Update zsh completion for new help format

contrib/zsh_completion

@@ -4,14 +4,13 b''
 # it into your zsh function path (/usr/share/zsh/site-functions for
 # instance)
 #
-# Copyright (C) 2005 Steve Borho
+# Copyright (C) 2005-6 Steve Borho
 # Copyright (C) 2006-8 Brendan Cully <[e-mail]>
 #
 # This is free software; you can redistribute it and/or modify it under
 # the terms of the GNU General Public License as published by the Free
 # Software Foundation; either version 2 of the License, or (at your
 # option) any later version.
-#
 
 emulate -LR zsh
 setopt extendedglob
@@ -117,9 +116,27 b' typeset -A _hg_cmd_globals'
 _hg_get_commands() {
   typeset -ga _hg_cmd_list
   typeset -gA _hg_alias_list
-  local hline cmd cmdalias
-  _call_program help hg --verbose help | while read -A hline
+  local hline cmd cmdalias helpstate
+  local helpmode=$1
+
+  _call_program help hg --verbose help $helpmode 2>/dev/null | while read -A hline
   do
+    if [ "$hline" = "list of commands:" ]
+    then
+      helpstate="commands"
+      continue
+    elif [ "$hline" = "enabled extensions:" ]
+    then
+      helpstate="extensions"
+      continue
+    elif [ "$hline" = "additional help topics:" ]
+    then
+      helpstate="topics"
+      continue
+    fi
+
+    if [ "$helpstate" = commands ]
+    then
     cmd="$hline[1]"
     case $cmd in
       *:)
@@ -139,6 +156,14 b' typeset -A _hg_cmd_globals'
         done
       ;;
     esac
+    elif [ -z "$helpmode" -a "$helpstate" = extensions ]
+    then
+      cmd="$hline[1]"
+      if [ -n "$cmd" ]
+      then
+        _hg_get_commands $cmd
+      fi
+    fi
   done
 }