     # usage: _comp_compgen [options] -- [compgen_options]
@@ -550,16 +602,15 @@ _comp_compgen()
 
     local _result
     _result=$(
+        if [[ $_dir ]]; then
+            # Note: We also redirect stdout because `cd` may output the target
+            # directory to stdout when CDPATH is set.
+            command cd -- "$_dir" &>/dev/null || return
+        fi
         IFS=$_ifs compgen "$@" ${_cur:+-- "$_cur"}
     ) || {
-        local _status=$?
-        if [[ $_append ]]; then
-            # make sure existence of variable
-            eval -- "$_var+=()"
-        else
-            eval -- "$_var=()"
-        fi
-        return "$_status"
+        _comp_compgen__error_fallback
+        return
     }
 
     _comp_split -l ${_append:+-a} "$_var" "$_result"
@@ -1508,13 +1559,19 @@ _available_interfaces()
 }
 
 # Echo number of CPUs, falling back to 1 on failure.
-# TODO:API: rename per conventions, rework to use vars rather than outputting
-_ncpus()
+# @var[out] ret
+# @return 0 if it successfully obtained the number of CPUs, or otherwise 1
+# @since 2.12
+_comp_get_ncpus()
 {
     local var=NPROCESSORS_ONLN
     [[ $OSTYPE == *@(linux|msys|cygwin)* ]] && var=_$var
-    local n=$(getconf $var 2>/dev/null)
-    printf %s "${n:-1}"
+    if ret=$(getconf $var 2>/dev/null) && ((ret >= 1)); then
+        return 0
+    else
+        ret=1
+        return 1
+    fi
 }
 
 # Perform tilde (~) completion

bash_completion.d/000_bash_completion_compat.bash

@@ -335,4 +335,12 @@ _parse_usage()
     return 0
 }
 
+# @deprecated 2.12 Use `_comp_get_ncpus`.
+_ncpus()
+{
+    local ret
+    _comp_get_ncpus
+    printf %s "$ret"
+}
+
 # ex: filetype=sh

completions/2to3

@@ -15,7 +15,9 @@ _comp_cmd_2to3()
             return
             ;;
         -j | --processes)
-            COMPREPLY=($(compgen -W "{1..$(_ncpus)}" -- "$cur"))
+            local ret
+            _comp_get_ncpus
+            _comp_compgen -- -W "{1..$ret}"
             return
             ;;
         -o | --output-dir)

completions/_modules

@@ -21,30 +21,26 @@
 # being sourced before it and thus before the `module' alias has been defined.
 [[ -f /etc/profile.d/modules.sh ]] || return 1
 
-# TODO:API: rename per conventions, rework to use vars rather than outputting
-_module_list()
+_comp_cmd_module__compgen_list()
 {
     local modules="$(command sed 's/:/ /g' <<<"$LOADEDMODULES" | sort)"
-    compgen -W "$modules" -- "$1"
+    _comp_compgen -- -W "$modules"
 }
 
-# TODO:API: rename per conventions, rework to use vars rather than outputting
-_module_path()
+_comp_cmd_module__compgen_path()
 {
     local modules="$(command sed 's/:/ /g' <<<"$MODULEPATH" | sort)"
-    compgen -W "$modules" -- "$1"
+    _comp_compgen -- -W "$modules"
 }
 
-# TODO:API: rename per conventions, rework to use vars rather than outputting
-_module_avail()
+_comp_cmd_module__compgen_avail()
 {
     local modules="$(
         module avail 2>&1 |
             command grep -E -v '^(-|$)' |
             xargs printf '%s\n' | command sed -e 's/(default)//g' | sort
     )"
-
-    compgen -W "$modules" -- "$1"
+    _comp_compgen -- -W "$modules"
 }
 
 # A completion function for the module alias
@@ -65,19 +61,23 @@ _comp_cmd_module()
     elif ((cword == 2)); then
         case $prev in
             add | display | help | load | show | whatis)
-                COMPREPLY=($(_module_avail "$cur"))
+                # TODO:API: use generator call?
+                _comp_cmd_module__compgen_avail
                 ;;
             rm | switch | swap | unload | update)
-                COMPREPLY=($(_module_list "$cur"))
+                # TODO:API: use generator call?
+                _comp_cmd_module__compgen_list
                 ;;
             unuse)
-                COMPREPLY=($(_module_path "$cur"))
+                # TODO:API: use generator call?
+                _comp_cmd_module__compgen_path
                 ;;
         esac
     elif ((cword == 3)); then
         case ${words[1]} in
             swap | switch)
-                COMPREPLY=($(_module_avail "$cur"))
+                # TODO:API: use generator call?
+                _comp_cmd_module__compgen_avail
                 ;;
         esac
     fi

completions/_mount.linux

@@ -37,17 +37,11 @@ _comp_cmd_mount()
             return
             ;;
         -L)
-            COMPREPLY=($(
-                command cd "/dev/disk/by-label/" 2>/dev/null || return
-                compgen -f -- "$cur"
-            ))
+            _comp_compgen -C "/dev/disk/by-label/" -- -f
             return
             ;;
         -U)
-            COMPREPLY=($(
-                command cd "/dev/disk/by-uuid/" 2>/dev/null || return
-                compgen -f -- "$cur"
-            ))
+            _comp_compgen -C "/dev/disk/by-uuid/" -- -f
             return
             ;;
         -O | --test-opts)

completions/_slackpkg

@@ -65,22 +65,16 @@ _comp_cmd_slackpkg()
             ;;
         install-template | remove-template)
             if [[ -e $confdir/templates ]]; then
-                COMPREPLY=($(
-                    command cd -- "$confdir/templates"
-                    compgen -f -X "!*.template" -- "$cur"
-                ))
-                COMPREPLY=(${COMPREPLY[@]%.template})
+                _comp_compgen -C "$confdir/templates" -- -f -X \
+                    "!?*.template" && COMPREPLY=("${COMPREPLY[@]%.template}")
             fi
             return
             ;;
         remove)
             _comp_compgen_filedir
             _comp_compgen -a -- -W 'a ap d e f k kde kdei l n t tcl x xap xfce
                 y'
-            COMPREPLY+=($(
-                command cd /var/log/packages
-                compgen -f -- "$cur"
-            ))
+            _comp_compgen -aC /var/log/packages -- -f
             return
             ;;
         install | reinstall | upgrade | blacklist | download)

completions/_umount.linux

@@ -81,9 +81,8 @@ _comp_cmd_umount__linux_fstab()
             local i
             for i in ${!COMPREPLY[*]}; do
                 [[ ${COMPREPLY[i]} == "$realcur"* ]] &&
-                    COMPREPLY+=($(command cd -- "$dircur" 2>/dev/null &&
-                        compgen -f -d -P "$dircur" \
-                            -X "!${COMPREPLY[i]##"$dirrealcur"}" -- "$basecur"))
+                    _comp_compgen -aC "$dircur" -c "$basecur" -- \
+                        -f -d -P "$dircur" -X "!${COMPREPLY[i]##"$dirrealcur"}"
             done
         fi
     fi