#
#
# patch "cmd.hh"
#  from [100b8bb08a126fb827acfd50e104897a4ffd8f97]
#    to [c160e0cdc96ccd368ee9aca2afac028408db400f]
# 
# patch "cmd_automate.cc"
#  from [fb7c5ee18a2e6ac46fb93ec49ef21bb1aa6bc81f]
#    to [d715e6735b4a263881a587911a343aa06b339706]
# 
# patch "commands.cc"
#  from [e21ce6ddd485cb7886581fe14be6d6b0616d3bf9]
#    to [bbd6a8914cb1fe58353d476e4f7802bc56971370]
# 
# patch "lua_hooks.cc"
#  from [57900637d5588e80197752a936229e320993202f]
#    to [e61801cae30ad803e68f8419729619159719137a]
# 
# patch "tests/invoke_toplevel_group/__driver__.lua"
#  from [659b589cfaba2f10b2256937403524a911270d43]
#    to [469031fb8da888896cfbd6e9e8d1e156fe78f082]
#
============================================================
--- cmd.hh	100b8bb08a126fb827acfd50e104897a4ffd8f97
+++ cmd.hh	c160e0cdc96ccd368ee9aca2afac028408db400f
@@ -34,6 +34,7 @@ namespace commands
     utf8 m_primary_name;
     names_set m_names;
     command * m_parent;
+    bool m_is_group;
     bool m_hidden;
     utf8 m_params;
     utf8 m_abstract;
@@ -53,6 +54,7 @@ namespace commands
     command(std::string const & primary_name,
             std::string const & other_names,
             command * parent,
+            bool is_group,
             bool hidden,
             std::string const & params,
             std::string const & abstract,
@@ -69,6 +71,7 @@ namespace commands
     names_set const & names(void) const;
     void add_alias(const utf8 &new_name);
     command * parent(void) const;
+    bool is_group(void) const;
     bool hidden(void) const;
     virtual std::string params(void) const;
     virtual std::string abstract(void) const;
@@ -186,8 +189,8 @@ namespace commands {                    
   class cmd_ ## C : public command                                   \
   {                                                                  \
   public:                                                            \
-    cmd_ ## C() : command(name, aliases, parent, hidden, params,     \
-                          abstract, desc, true,                      \
+    cmd_ ## C() : command(name, aliases, parent, false, hidden,      \
+                          params, abstract, desc, true,              \
                           options::options_type() | opts, true)      \
     {}                                                               \
     virtual void exec(app_state & app,                               \
@@ -211,8 +214,8 @@ void commands::cmd_ ## C::exec(app_state
   class cmd_ ## C : public command                                   \
   {                                                                  \
   public:                                                            \
-    cmd_ ## C() : command(name, aliases, parent, false, "", abstract,\
-                          desc, true,                                \
+    cmd_ ## C() : command(name, aliases, parent, true, false, "",    \
+                          abstract, desc, true,                      \
                           options::options_type(), cmpl)             \
     {}                                                               \
     virtual void exec(app_state & app,                               \
@@ -243,8 +246,8 @@ namespace commands {                    
   class cmd_ ## C : public command                                   \
   {                                                                  \
   public:                                                            \
-    cmd_ ## C() : command(name, aliases, parent, false, params,      \
-                          abstract, desc, false,                     \
+    cmd_ ## C() : command(name, aliases, parent, false, false,       \
+                          params, abstract, desc, false,             \
                           options::options_type() | opts, true)      \
     {}                                                               \
     virtual void exec(app_state & app,                               \
============================================================
--- cmd_automate.cc	fb7c5ee18a2e6ac46fb93ec49ef21bb1aa6bc81f
+++ cmd_automate.cc	d715e6735b4a263881a587911a343aa06b339706
@@ -38,7 +38,7 @@ namespace commands {
                      string const & abstract,
                      string const & desc,
                      options::options_type const & opts) :
-    command(name, "", CMD_REF(automate), false, params, abstract,
+    command(name, "", CMD_REF(automate), false, false, params, abstract,
             desc, true, opts, false)
   {
   }
============================================================
--- commands.cc	e21ce6ddd485cb7886581fe14be6d6b0616d3bf9
+++ commands.cc	bbd6a8914cb1fe58353d476e4f7802bc56971370
@@ -147,6 +147,7 @@ namespace commands {
   command::command(std::string const & primary_name,
                    std::string const & other_names,
                    command * parent,
+                   bool is_group,
                    bool hidden,
                    std::string const & params,
                    std::string const & abstract,
@@ -156,6 +157,7 @@ namespace commands {
                    bool _allow_completion)
     : m_primary_name(utf8(primary_name)),
       m_parent(parent),
+      m_is_group(is_group),
       m_hidden(hidden),
       m_params(utf8(params)),
       m_abstract(utf8(abstract)),
@@ -235,6 +237,12 @@ namespace commands {
   }
 
   bool
+  command::is_group(void) const
+  {
+    return m_is_group;
+  }
+
+  bool
   command::hidden(void) const
   {
     return m_hidden;
@@ -743,7 +751,8 @@ namespace commands
     string visibleid = join_words(vector< utf8 >(ident.begin() + 1,
                                                  ident.end()))();
 
-    N(!(!cmd->is_leaf() && cmd->parent() == CMD_REF(__root__)),
+    I(cmd->is_leaf() || cmd->is_group());
+    N(!(cmd->is_group() && cmd->parent() == CMD_REF(__root__)),
       F("command '%s' is invalid; it is a group") % join_words(ident));
 
     N(!(!cmd->is_leaf() && args.empty()),
============================================================
--- lua_hooks.cc	57900637d5588e80197752a936229e320993202f
+++ lua_hooks.cc	e61801cae30ad803e68f8419729619159719137a
@@ -974,7 +974,7 @@ namespace commands {
                    std::string const & desc,
                    lua_State *L_st,
                    std::string const & func_name) :
-         command(primary_name, "", CMD_REF(user), false, params,
+         command(primary_name, "", CMD_REF(user), false, false, params,
                  abstract, desc, true, options::options_type() | options::opts::none, true),
                  st(L_st), f_name(func_name)
     {
============================================================
--- tests/invoke_toplevel_group/__driver__.lua	659b589cfaba2f10b2256937403524a911270d43
+++ tests/invoke_toplevel_group/__driver__.lua	469031fb8da888896cfbd6e9e8d1e156fe78f082
@@ -6,6 +6,11 @@ check(string.find(output, "is invalid; i
 output = readfile("stderr")
 check(string.find(output, "is invalid; it is a group") ~= nil)
 
+-- Invoking an empty group fails with an appropriate error message.
+check(mtn("user"), 1, "", true)
+output = readfile("stderr")
+check(string.find(output, "is invalid; it is a group") ~= nil)
+
 -- Command completion does not work on groups.
 check(mtn("revie"), 1, "", true)
 output = readfile("stderr")