PATCH: _iconv: support libiconv version of iconv

["Jun T." <takimoto-j@xxxxxxxxxxxxxxxxx>]

There are two variants of GNU iconv, one from glibc and the other from
libiconv, and the lists of encodings output by 'iconv --list' are in
different formats; one encoding per line in the former, while in the latter
all the equivalent encodings (aliases) are in a single line (separated by
spaces). 
Most (all?) of Linuxes use glibc version, but Mac OS X uses libiconv.

The patch below is to add support for the libiconv version.
I also added '//IGNORE' as a possible suffix to encoding
(and offer suffixes only for -t/--to-code and not for -f/--from-code).



diff --git a/Completion/Unix/Command/_iconv b/Completion/Unix/Command/_iconv
index 190ed5f..82c2d32 100644
--- a/Completion/Unix/Command/_iconv
+++ b/Completion/Unix/Command/_iconv
@@ -1,37 +1,58 @@
 #compdef iconv
 
 local expl curcontext="$curcontext" state line ret=1
-local LOCPATH="${LOCPATH:-/usr/lib/nls/loc}"
-local -U codeset
-
-if _pick_variant gnu='(GNU|EGLIBC)' unix --version; then
-
-  local exargs="--list -? --help --usage --version -V"
-  _arguments -C -S -s \
-    "(-f --from-code $exargs)"{-f+,--from-code=}'[specify code set of input file]:code set:->codeset' \
-    "(-t --to-code $exargs)"{-t+,--to-code=}'[specify code set for output]:code set:->codeset' \
-    '(- 1 -l --list)'{-l,--list}'[list all character code sets]' \
-    "($exargs)-c[omit invalid characters from output]" \
-    "(-o --output $exargs)"{-o+,--output=}'[specify output file]:output file:_files' \
-    "(-s --silent --verbose $exargs)"{-s,--silent}'[suppress warnings]' \
-    "(-s --silent $exargs)--verbose[print progress information]" \
-    '(-)'{-\?,--help}'[display help information]' \
-    '(-)--usage[display a short usage message]' \
-    '(-)'{-V,--version}'[print program version]' \
-    '1:input file:_files' && return 0
 
-  if [[ $state = codeset ]]; then
-    if compset -P '*[^/]/'; then
-      _wanted option expl option compadd "$@" /TRANSLIT && ret=0
+if _pick_variant libiconv='GNU*libiconv' glibc='(GNU*libc|EGLIBC)' unix --version; then
+  local -a args
+  local exargs="-l --list -? --help --usage --version -V"
+
+  args=(
+    "(-f --from-code $exargs)"{-f+,--from-code=}'[specify code set of input file]:code set:->from_codeset'
+    "(-t --to-code $exargs)"{-t+,--to-code=}'[specify code set for output]:code set:->to_codeset'
+    '(- 1 -l --list)'{-l,--list}'[list all character code sets]'
+    "($exargs)-c[omit invalid characters from output]"
+    "(-s --silent --verbose $exargs)"{-s,--silent}'[suppress warnings]'
+    '(-)'{-\?,--help}'[display help information]'
+    '(-)--usage[display a short usage message]'
+    '(-)'{-V,--version}'[print program version]'
+    '1:input file:_files' 
+  )
+
+  case $_cmd_variant[$service] in
+    (libiconv)
+      args=( ${(R)args:#(|\*)(|\(*\))-[V\?]*} )  # remove -V and -?
+      args+=(
+       '--byte-subst=[format for unconvertible bytes]:format string:'
+       '--widechar-subst=[format for unconvertible wide chars]:format string:'
+       '--unicode-subst=[format for unconvertible Unicode chars]:format string:'
+      )
+      ;;
+    (glibc)
+      args+=( 
+        "(-o --output $exargs)"{-o+,--output=}'[specify output file]:output file:_files'
+        "(-s --silent $exargs)--verbose[print progress information]"
+      )
+      ;;
+  esac
+
+  _arguments -C -S -s : $args && return 0
+
+  if [[ $state = *_codeset ]]; then
+    # suffix is meaningfull only for output encoding
+    if [[ $state = to_codeset ]] && compset -P '*[^/]/'; then
+      _wanted suffix expl suffix compadd "$@" /TRANSLIT /IGNORE && ret=0
     else
       _wanted codesets expl 'code set' compadd "$@" \
-	  -M 'm:{a-zA-Z}={A-Za-z} r:|-=* r:|=*' \
-	  ${${${(f)"$(_call_program codesets iconv --list)"}## #}%//} && ret=0
+        -M 'm:{a-zA-Z}={A-Za-z} r:|-=* r:|=*' \
+        ${$(_call_program codesets iconv --list)%//} && ret=0
     fi
   fi
 
   return ret
+
 else
+  local LOCPATH="${LOCPATH:-/usr/lib/nls/loc}"
+  local -U codeset
 
   _arguments -C \
     '-f[specify code set of input file]:code set:->codeset' \