feat(_comp_compgen): support -U var to unlocal var

Author: akinomyoga

bash_completion

@@ -422,6 +422,21 @@ _comp_compgen__error_fallback()
 #           The array name should not start with an underscores "_", which is
 #           internally used.  The array name should not be either "IFS" or
 #           "OPT{IND,ARG,ERR}".
+#   -U var  Unlocal VAR before performing the assignments.  This option can be
+#           specified multiple times to register multiple variables.  This
+#           option is supposed to be used by a parent generator (G1) when G1
+#           defines a local variable name that does not start with `_`.  In
+#           such a case, when a conflicting `-v VAR` is specified to the
+#           generator call, the assignments to VAR fail to propagate outside
+#           G1.  To avoid such a situation, `-U VAR` provides a mechanism to
+#           unlocal VAR before accessing variables specified to G1 by `-v`.  If
+#           this is a builtin compgen call (i.e., _comp_compgen [options] --
+#           options), the specified variables are unlocalized after calling the
+#           builtin `compgen` and before assigning results to the array
+#           specified by `-v`.  If this is a child generator call (i.e.,
+#           _comp_compgen [options] G2 ...), the specified variables are
+#           unlocalized before calling the generator function
+#           `_comp_compgen_G2`.
 #   -c cur  Set a word used as a prefix to filter the completions.  The default
 #           is ${cur-}.
 #   -R      The same as -c ''.  Use raw outputs without filtering.
@@ -512,14 +527,15 @@ _comp_compgen()
     local _dir=""
     local _ifs=$' \t\n' _has_ifs=""
     local _icmd="" _xcmd=""
+    local -a _upvars=()
 
     local _old_nocasematch=""
     if shopt -q nocasematch; then
         _old_nocasematch=set
         shopt -u nocasematch
     fi
     local OPTIND=1 OPTARG="" OPTERR=0 _opt
-    while getopts ':av:Rc:C:lF:i:x:' _opt "$@"; do
+    while getopts ':av:U:Rc:C:lF:i:x:' _opt "$@"; do
         case $_opt in
             a) _append=set ;;
             v)
@@ -529,6 +545,16 @@ _comp_compgen()
                 fi
                 _var=$OPTARG
                 ;;
+            U)
+                if [[ $OPTARG == @(*[^_a-zA-Z0-9]*|[0-9]*|'') ]]; then
+                    printf 'bash_completion: %s: -U: invalid variable name `%s'\''\n' "$FUNCNAME" "$OPTARG" >&2
+                    return 2
+                elif [[ $OPTARG == @(_*|IFS|OPTIND|OPTARG|OPTERR) ]]; then
+                    printf 'bash_completion: %s: -U: unnecessary to mark `%s'\'' as upvar\n' "$FUNCNAME" "$OPTARG" >&2
+                    return 2
+                fi
+                _upvars+=("$OPTARG")
+                ;;
             c) _cur=$OPTARG ;;
             R) _cur="" ;;
             C)
@@ -588,6 +614,8 @@ _comp_compgen()
             return 2
         fi
 
+        ((${#_upvars[@]})) && _comp_unlocal "${_upvars[@]}"
+
         if [[ $_dir ]]; then
             local _original_pwd=$PWD
             local PWD=${PWD-} OLDPWD=${OLDPWD-}
@@ -653,6 +681,7 @@ _comp_compgen()
         return
     }
 
+    ((${#_upvars[@]})) && _comp_unlocal "${_upvars[@]}"
     _comp_split -l ${_append:+-a} "$_var" "$_result"
 }
 
@@ -1078,9 +1107,7 @@ _comp_compgen_filedir()
     # Note: bash < 4.4 has a bug that all the elements are connected with
     # ${v+"${a[@]}"} when IFS does not contain whitespace.
     local IFS=$' \t\n'
-    local -a _tmp=(${toks[@]+"${toks[@]}"})
-    _comp_unlocal toks
-    _comp_compgen_set ${_tmp[@]+"${_tmp[@]}"}
+    _comp_compgen -U toks set ${toks[@]+"${toks[@]}"}
 } # _comp_compgen_filedir()
 
 # This function splits $cur=--foo=bar into $prev=--foo, $cur=bar, making it
@@ -1535,11 +1562,8 @@ _comp_compgen_usage()
 _comp_compgen_signals()
 {
     local -a sigs
-    if _comp_compgen -v sigs -c "SIG${cur#"${1-}"}" -- -P "${1-}" -A signal; then
-        local -a _sigs=("${sigs[@]/#${1-}SIG/${1-}}")
-        _comp_unlocal sigs
-        _comp_compgen_set "${_sigs[@]}"
-    fi
+    _comp_compgen -v sigs -c "SIG${cur#"${1-}"}" -- -P "${1-}" -A signal &&
+        _comp_compgen -U sigs set "${sigs[@]/#${1-}SIG/${1-}}"
 }
 
 # This function completes on known mac addresses
@@ -1578,9 +1602,7 @@ _comp_compgen_mac_addresses()
     _comp_compgen -av addresses split -- "$(command sed -ne \
         "s/^[[:space:]]*\($_re\)[[:space:]].*/\1/p" /etc/ethers 2>/dev/null)"
 
-    local -a _addresses=("${addresses[@]}")
-    _comp_unlocal addresses
-    _comp_compgen_ltrim_colon "${_addresses[@]}"
+    _comp_compgen -U ltrim_colon "${addresses[@]}"
 }
 
 # This function completes on configured network interfaces
@@ -1589,32 +1611,29 @@ _comp_compgen_mac_addresses()
 _comp_compgen_configured_interfaces()
 {
     local -a files
-    local _list
     if [[ -f /etc/debian_version ]]; then
         # Debian system
         _comp_expand_glob files '/etc/network/interfaces /etc/network/interfaces.d/*'
         ((${#files[@]})) || return 0
-        _list=$(command sed -ne \
-            's|^iface \([^ ]\{1,\}\).*$|\1|p' "${files[@]}" 2>/dev/null)
+        _comp_compgen -U files split -- "$(command sed -ne \
+            's|^iface \([^ ]\{1,\}\).*$|\1|p' "${files[@]}" 2>/dev/null)"
     elif [[ -f /etc/SuSE-release ]]; then
         # SuSE system
         _comp_expand_glob files '/etc/sysconfig/network/ifcfg-*'
         ((${#files[@]})) || return 0
-        _list=$(printf '%s\n' "${files[@]}" |
-            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')
+        _comp_compgen -U files split -- "$(printf '%s\n' "${files[@]}" |
+            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     elif [[ -f /etc/pld-release ]]; then
         # PLD Linux
-        _list=$(command ls -B /etc/sysconfig/interfaces |
-            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')
+        _comp_compgen -U files split -- "$(command ls -B /etc/sysconfig/interfaces |
+            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     else
         # Assume Red Hat
         _comp_expand_glob files '/etc/sysconfig/network-scripts/ifcfg-*'
         ((${#files[@]})) || return 0
-        _list=$(printf '%s\n' "${files[@]}" |
-            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')
+        _comp_compgen -U files split -- "$(printf '%s\n' "${files[@]}" |
+            command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     fi
-    _comp_unlocal files
-    _comp_compgen_split -- "$_list"
 }
 
 # Local IP addresses.
@@ -1642,12 +1661,10 @@ _comp_compgen_ip_addresses()
             "s|.*inet${_n}[[:space:]]\{1,\}\([^[:space:]/]*\).*|\1|p")" ||
         return
 
-    local -a _addrs=("${addrs[@]}")
-    _comp_unlocal addrs
     if [[ ! $_n ]]; then
-        _comp_compgen_set "${_addrs[@]}"
+        _comp_compgen -U addrs set "${addrs[@]}"
     else
-        _comp_compgen_ltrim_colon "${_addrs[@]}"
+        _comp_compgen -U addrs ltrim_colon "${addrs[@]}"
     fi
 }
 
@@ -1677,11 +1694,8 @@ _comp_compgen_available_interfaces()
             ifconfig -a || ip -c=never link show || ip link show
         fi
     } 2>/dev/null | awk \
-        '/^[^ \t]/ { if ($1 ~ /^[0-9]+:/) { print $2 } else { print $1 } }')" ||
-        return
-    local -a _generated=("${generated[@]/%[[:punct:]]/}")
-    _comp_unlocal generated
-    _comp_compgen_set "${_generated[@]}"
+        '/^[^ \t]/ { if ($1 ~ /^[0-9]+:/) { print $2 } else { print $1 } }')" &&
+        _comp_compgen -U set "${generated[@]}"
 }
 
 # Echo number of CPUs, falling back to 1 on failure.
@@ -1845,11 +1859,8 @@ else
                 done
             fi
         fi
-        if ((${#procs[@]})); then
-            local -a _procs=("${procs[@]}")
-            _comp_unlocal procs
-            _comp_compgen -- -X "<defunct>" -W '"${_procs[@]}"'
-        fi
+        ((${#procs[@]})) &&
+            _comp_compgen -U procs -- -X "<defunct>" -W '"${procs[@]}"'
     }
 fi
 
@@ -1897,9 +1908,7 @@ _comp_compgen_xinetd_services()
         local -a svcs
         _comp_expand_glob svcs '$_xinetddir/!($_comp_backup_glob)'
         if ((${#svcs[@]})); then
-            local _svcs=("${svcs[@]}")
-            _comp_unlocal svcs
-            _comp_compgen -- -W '"${_svcs[@]#$_xinetddir/}"'
+            _comp_compgen -U svcs -- -W '"${svcs[@]#$_xinetddir/}"'
         fi
     fi
 }