Merge from ruby_1_8. Add files that have not been added yet.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_7@16554 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

52 files changed, 822 insertions, 99 deletions

diff --git a/ext/tk/lib/multi-tk.rb b/ext/tk/lib/multi-tk.rb
index b3b9e69539..ec718678f0 100644
--- a/ext/tk/lib/multi-tk.rb
+++ b/ext/tk/lib/multi-tk.rb
@@ -2431,7 +2431,7 @@ class MultiTkIp
   def mainloop(check_root = true, restart_on_dead = true)
     raise SecurityError, "no permission to manipulate" unless self.manipulable?
 
-    unless WITH_RUBY_VM  ### Ruby 1.9 !!!!!!!!!!!
+    if WITH_RUBY_VM  ### Ruby 1.9 !!!!!!!!!!!
       return @interp_thread.value if @interp_thread
     end
 
diff --git a/ext/tk/lib/tk.rb b/ext/tk/lib/tk.rb
index e827d71ebc..c5d5b804d2 100644
--- a/ext/tk/lib/tk.rb
+++ b/ext/tk/lib/tk.rb
@@ -1298,7 +1298,7 @@ module TkCore
                              }) << ' %W')
 
   INTERP.add_tk_procs(TclTkLib::FINALIZE_PROC_NAME, '', 
-                      "bind all <#{WIDGET_DESTROY_HOOK}> {}")
+                      "catch { bind all <#{WIDGET_DESTROY_HOOK}> {} }")
 
   INTERP.add_tk_procs('rb_out', 'ns args', <<-'EOL')
     if [regexp {^::} $ns] {
@@ -3245,11 +3245,13 @@ module TkTreatFont
               next
             else
               fnt = hash_kv(fnt) if fnt.kind_of?(Hash)
-              begin
+              unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
                 tk_call(*(__config_cmd << "-#{optkey}" << fnt))
-              rescue => e
-                unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-                  fail e
+              else
+                begin
+                  tk_call(*(__config_cmd << "-#{optkey}" << fnt))
+                rescue
+                  # ignore
                 end
               end
             end
@@ -3305,11 +3307,13 @@ module TkTreatFont
         fobj = fontobj          # create a new TkFont object
       else
         ltn = hash_kv(ltn) if ltn.kind_of?(Hash)
-        begin
+        unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
           tk_call(*(__config_cmd << "-#{optkey}" << ltn))
-        rescue => e
-          unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-            fail e
+        else
+          begin
+            tk_call(*(__config_cmd << "-#{optkey}" << ltn))
+          rescue => e
+            # ignore
           end
         end
         next
@@ -3363,11 +3367,13 @@ module TkTreatFont
         fobj = fontobj          # create a new TkFont object
       else
         knj = hash_kv(knj) if knj.kind_of?(Hash)
-        begin
+        unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
           tk_call(*(__config_cmd << "-#{optkey}" << knj))
-        rescue => e
-          unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-            fail e
+        else
+          begin
+            tk_call(*(__config_cmd << "-#{optkey}" << knj))
+          rescue => e
+            # ignore
           end
         end
         next
@@ -3499,6 +3505,11 @@ module TkConfigMethod
   end
   private :__configinfo_struct
 
+  def __optkey_aliases
+    {}
+  end
+  private :__optkey_aliases
+
   def __numval_optkeys
     []
   end
@@ -3613,6 +3624,11 @@ module TkConfigMethod
       fail ArgumentError, "Invalid option `#{orig_slot.inspect}'"
     end
 
+    alias_name, real_name = __optkey_aliases.find{|k, v| k.to_s == slot}
+    if real_name
+      slot = real_name.to_s
+    end
+
     if ( method = _symbolkey2str(__val2ruby_optkeys())[slot] )
       optval = tk_call_without_enc(*(__cget_cmd << "-#{slot}"))
       begin
@@ -3687,14 +3703,35 @@ module TkConfigMethod
     unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
       __cget_core(slot)
     else
-      __cget_core(slot) rescue nil
+      begin
+        __cget_core(slot)
+      rescue => e
+        if current_configinfo.has_key?(slot.to_s)
+          # error on known option
+          fail e
+        else
+          # unknown option
+          nil
+        end
+      end
     end
   end
+  def cget_strict(slot)
+    # never use TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+    __cget_core(slot)
+  end
 
   def __configure_core(slot, value=None)
     if slot.kind_of? Hash
       slot = _symbolkey2str(slot)
 
+      __optkey_aliases.each{|alias_name, real_name|
+        alias_name = alias_name.to_s
+        if slot.has_key?(alias_name)
+          slot[real_name.to_s] = slot.delete(alias_name)
+        end
+      }
+
       __methodcall_optkeys.each{|key, method|
         value = slot.delete(key.to_s)
         self.__send__(method, value) if value
@@ -3731,6 +3768,11 @@ module TkConfigMethod
         fail ArgumentError, "Invalid option `#{orig_slot.inspect}'"
       end
 
+      alias_name, real_name = __optkey_aliases.find{|k, v| k.to_s == slot}
+      if real_name
+        slot = real_name.to_s
+      end
+
       if ( conf = __keyonly_optkeys.find{|k, v| k.to_s == slot} )
         defkey, undefkey = conf
         if value
@@ -3782,7 +3824,17 @@ module TkConfigMethod
           __configure_core(slot) unless slot.empty?
         end
       else
-        __configure_core(slot, value) rescue nil
+        begin
+          __configure_core(slot, value)
+        rescue => e
+          if current_configinfo.has_key?(slot.to_s)
+            # error on known option
+            fail e
+          else
+            # unknown option
+            nil
+          end
+        end
       end
     end
     self
@@ -3818,6 +3870,12 @@ module TkConfigMethod
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __optkey_aliases.find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__val2ruby_optkeys().keys.join('|')})$/
             method = _symbolkey2str(__val2ruby_optkeys())[slot]
@@ -4191,6 +4249,12 @@ module TkConfigMethod
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __optkey_aliases.find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__val2ruby_optkeys().keys.join('|')})$/
             method = _symbolkey2str(__val2ruby_optkeys())[slot]
@@ -4786,6 +4850,13 @@ class TkWindow<TkObject
           fontkeys[fkey] = keys.delete(fkey) if keys.key?(fkey)
         }
 
+        __optkey_aliases.each{|alias_name, real_name|
+          alias_name = alias_name.to_s
+          if keys.has_key?(alias_name)
+            keys[real_name.to_s] = keys.delete(alias_name)
+          end
+        }
+
         __methodcall_optkeys.each{|key|
           key = key.to_s
           methodkeys[key] = keys.delete(key) if keys.key?(key)
@@ -4823,18 +4894,24 @@ class TkWindow<TkObject
       else
         begin
           tk_call_without_enc(cmd, @path, *hash_kv(keys, true))
-        rescue
+        rescue => e
           tk_call_without_enc(cmd, @path)
           keys = __check_available_configure_options(keys)
           unless keys.empty?
             begin
-              tk_call_without_enc('destroy', @path)
-            rescue
-              # cannot destroy
+              # try to configure
               configure(keys)
-            else
-              # re-create widget
-              tk_call_without_enc(cmd, @path, *hash_kv(keys, true))
+            rescue
+              # fail => includes options adaptable when creattion only?
+              begin
+                tk_call_without_enc('destroy', @path)
+              rescue
+                # cannot rescue options error
+                fail e 
+              else
+                # re-create widget
+                tk_call_without_enc(cmd, @path, *hash_kv(keys, true))
+              end
             end
           end
         end
@@ -5389,7 +5466,7 @@ TkWidget = TkWindow
 #Tk.freeze
 
 module Tk
-  RELEASE_DATE = '2008-05-16'.freeze
+  RELEASE_DATE = '2008-05-23'.freeze
 
   autoload :AUTO_PATH,        'tk/variable'
   autoload :TCL_PACKAGE_PATH, 'tk/variable'
diff --git a/ext/tk/lib/tk/canvas.rb b/ext/tk/lib/tk/canvas.rb
index fceadd5e9c..36ea008a17 100644
--- a/ext/tk/lib/tk/canvas.rb
+++ b/ext/tk/lib/tk/canvas.rb
@@ -168,6 +168,8 @@ class Tk::Canvas<TkWindow
     #tk_tcl2ruby(tk_send_without_enc('canvasy', screen_y, *args))
     number(tk_send_without_enc('canvasy', screen_y, *args))
   end
+  alias canvas_x canvasx
+  alias canvas_y canvasy
 
   def coords(tag, *args)
     if args == []
@@ -642,6 +644,13 @@ class TkcItem<TkObject
         fontkeys[fkey] = keys.delete(fkey) if keys.key?(fkey)
       }
 
+      __item_optkey_aliases(nil).each{|alias_name, real_name|
+        alias_name = alias_name.to_s
+        if keys.has_key?(alias_name)
+          keys[real_name.to_s] = keys.delete(alias_name)
+        end
+      }
+
       __item_methodcall_optkeys(nil).each{|key|
         key = key.to_s
         methodkeys[key] = keys.delete(key) if keys.key?(key)
diff --git a/ext/tk/lib/tk/canvastag.rb b/ext/tk/lib/tk/canvastag.rb
index 7feea1575c..49796d80b2 100644
--- a/ext/tk/lib/tk/canvastag.rb
+++ b/ext/tk/lib/tk/canvastag.rb
@@ -63,6 +63,9 @@ module TkcTagAccess
   def cget(option)
     @c.itemcget(@id, option)
   end
+  def cget_strict(option)
+    @c.itemcget_strict(@id, option)
+  end
 
   def configure(key, value=None)
     @c.itemconfigure(@id, key, value)
diff --git a/ext/tk/lib/tk/composite.rb b/ext/tk/lib/tk/composite.rb
index 728b02f608..883d43c3ea 100644
--- a/ext/tk/lib/tk/composite.rb
+++ b/ext/tk/lib/tk/composite.rb
@@ -181,6 +181,57 @@ module TkComposite
     delegate_alias(option, option, *wins)
   end
 
+  def __cget_delegates(slot)
+    slot = slot.to_s
+
+    if @option_methods.include?(slot)
+      if @option_methods[slot][:cget]
+        return self.__send__(@option_methods[slot][:cget])
+      else
+        if @option_setting[slot]
+          return @option_setting[slot]
+        else
+          return ''
+        end
+      end
+    end
+
+    tbl = @delegates[slot]
+    tbl = @delegates['DEFAULT'] unless tbl
+
+    begin
+      if tbl
+        opt, wins = tbl[-1]
+        opt = slot if opt == 'DEFAULT'
+        if wins && wins[-1]
+          # return wins[-1].cget(opt)
+          return wins[-1].cget_strict(opt)
+        end
+      end
+    rescue
+    end
+
+    return None
+  end
+  private :__cget_delegates
+
+  def cget(slot)
+    if (ret = __cget_delegates(slot)) == None
+      super(slot)
+    else
+      ret
+    end
+  end
+
+  def cget_strict(slot)
+    if (ret = __cget_delegates(slot)) == None
+      super(slot)
+    else
+      ret
+    end
+  end
+
+=begin
   def cget(slot)
     slot = slot.to_s
 
@@ -212,6 +263,7 @@ module TkComposite
 
     super(slot)
   end
+=end
 
   def configure(slot, value=None)
     if slot.kind_of? Hash
diff --git a/ext/tk/lib/tk/image.rb b/ext/tk/lib/tk/image.rb
index 57f82cb812..dffdc19644 100644
--- a/ext/tk/lib/tk/image.rb
+++ b/ext/tk/lib/tk/image.rb
@@ -156,7 +156,7 @@ class TkPhotoImage<TkImage
     self
   end
 
-  def cget(option)
+  def cget_strict(option)
     case option.to_s
     when 'data', 'file'
       tk_send 'cget', '-' << option.to_s
@@ -164,6 +164,23 @@ class TkPhotoImage<TkImage
       tk_tcl2ruby(tk_send('cget', '-' << option.to_s))
     end
   end
+  def cget(option)
+    unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      cget_strict(option)
+    else
+      begin
+        cget_strict(option)
+      rescue => e
+        if current_configinfo.has_key?(option.to_s)
+          # error on known option
+          fail e
+        else
+          # unknown option
+          nil
+        end
+      end
+    end
+  end
 
   def copy(src, *opts)
     if opts.size == 0
diff --git a/ext/tk/lib/tk/itemconfig.rb b/ext/tk/lib/tk/itemconfig.rb
index abff676d78..9c6a98d0f8 100644
--- a/ext/tk/lib/tk/itemconfig.rb
+++ b/ext/tk/lib/tk/itemconfig.rb
@@ -8,6 +8,11 @@ require 'tk/itemfont.rb'
 module TkItemConfigOptkeys
   include TkUtil
 
+  def __item_optkey_aliases(id)
+    {}
+  end
+  private :__item_optkey_aliases
+
   def __item_numval_optkeys(id)
     []
   end
@@ -165,6 +170,11 @@ module TkItemConfigMethod
       fail ArgumentError, "Invalid option `#{orig_opt.inspect}'"
     end
 
+    alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == option}
+    if real_name
+      option = real_name.to_s
+    end
+
     if ( method = _symbolkey2str(__item_val2ruby_optkeys(tagid(tagOrId)))[option] )
       optval = tk_call_without_enc(*(__item_cget_cmd(tagid(tagOrId)) << "-#{option}"))
       begin
@@ -242,20 +252,35 @@ module TkItemConfigMethod
         __itemcget_core(tagOrId, option)
       rescue => e
         begin
-          __itemcget_core(tagOrId)
-          # not tag error -> option is unknown
-          nil
+          if __current_itemconfiginfo(tagOrId).has_key?(option.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
         rescue
           fail e  # tag error
         end
       end
     end
   end
+  def itemcget_strict(tagOrId, option)
+    # never use TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+    __itemcget_core(tagOrId, option)
+  end
 
   def __itemconfigure_core(tagOrId, slot, value=None)
     if slot.kind_of? Hash
       slot = _symbolkey2str(slot)
 
+      __item_optkey_aliases(tagid(tagOrId)).each{|alias_name, real_name|
+        alias_name = alias_name.to_s
+        if slot.has_key?(alias_name)
+          slot[real_name.to_s] = slot.delete(alias_name)
+        end
+      }
+
       __item_methodcall_optkeys(tagid(tagOrId)).each{|key, method|
         value = slot.delete(key.to_s)
         self.__send__(method, tagOrId, value) if value
@@ -292,6 +317,11 @@ module TkItemConfigMethod
         fail ArgumentError, "Invalid option `#{orig_slot.inspect}'"
       end
 
+      alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == slot}
+      if real_name
+        slot = real_name.to_s
+      end
+
       if ( conf = __item_keyonly_optkeys(tagid(tagOrId)).find{|k, v| k.to_s == slot } )
         defkey, undefkey = conf
         if value
@@ -350,8 +380,13 @@ module TkItemConfigMethod
           __itemconfigure_core(tagOrId, slot, value)
         rescue => e
           begin
-            __itemconfiginfo_core(tagOrId)
-            # not tag error -> option is unknown
+            if __current_itemconfiginfo(tagOrId).has_key?(slot.to_s)
+              # not tag error & option is known -> error on known option
+              fail e
+            else
+              # not tag error & option is unknown
+              nil
+            end
           rescue
             fail e  # tag error
           end
@@ -386,6 +421,12 @@ module TkItemConfigMethod
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__item_val2ruby_optkeys(tagid(tagOrId)).keys.join('|')})$/
             method = _symbolkey2str(__item_val2ruby_optkeys(tagid(tagOrId)))[slot]
@@ -757,6 +798,12 @@ module TkItemConfigMethod
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__item_val2ruby_optkeys(tagid(tagOrId)).keys.join('|')})$/
             method = _symbolkey2str(__item_val2ruby_optkeys(tagid(tagOrId)))[slot]
diff --git a/ext/tk/lib/tk/itemfont.rb b/ext/tk/lib/tk/itemfont.rb
index 11d443b597..4c5c917c57 100644
--- a/ext/tk/lib/tk/itemfont.rb
+++ b/ext/tk/lib/tk/itemfont.rb
@@ -94,11 +94,14 @@ module TkTreatItemFont
                                       *(__item_config_cmd(tagid(tagOrId)) << {}))
               next
             else
-              begin
+              fnt = hash_kv(fnt) if fnt.kind_of?(Hash)
+              unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
                 tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << fnt))
-              rescue => e
-                unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-                  fail e
+              else
+                begin
+                  tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << fnt))
+                rescue => e
+                  # ignore
                 end
               end
             end
@@ -153,11 +156,14 @@ module TkTreatItemFont
       elsif Tk::JAPANIZED_TK
         fobj = fontobj          # create a new TkFont object
       else
-        begin
+        ltn = hash_kv(ltn) if ltn.kind_of?(Hash)
+        unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
           tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << ltn))
-        rescue => e
-          unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-            fail e
+        else
+          begin
+            tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << ltn))
+          rescue => e
+            # ignore
           end
         end
         next
@@ -210,11 +216,14 @@ module TkTreatItemFont
       elsif Tk::JAPANIZED_TK
         fobj = fontobj          # create a new TkFont object
       else
-        begin
+        knj = hash_kv(knj) if knj.kind_of?(Hash)
+        unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
           tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << knj))
-        rescue => e
-          unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
-            fail e
+        else
+          begin
+            tk_call(*(__item_config_cmd(tagid(tagOrId)) << "-#{optkey}" << knj))
+          rescue => e
+            # ignore
           end
         end
         next
diff --git a/ext/tk/lib/tk/menu.rb b/ext/tk/lib/tk/menu.rb
index 8ba3156293..3ae0548dd1 100644
--- a/ext/tk/lib/tk/menu.rb
+++ b/ext/tk/lib/tk/menu.rb
@@ -34,12 +34,13 @@ module TkMenuEntryConfig
   private :__item_val2ruby_optkeys
 
   alias entrycget itemcget
+  alias entrycget_strict itemcget_strict
   alias entryconfigure itemconfigure
   alias entryconfiginfo itemconfiginfo
   alias current_entryconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 class Tk::Menu<TkWindow
@@ -518,7 +519,7 @@ class Tk::Menubutton<Tk::Label
           tk_call_without_enc(self.class::TkCommandNames[0], @path)
           keys = __check_available_configure_options(keys)
           unless keys.empty?
-            tk_call_without_enc('destroy', @path)
+            tk_call_without_enc('destroy', @path) rescue nil
             tk_call_without_enc(self.class::TkCommandNames[0], @path, 
                                 *hash_kv(keys, true))
           end
@@ -642,6 +643,9 @@ class Tk::OptionMenubutton<Tk::Menubutton
   def menucget(key)
     @menu.cget(key)
   end
+  def menucget_strict(key)
+    @menu.cget_strict(key)
+  end
   def menuconfigure(key, val=None)
     @menu.configure(key, val)
     self
@@ -655,6 +659,9 @@ class Tk::OptionMenubutton<Tk::Menubutton
   def entrycget(index, key)
     @menu.entrycget(index, key)
   end
+  def entrycget_strict(index, key)
+    @menu.entrycget_strict(index, key)
+  end
   def entryconfigure(index, key, val=None)
     @menu.entryconfigure(index, key, val)
     self
diff --git a/ext/tk/lib/tk/namespace.rb b/ext/tk/lib/tk/namespace.rb
index 9d2213ff51..20a8d65215 100644
--- a/ext/tk/lib/tk/namespace.rb
+++ b/ext/tk/lib/tk/namespace.rb
@@ -83,6 +83,20 @@ class TkNamespace < TkObject
         super(slot)
       end
     end
+    def cget_strict(slot)
+      if slot == :namespace || slot == 'namespace'
+        ns = super(slot)
+        Tk_Namespace_ID_TBL.mutex.synchronize{
+          if TkNamespace::Tk_Namespace_ID_TBL.key?(ns)
+            TkNamespace::Tk_Namespace_ID_TBL[ns]
+          else
+            ns
+          end
+        }
+      else
+        super(slot)
+      end
+    end
 
     def configinfo(slot = nil)
       if slot
diff --git a/ext/tk/lib/tk/panedwindow.rb b/ext/tk/lib/tk/panedwindow.rb
index ba8a7e9743..030144e677 100644
--- a/ext/tk/lib/tk/panedwindow.rb
+++ b/ext/tk/lib/tk/panedwindow.rb
@@ -76,11 +76,32 @@ class Tk::PanedWindow<TkWindow
     self
   end
 
-  def panecget(win, key)
+  def panecget_strict(win, key)
     # win = win.epath if win.kind_of?(TkObject)
     win = _epath(win)
     tk_tcl2ruby(tk_send_without_enc('panecget', win, "-#{key}"))
   end
+  def panecget(win, key)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      panecget_strict(win, key)
+    else
+      begin
+        panecget_strict(win, key)
+      rescue => e
+        begin
+          if current_paneconfiginfo(win).has_key?(option.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
+    end
+  end
 
   def paneconfigure(win, key, value=nil)
     # win = win.epath if win.kind_of?(TkObject)
diff --git a/ext/tk/lib/tk/text.rb b/ext/tk/lib/tk/text.rb
index a4c63c70a3..4ec82bed1d 100644
--- a/ext/tk/lib/tk/text.rb
+++ b/ext/tk/lib/tk/text.rb
@@ -32,6 +32,9 @@ module TkTextTagConfig
   def tag_cget(tagOrId, option)
     itemcget(['tag', tagOrId], option)
   end
+  def tag_cget_strict(tagOrId, option)
+    itemcget_strict(['tag', tagOrId], option)
+  end
   def tag_configure(tagOrId, slot, value=None)
     itemconfigure(['tag', tagOrId], slot, value)
   end
@@ -45,6 +48,9 @@ module TkTextTagConfig
   def window_cget(tagOrId, option)
     itemcget(['window', tagOrId], option)
   end
+  def window_cget_strict(tagOrId, option)
+    itemcget_strict(['window', tagOrId], option)
+  end
   def window_configure(tagOrId, slot, value=None)
     itemconfigure(['window', tagOrId], slot, value)
   end
@@ -55,8 +61,8 @@ module TkTextTagConfig
     current_itemconfiginfo(['window', tagOrId], slot)
   end
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 class Tk::Text<TkTextWin
@@ -403,7 +409,7 @@ class Tk::Text<TkTextWin
   end
   alias previous_mark mark_previous
 
-  def image_cget(index, slot)
+  def image_cget_strict(index, slot)
     case slot.to_s
     when 'text', 'label', 'show', 'data', 'file'
       _fromUTF8(tk_send_without_enc('image', 'cget', 
@@ -415,6 +421,28 @@ class Tk::Text<TkTextWin
     end
   end
 
+  def image_cget(index, slot)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      image_cget_strict(index, slot)
+    else
+      begin
+        image_cget_strict(index, slot)
+      rescue => e
+        begin
+          if current_image_configinfo(index).has_key?(slot.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
+    end
+  end
+
   def image_configure(index, slot, value=None)
     if slot.kind_of?(Hash)
       _fromUTF8(tk_send_without_enc('image', 'configure', 
diff --git a/ext/tk/lib/tk/textimage.rb b/ext/tk/lib/tk/textimage.rb
index d4c973213d..fb306a9c17 100644
--- a/ext/tk/lib/tk/textimage.rb
+++ b/ext/tk/lib/tk/textimage.rb
@@ -52,6 +52,10 @@ class TkTextImage<TkObject
     @t.image_cget(@index, slot)
   end
 
+  def cget_strict(slot)
+    @t.image_cget_strict(@index, slot)
+  end
+
   def configure(slot, value=None)
     @t.image_configure(@index, slot, value)
     self
diff --git a/ext/tk/lib/tk/texttag.rb b/ext/tk/lib/tk/texttag.rb
index 792d544fe7..b08d923ea1 100644
--- a/ext/tk/lib/tk/texttag.rb
+++ b/ext/tk/lib/tk/texttag.rb
@@ -132,6 +132,9 @@ class TkTextTag<TkObject
   def cget(key)
     @t.tag_cget @id, key
   end
+  def cget_strict(key)
+    @t.tag_cget_strict @id, key
+  end
 =begin
   def cget(key)
     case key.to_s
diff --git a/ext/tk/lib/tk/textwindow.rb b/ext/tk/lib/tk/textwindow.rb
index a577329358..004422e4f3 100644
--- a/ext/tk/lib/tk/textwindow.rb
+++ b/ext/tk/lib/tk/textwindow.rb
@@ -72,6 +72,9 @@ class TkTextWindow<TkObject
   def cget(slot)
     @t.window_cget(@index, slot)
   end
+  def cget_strict(slot)
+    @t.window_cget_strict(@index, slot)
+  end
 
   def configure(slot, value=None)
     if slot.kind_of?(Hash)
diff --git a/ext/tk/lib/tkextlib/blt/component.rb b/ext/tk/lib/tkextlib/blt/component.rb
index dd387634ee..b2005b2f2b 100644
--- a/ext/tk/lib/tkextlib/blt/component.rb
+++ b/ext/tk/lib/tkextlib/blt/component.rb
@@ -85,6 +85,9 @@ module Tk::BLT
     def axis_cget(id, option)
       ret = itemcget(['axis', tagid(id)], option)
     end
+    def axis_cget_strict(id, option)
+      ret = itemcget_strict(['axis', tagid(id)], option)
+    end
     def axis_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -118,6 +121,9 @@ module Tk::BLT
     def crosshairs_cget(option)
       itemcget('crosshairs', option)
     end
+    def crosshairs_cget_strict(option)
+      itemcget_strict('crosshairs', option)
+    end
     def crosshairs_configure(slot, value=None)
       itemconfigure('crosshairs', slot, value)
     end
@@ -131,6 +137,9 @@ module Tk::BLT
     def element_cget(id, option)
       itemcget(['element', tagid(id)], option)
     end
+    def element_cget_strict(id, option)
+      itemcget_strict(['element', tagid(id)], option)
+    end
     def element_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -152,6 +161,9 @@ module Tk::BLT
     def bar_cget(id, option)
       itemcget(['bar', tagid(id)], option)
     end
+    def bar_cget_strict(id, option)
+      itemcget_strict(['bar', tagid(id)], option)
+    end
     def bar_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -173,6 +185,9 @@ module Tk::BLT
     def line_cget(id, option)
       itemcget(['line', tagid(id)], option)
     end
+    def line_cget_strict(id, option)
+      itemcget_strict(['line', tagid(id)], option)
+    end
     def line_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -194,6 +209,9 @@ module Tk::BLT
     def gridline_cget(option)
       itemcget('grid', option)
     end
+    def gridline_cget_strict(option)
+      itemcget_strict('grid', option)
+    end
     def gridline_configure(slot, value=None)
       itemconfigure('grid', slot, value)
     end
@@ -207,6 +225,9 @@ module Tk::BLT
     def legend_cget(option)
       itemcget('legend', option)
     end
+    def legend_cget_strict(option)
+      itemcget_strict('legend', option)
+    end
     def legend_configure(slot, value=None)
       itemconfigure('legend', slot, value)
     end
@@ -220,6 +241,9 @@ module Tk::BLT
     def pen_cget(id, option)
       itemcget(['pen', tagid(id)], option)
     end
+    def pen_cget_strict(id, option)
+      itemcget_strict(['pen', tagid(id)], option)
+    end
     def pen_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -241,6 +265,9 @@ module Tk::BLT
     def postscript_cget(option)
       itemcget('postscript', option)
     end
+    def postscript_cget_strict(option)
+      itemcget_strict('postscript', option)
+    end
     def postscript_configure(slot, value=None)
       itemconfigure('postscript', slot, value)
     end
@@ -254,6 +281,9 @@ module Tk::BLT
     def marker_cget(id, option)
       itemcget(['marker', tagid(id)], option)
     end
+    def marker_cget_strict(id, option)
+      itemcget_strict(['marker', tagid(id)], option)
+    end
     def marker_configure(*args)
       slot = args.pop
       if slot.kind_of?(Hash)
@@ -273,11 +303,12 @@ module Tk::BLT
     end
 
     alias __itemcget itemcget
+    alias __itemcget_strict itemcget_strict
     alias __itemconfiginfo itemconfiginfo
     alias __current_itemconfiginfo current_itemconfiginfo
     private :__itemcget, :__itemconfiginfo, :__current_itemconfiginfo
 
-    def itemcget(tagOrId, option)
+    def itemcget_strict(tagOrId, option)
       ret = __itemcget(tagid(tagOrId), option)
       if option == 'bindtags' || option == :bindtags
         ret.collect{|tag| TkBindTag.id2obj(tag)}
@@ -285,6 +316,27 @@ module Tk::BLT
         ret
       end
     end
+    def itemcget(tagOrId, option)
+      unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+        itemcget_strict(tagOrId, option)
+      else
+        begin
+          itemcget_strict(tagOrId, option)
+        rescue => e
+          begin
+            if current_itemconfiginfo(tagOrId).has_key?(option.to_s)
+              # error on known option
+              fail e
+            else
+              # unknown option
+              nil
+            end
+          rescue
+            fail e  # tag error
+          end
+        end
+      end
+    end
     def itemconfiginfo(tagOrId, slot = nil)
       ret = __itemconfiginfo(tagid(tagOrId), slot)
 
@@ -321,8 +373,8 @@ module Tk::BLT
       ret
     end
 
-    private :itemcget, :itemconfigure
-    private :itemconfiginfo, :current_itemconfiginfo
+    private :itemcget, :itemcget_strict
+    private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
     #################
 
@@ -428,6 +480,9 @@ module Tk::BLT
       def cget(option)
         @chart.axis_cget(@id, option)
       end
+      def cget_strict(option)
+        @chart.axis_cget_strict(@id, option)
+      end
       def configure(key, value=None)
         @chart.axis_configure(@id, key, value)
         self
@@ -530,6 +585,9 @@ module Tk::BLT
       def cget(option)
         @chart.crosshair_cget(option)
       end
+      def cget_strict(option)
+        @chart.crosshair_cget_strict(option)
+      end
       def configure(key, value=None)
         @chart.crosshair_configure(key, value)
         self
@@ -675,6 +733,9 @@ module Tk::BLT
         # @chart.element_cget(@id, option)
         @chart.__send__(@typename + '_cget', @id, option)
       end
+      def cget_strict(option)
+        @chart.__send__(@typename + '_cget_strict', @id, option)
+      end
       def configure(key, value=None)
         # @chart.element_configure(@id, key, value)
         @chart.__send__(@typename + '_configure', @id, key, value)
@@ -775,6 +836,9 @@ module Tk::BLT
       def cget(option)
         @chart.gridline_cget(option)
       end
+      def cget_strict(option)
+        @chart.gridline_cget_strict(option)
+      end
       def configure(key, value=None)
         @chart.gridline_configure(key, value)
         self
@@ -846,6 +910,9 @@ module Tk::BLT
       def cget(option)
         @chart.legend_cget(option)
       end
+      def cget_strict(option)
+        @chart.legend_cget_strict(option)
+      end
       def configure(key, value=None)
         @chart.legend_configure(key, value)
         self
@@ -972,6 +1039,9 @@ module Tk::BLT
       def cget(option)
         @chart.pen_cget(@id, option)
       end
+      def cget_strict(option)
+        @chart.pen_cget_strict(@id, option)
+      end
       def configure(key, value=None)
         @chart.pen_configure(@id, key, value)
         self
@@ -1039,6 +1109,9 @@ module Tk::BLT
       def cget(option)
         @chart.postscript_cget(option)
       end
+      def cget_strict(option)
+        @chart.postscript_cget_strict(option)
+      end
       def configure(key, value=None)
         @chart.postscript_configure(key, value)
         self
@@ -1117,6 +1190,13 @@ module Tk::BLT
             fontkeys[fkey] = keys.delete(fkey) if keys.key?(fkey)
           }
 
+          __item_optkey_aliases(nil).each{|alias_name, real_name|
+            alias_name = alias_name.to_s
+            if keys.has_key?(alias_name)
+              keys[real_name.to_s] = keys.delete(alias_name)
+            end
+          }
+
           __item_methodcall_optkeys(nil).each{|key|
             key = key.to_s
             methodkeys[key] = keys.delete(key) if keys.key?(key)
@@ -1192,6 +1272,9 @@ module Tk::BLT
       def cget(option)
         @chart.marker_cget(@id, option)
       end
+      def cget_strict(option)
+        @chart.marker_cget_strict(@id, option)
+      end
       def configure(key, value=None)
         @chart.marker_configure(@id, key, value)
         self
@@ -1774,6 +1857,9 @@ module Tk::BLT
     def xaxis_cget(option)
       itemcget('xaxis', option)
     end
+    def xaxis_cget_strict(option)
+      itemcget_strict('xaxis', option)
+    end
     def xaxis_configure(slot, value=None)
       if slot.kind_of?(Hash)
         slot = _symbolkey2str(slot)
@@ -1843,6 +1929,9 @@ module Tk::BLT
     def x2axis_cget(option)
       itemcget('x2axis', option)
     end
+    def x2axis_cget_strict(option)
+      itemcget_strict('x2axis', option)
+    end
     def x2axis_configure(slot, value=None)
       if slot.kind_of?(Hash)
         slot = _symbolkey2str(slot)
@@ -1912,6 +2001,9 @@ module Tk::BLT
     def yaxis_cget(option)
       itemcget('yaxis', option)
     end
+    def yaxis_cget_strict(option)
+      itemcget_strict('yaxis', option)
+    end
     def yaxis_configure(slot, value=None)
       if slot.kind_of?(Hash)
         slot = _symbolkey2str(slot)
@@ -1981,6 +2073,9 @@ module Tk::BLT
     def y2axis_cget(option)
       itemcget('y2axis', option)
     end
+    def y2axis_cget_strict(option)
+      itemcget_strict('y2axis', option)
+    end
     def y2axis_configure(slot, value=None)
       if slot.kind_of?(Hash)
         slot = _symbolkey2str(slot)
diff --git a/ext/tk/lib/tkextlib/blt/htext.rb b/ext/tk/lib/tkextlib/blt/htext.rb
index a0cf3dc036..0d9cb30185 100644
--- a/ext/tk/lib/tkextlib/blt/htext.rb
+++ b/ext/tk/lib/tkextlib/blt/htext.rb
@@ -22,6 +22,7 @@ module Tk::BLT
     WidgetClassNames[WidgetClassName] = self
 
     alias window_cget itemcget
+    alias window_cget_strict itemcget_strict
     alias window_configure itemconfigure
     alias window_configuinfo itemconfiginfo
     alias current_window_configuinfo current_itemconfiginfo
diff --git a/ext/tk/lib/tkextlib/blt/table.rb b/ext/tk/lib/tkextlib/blt/table.rb
index 0be9d8d42a..dfa10269ed 100644
--- a/ext/tk/lib/tkextlib/blt/table.rb
+++ b/ext/tk/lib/tkextlib/blt/table.rb
@@ -29,6 +29,9 @@ module Tk::BLT
       def blt_table_cget(*args)
         Tk::BLT::Table.cget(self, *args)
       end
+      def blt_table_cget_strict(*args)
+        Tk::BLT::Table.cget_strict(self, *args)
+      end
 
       def blt_table_configure(*args)
         Tk::BLT::Table.configure(self, *args)
@@ -92,6 +95,9 @@ module Tk::BLT
       def blt_table_itemcget(*args)
         Tk::BLT::Table.itemcget(self, *args)
       end
+      def blt_table_itemcget_strict(*args)
+        Tk::BLT::Table.itemcget_strict(self, *args)
+      end
 
       def blt_table_itemconfigure(*args)
         Tk::BLT::Table.itemconfigure(self, *args)
@@ -136,12 +142,13 @@ class << Tk::BLT::Table
   private :__item_pathname
 
   alias __itemcget itemcget
+  alias __itemcget_strict itemcget_strict
   alias __itemconfigure itemconfigure
   alias __itemconfiginfo itemconfiginfo
   alias __current_itemconfiginfo current_itemconfiginfo
 
-  private :__itemcget, :__itemconfigure
-  private :__itemconfiginfo, :__current_itemconfiginfo
+  private :__itemcget, :__itemcget_strict
+  private :__itemconfigure, :__itemconfiginfo, :__current_itemconfiginfo
 
   def __boolval_optkeys
     super() << 'propagate'
@@ -176,6 +183,9 @@ class << Tk::BLT::Table
   def cget(container, option)
     __itemcget([container], option)
   end
+  def cget_strict(container, option)
+    __itemcget_strict([container], option)
+  end
 
   def configure(container, *args)
     __itemconfigure([container], *args)
@@ -192,6 +202,9 @@ class << Tk::BLT::Table
   def itemcget(container, item, option)
     __itemcget([container, tagid(item)], option)
   end
+  def itemcget_strict(container, item, option)
+    __itemcget_strict([container, tagid(item)], option)
+  end
 
   def itemconfigure(container, *args)
     if args[-1].kind_of?(Hash)
diff --git a/ext/tk/lib/tkextlib/blt/tabset.rb b/ext/tk/lib/tkextlib/blt/tabset.rb
index 1a0f312c4c..ca81ad8f95 100644
--- a/ext/tk/lib/tkextlib/blt/tabset.rb
+++ b/ext/tk/lib/tkextlib/blt/tabset.rb
@@ -128,6 +128,9 @@ module Tk::BLT
       def cget(*args)
         @t.tab_cget(@id, *args)
       end
+      def cget_strict(*args)
+        @t.tab_cget_strict(@id, *args)
+      end
       def configure(*args)
         @t.tab_configure(@id, *args)
       end
@@ -240,6 +243,7 @@ module Tk::BLT
     private :__item_pathname
 
     alias tab_cget itemcget
+    alias tab_cget_strict itemcget_strict
     alias tab_configure itemconfigure
     alias tab_configinfo itemconfiginfo
     alias current_tab_configinfo current_itemconfiginfo
diff --git a/ext/tk/lib/tkextlib/blt/ted.rb b/ext/tk/lib/tkextlib/blt/ted.rb
index 8b727c1eec..670265fc78 100644
--- a/ext/tk/lib/tkextlib/blt/ted.rb
+++ b/ext/tk/lib/tkextlib/blt/ted.rb
@@ -30,12 +30,15 @@ module Tk::BLT
       end
       private :__item_config_cmd
 
-      private :itemcget, :itemconfigure
-      private :itemconfiginfo, :current_itemconfiginfo
+      private :itemcget, :itemcget_strict
+      private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
       def cget(master, option)
         itemcget(master, option)
       end
+      def cget_strict(master, option)
+        itemcget_strict(master, option)
+      end
       def configure(master, slot, value=None)
         itemconfigure(master, slot, value)
       end
diff --git a/ext/tk/lib/tkextlib/blt/treeview.rb b/ext/tk/lib/tkextlib/blt/treeview.rb
index 672869bfa2..c5a5697186 100644
--- a/ext/tk/lib/tkextlib/blt/treeview.rb
+++ b/ext/tk/lib/tkextlib/blt/treeview.rb
@@ -98,6 +98,9 @@ module Tk::BLT::Treeview::ConfigMethod
   def column_cget(name, option)
     itemcget(['column', name], option)
   end
+  def column_cget_strict(name, option)
+    itemcget_strict(['column', name], option)
+  end
   def column_configure(name, slot, value=None)
     itemconfigure(['column', name], slot, value)
   end
@@ -111,6 +114,9 @@ module Tk::BLT::Treeview::ConfigMethod
   def button_cget(option)
     itemcget('button', option)
   end
+  def button_cget_strict(option)
+    itemcget_strict('button', option)
+  end
   def button_configure(slot, value=None)
     itemconfigure('button', slot, value)
   end
@@ -129,6 +135,14 @@ module Tk::BLT::Treeview::ConfigMethod
       ret
     end
   end
+  def entry_cget_strict(option)
+    ret = itemcget_strict('entry', option)
+    if option == 'bindtags' || option == :bindtags
+      ret.collect{|tag| TkBindTag.id2obj(tag)}
+    else
+      ret
+    end
+  end
   def entry_configure(slot, value=None)
     itemconfigure('entry', slot, value)
   end
@@ -170,6 +184,9 @@ module Tk::BLT::Treeview::ConfigMethod
   def sort_cget(option)
     itemcget('sort', option)
   end
+  def sort_cget_strict(option)
+    itemcget_strict('sort', option)
+  end
   def sort_configure(slot, value=None)
     itemconfigure('sort', slot, value)
   end
@@ -183,6 +200,9 @@ module Tk::BLT::Treeview::ConfigMethod
   def text_cget(option)
     itemcget('text', option)
   end
+  def text_cget_strict(option)
+    itemcget_strict('text', option)
+  end
   def text_configure(slot, value=None)
     itemconfigure('text', slot, value)
   end
@@ -193,8 +213,8 @@ module Tk::BLT::Treeview::ConfigMethod
     current_itemconfiginfo('text', slot)
   end
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 class Tk::BLT::Treeview
diff --git a/ext/tk/lib/tkextlib/blt/unix_dnd.rb b/ext/tk/lib/tkextlib/blt/unix_dnd.rb
index 7a994233a2..445002d7a5 100644
--- a/ext/tk/lib/tkextlib/blt/unix_dnd.rb
+++ b/ext/tk/lib/tkextlib/blt/unix_dnd.rb
@@ -30,12 +30,15 @@ module Tk::BLT
       end
       private :__item_config_cmd
 
-      private :itemcget, :itemconfigure
-      private :itemconfiginfo, :current_itemconfiginfo
+      private :itemcget, :itemcget_strict
+      private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
       def cget(win, option)
         itemcget(['cget', win], option)
       end
+      def cget_strict(win, option)
+        itemcget_strict(['cget', win], option)
+      end
       def configure(win, slot, value=None)
         itemconfigure(['configure', win], slot, value)
       end
@@ -49,6 +52,9 @@ module Tk::BLT
       def token_cget(win, option)
         itemcget(['token', 'cget', win], option)
       end
+      def token_cget_strict(win, option)
+        itemcget_strict(['token', 'cget', win], option)
+      end
       def token_configure(win, slot, value=None)
         itemconfigure(['token', 'configure', win], slot, value)
       end
diff --git a/ext/tk/lib/tkextlib/blt/watch.rb b/ext/tk/lib/tkextlib/blt/watch.rb
index 2daf417e0b..219ff78e97 100644
--- a/ext/tk/lib/tkextlib/blt/watch.rb
+++ b/ext/tk/lib/tkextlib/blt/watch.rb
@@ -146,7 +146,7 @@ module Tk::BLT
         end
       end
     end
-    def cget(key)
+    def cget_strict(key)
       key = key.to_s
       begin
         info.assoc(key)[1]
@@ -154,5 +154,22 @@ module Tk::BLT
         fail ArgumentError, "unknown option '#{key}'"
       end
     end
+    def cget(key)
+      unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+        cget_strict(key)
+      else
+        begin
+          cget_strict(key)
+        rescue => e
+          if current_configinfo.has_key?(key.to_s)
+            # error on known option
+            fail e
+          else
+            # unknown option
+            nil
+          end
+        end
+      end
+    end
   end
 end
diff --git a/ext/tk/lib/tkextlib/bwidget/dialog.rb b/ext/tk/lib/tkextlib/bwidget/dialog.rb
index 0ddee21d05..291ca4a962 100644
--- a/ext/tk/lib/tkextlib/bwidget/dialog.rb
+++ b/ext/tk/lib/tkextlib/bwidget/dialog.rb
@@ -59,6 +59,13 @@ class Tk::BWidget::Dialog
     end
   end
 
+  def cget_strict(slot)
+    if slot.to_s == 'relative'
+      super('parent')
+    else
+      super(slot)
+    end
+  end
   def cget(slot)
     if slot.to_s == 'relative'
       super('parent')
diff --git a/ext/tk/lib/tkextlib/bwidget/dynamichelp.rb b/ext/tk/lib/tkextlib/bwidget/dynamichelp.rb
index 224304f2ab..846e58062d 100644
--- a/ext/tk/lib/tkextlib/bwidget/dynamichelp.rb
+++ b/ext/tk/lib/tkextlib/bwidget/dynamichelp.rb
@@ -34,6 +34,13 @@ module Tk::BWidget::DynamicHelp
     ['DynamicHelp::configure']
   end
 
+  def self.cget_strict(slot)
+    slot = slot.to_s
+    info = {}
+    self.current_configinfo.each{|k,v| info[k.to_s] = v if k.to_s == slot}
+    fail RuntimeError, "unknown option \"-#{slot}\""  if info.empty?
+    info.values[0]
+  end
   def self.cget(slot)
     self.current_configinfo(slot).values[0]
   end
diff --git a/ext/tk/lib/tkextlib/bwidget/listbox.rb b/ext/tk/lib/tkextlib/bwidget/listbox.rb
index d8cd72fec2..093fcb6fb3 100644
--- a/ext/tk/lib/tkextlib/bwidget/listbox.rb
+++ b/ext/tk/lib/tkextlib/bwidget/listbox.rb
@@ -297,6 +297,9 @@ class Tk::BWidget::ListBox::Item
   def cget(key)
     @listbox.itemcget(@id, key)
   end
+  def cget_strict(key)
+    @listbox.itemcget_strict(@id, key)
+  end
 
   def configure(key, val=None)
     @listbox.itemconfigure(@id, key, val)
diff --git a/ext/tk/lib/tkextlib/bwidget/messagedlg.rb b/ext/tk/lib/tkextlib/bwidget/messagedlg.rb
index cc8a996f46..b88461baf7 100644
--- a/ext/tk/lib/tkextlib/bwidget/messagedlg.rb
+++ b/ext/tk/lib/tkextlib/bwidget/messagedlg.rb
@@ -65,6 +65,17 @@ class Tk::BWidget::MessageDlg
     end
     @keys[slot]
   end
+  def cget_strict(slot)
+    slot = slot.to_s
+    if slot == 'relative'
+      slot = 'parent'
+    end
+    if winfo_exist?
+      val = super(slot)
+      @keys[slot] = val
+    end
+    @keys[slot]
+  end
 
   def configure(slot, value=None)
     if winfo_exist?
diff --git a/ext/tk/lib/tkextlib/bwidget/tree.rb b/ext/tk/lib/tkextlib/bwidget/tree.rb
index 7a46db575e..aed4512a73 100644
--- a/ext/tk/lib/tkextlib/bwidget/tree.rb
+++ b/ext/tk/lib/tkextlib/bwidget/tree.rb
@@ -358,6 +358,9 @@ class Tk::BWidget::Tree::Node
   def cget(key)
     @tree.itemcget(@id, key)
   end
+  def cget_strict(key)
+    @tree.itemcget_strict(@id, key)
+  end
 
   def configure(key, val=None)
     @tree.itemconfigure(@id, key, val)
diff --git a/ext/tk/lib/tkextlib/bwidget/widget.rb b/ext/tk/lib/tkextlib/bwidget/widget.rb
index 34e51308a5..a93364b567 100644
--- a/ext/tk/lib/tkextlib/bwidget/widget.rb
+++ b/ext/tk/lib/tkextlib/bwidget/widget.rb
@@ -29,6 +29,13 @@ module Tk::BWidget::Widget
     ['Widget::configure']
   end
 
+  def self.cget_strict(slot)
+    slot = slot.to_s
+    info = {}
+    self.current_configinfo.each{|k,v| info[k.to_s] = v if k.to_s == slot}
+    fail RuntimeError, "unknown option \"-#{slot}\""  if info.empty?
+    info.values[0]
+  end
   def self.cget(slot)
     self.current_configinfo(slot).values[0]
   end
@@ -105,9 +112,12 @@ module Tk::BWidget::Widget
     tk_call('Widget::setoption', win, option, value)
   end
 
-  def self.sub_cget(win, subwidget)
+  def self.sub_cget_strict(win, subwidget)
     tk_call('Widget::subcget', win, subwidget)
   end
+  def self.sub_cget(win, subwidget)
+    self.sub_cget_strict(win, subwidget)
+  end
 
   def self.sync_options(klass, subclass, subpath, options)
     tk_call('Widget::syncoptions', klass, subclass, subpath, options)
diff --git a/ext/tk/lib/tkextlib/iwidgets/buttonbox.rb b/ext/tk/lib/tkextlib/iwidgets/buttonbox.rb
index a055e07ac9..05d58c386f 100644
--- a/ext/tk/lib/tkextlib/iwidgets/buttonbox.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/buttonbox.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Buttonbox
   end
 
   alias buttoncget itemcget
+  alias buttoncget_strict itemcget_strict
   alias buttonconfigure itemconfigure
   alias buttonconfiginfo itemconfiginfo
   alias current_buttonconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/checkbox.rb b/ext/tk/lib/tkextlib/iwidgets/checkbox.rb
index 7d2b41f806..c85d356c55 100644
--- a/ext/tk/lib/tkextlib/iwidgets/checkbox.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/checkbox.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Checkbox
   end
 
   alias buttoncget itemcget
+  alias buttoncget_strict itemcget_strict
   alias buttonconfigure itemconfigure
   alias buttonconfiginfo itemconfiginfo
   alias current_buttonconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/dialogshell.rb b/ext/tk/lib/tkextlib/iwidgets/dialogshell.rb
index d6c668621d..8d43cc07ab 100644
--- a/ext/tk/lib/tkextlib/iwidgets/dialogshell.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/dialogshell.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Dialogshell
   end
 
   alias buttoncget itemcget
+  alias buttoncget_strict itemcget_strict
   alias buttonconfigure itemconfigure
   alias buttonconfiginfo itemconfiginfo
   alias current_buttonconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/menubar.rb b/ext/tk/lib/tkextlib/iwidgets/menubar.rb
index dea3d34c2a..5aaefbe50d 100644
--- a/ext/tk/lib/tkextlib/iwidgets/menubar.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/menubar.rb
@@ -62,12 +62,13 @@ class Tk::Iwidgets::Menubar
   end
 
   alias menucget itemcget
+  alias menucget_strict itemcget_strict
   alias menuconfigure itemconfigure
   alias menuconfiginfo itemconfiginfo
   alias current_menuconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/messagebox.rb b/ext/tk/lib/tkextlib/iwidgets/messagebox.rb
index 2bbbec7666..98ac32900c 100644
--- a/ext/tk/lib/tkextlib/iwidgets/messagebox.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/messagebox.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Messagebox
   private :__item_boolval_optkeys
 
   alias typecget itemcget
+  alias typecget_strict itemcget_strict
   alias typeconfigure itemconfigure
   alias typeconfiginfo itemconfiginfo
   alias current_typeconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/notebook.rb b/ext/tk/lib/tkextlib/iwidgets/notebook.rb
index 268452afec..03b50633df 100644
--- a/ext/tk/lib/tkextlib/iwidgets/notebook.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/notebook.rb
@@ -42,12 +42,13 @@ class Tk::Iwidgets::Notebook
   end
 
   alias pagecget itemcget
+  alias pagecget_strict itemcget_strict
   alias pageconfigure itemconfigure
   alias pageconfiginfo itemconfiginfo
   alias current_pageconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/panedwindow.rb b/ext/tk/lib/tkextlib/iwidgets/panedwindow.rb
index 035df0a5b8..3bf73d69fe 100644
--- a/ext/tk/lib/tkextlib/iwidgets/panedwindow.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/panedwindow.rb
@@ -42,12 +42,13 @@ class Tk::Iwidgets::Panedwindow
   end
 
   alias panecget itemcget
+  alias panecget_strict itemcget_strict
   alias paneconfigure itemconfigure
   alias paneconfiginfo itemconfiginfo
   alias current_paneconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/radiobox.rb b/ext/tk/lib/tkextlib/iwidgets/radiobox.rb
index cfcbca1aad..e9d9521252 100644
--- a/ext/tk/lib/tkextlib/iwidgets/radiobox.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/radiobox.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Radiobox
   end
 
   alias buttoncget itemcget
+  alias buttoncget_strict itemcget_strict
   alias buttonconfigure itemconfigure
   alias buttonconfiginfo itemconfiginfo
   alias current_buttonconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/scrolledtext.rb b/ext/tk/lib/tkextlib/iwidgets/scrolledtext.rb
index d85f232b37..d6436d202a 100644
--- a/ext/tk/lib/tkextlib/iwidgets/scrolledtext.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/scrolledtext.rb
@@ -116,7 +116,7 @@ class Tk::Iwidgets::Scrolledtext
     get('-displaychars', *index)
   end
 
-  def image_cget(index, slot)
+  def image_cget_strict(index, slot)
     case slot.to_s
     when 'text', 'label', 'show', 'data', 'file'
       _fromUTF8(tk_send_without_enc('image', 'cget', 
@@ -127,6 +127,27 @@ class Tk::Iwidgets::Scrolledtext
                                                 "-#{slot}")))
     end
   end
+  def image_cget(index, slot)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      image_cget_strict(index, slot)
+    else
+      begin
+        image_cget_strict(index, slot)
+      rescue => e
+        begin
+          if current_image_configinfo.has_key?(slot.to_s)
+            # error on known option
+            fail e
+          else
+            # unknown option
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
+    end
+  end
 
   def image_configure(index, slot, value=None)
     if slot.kind_of? Hash
diff --git a/ext/tk/lib/tkextlib/iwidgets/tabnotebook.rb b/ext/tk/lib/tkextlib/iwidgets/tabnotebook.rb
index 382604102e..dbb90e5102 100644
--- a/ext/tk/lib/tkextlib/iwidgets/tabnotebook.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/tabnotebook.rb
@@ -47,12 +47,13 @@ class Tk::Iwidgets::Tabnotebook
   end
 
   alias pagecget itemcget
+  alias pagecget_strict itemcget_strict
   alias pageconfigure itemconfigure
   alias pageconfiginfo itemconfiginfo
   alias current_pageconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/iwidgets/tabset.rb b/ext/tk/lib/tkextlib/iwidgets/tabset.rb
index 618260e8e3..300ba9dee0 100644
--- a/ext/tk/lib/tkextlib/iwidgets/tabset.rb
+++ b/ext/tk/lib/tkextlib/iwidgets/tabset.rb
@@ -42,12 +42,13 @@ class Tk::Iwidgets::Tabset
   end
 
   alias tabcget itemcget
+  alias tabcget_strict itemcget_strict
   alias tabconfigure itemconfigure
   alias tabconfiginfo itemconfiginfo
   alias current_tabconfiginfo current_itemconfiginfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 
   ####################################
 
diff --git a/ext/tk/lib/tkextlib/tcllib/getstring.rb b/ext/tk/lib/tkextlib/tcllib/getstring.rb
index bf5e54e8cf..fc5d8b26d9 100644
--- a/ext/tk/lib/tkextlib/tcllib/getstring.rb
+++ b/ext/tk/lib/tkextlib/tcllib/getstring.rb
@@ -87,7 +87,7 @@ class Tk::Tcllib::GetString_Dialog
     @variable.value
   end
 
-  def cget(slot)
+  def cget_strict(slot)
     slot = slot.to_s
     if slot == 'text'
       @text
@@ -95,6 +95,9 @@ class Tk::Tcllib::GetString_Dialog
       @keys[slot]
     end
   end
+  def cget(slot)
+    cget_strict(slot)
+  end
 
   def configure(slot, value=None)
     if slot.kind_of?(Hash)
diff --git a/ext/tk/lib/tkextlib/tcllib/swaplist.rb b/ext/tk/lib/tkextlib/tcllib/swaplist.rb
index 97de0a27c1..1c813e36da 100644
--- a/ext/tk/lib/tkextlib/tcllib/swaplist.rb
+++ b/ext/tk/lib/tkextlib/tcllib/swaplist.rb
@@ -90,7 +90,7 @@ class Tk::Tcllib::Swaplist_Dialog
   end
   alias selected value
 
-  def cget(slot)
+  def cget_strict(slot)
     slot = slot.to_s
     if slot == 'complete_list'
       @complete_list
@@ -100,6 +100,9 @@ class Tk::Tcllib::Swaplist_Dialog
       @keys[slot]
     end
   end
+  def cget(slot)
+    cget_strict(slot)
+  end
 
   def configure(slot, value=None)
     if slot.kind_of?(Hash)
diff --git a/ext/tk/lib/tkextlib/tcllib/tablelist_core.rb b/ext/tk/lib/tkextlib/tcllib/tablelist_core.rb
index a939a58331..d7a6c97210 100644
--- a/ext/tk/lib/tkextlib/tcllib/tablelist_core.rb
+++ b/ext/tk/lib/tkextlib/tcllib/tablelist_core.rb
@@ -70,6 +70,9 @@ module Tk::Tcllib::TablelistItemConfig
   def cell_cget(tagOrId, option)
     itemcget(['cell', tagOrId], option)
   end
+  def cell_cget_strict(tagOrId, option)
+    itemcget_strict(['cell', tagOrId], option)
+  end
   def cell_configure(tagOrId, slot, value=None)
     itemconfigure(['cell', tagOrId], slot, value)
   end
@@ -80,6 +83,7 @@ module Tk::Tcllib::TablelistItemConfig
     current_itemconfiginfo(['cell', tagOrId], slot)
   end
   alias cellcget cell_cget
+  alias cellcget_strict cell_cget_strict
   alias cellconfigure cell_configure
   alias cellconfiginfo cell_configinfo
   alias current_cellconfiginfo current_cell_configinfo
@@ -87,6 +91,9 @@ module Tk::Tcllib::TablelistItemConfig
   def column_cget(tagOrId, option)
     itemcget(['column', tagOrId], option)
   end
+  def column_cget_strict(tagOrId, option)
+    itemcget_strict(['column', tagOrId], option)
+  end
   def column_configure(tagOrId, slot, value=None)
     itemconfigure(['column', tagOrId], slot, value)
   end
@@ -97,6 +104,7 @@ module Tk::Tcllib::TablelistItemConfig
     current_itemconfiginfo(['column', tagOrId], slot)
   end
   alias columncget column_cget
+  alias columncget_strict column_cget_strict
   alias columnconfigure column_configure
   alias columnconfiginfo column_configinfo
   alias current_columnconfiginfo current_column_configinfo
@@ -104,6 +112,9 @@ module Tk::Tcllib::TablelistItemConfig
   def row_cget(tagOrId, option)
     itemcget(['row', tagOrId], option)
   end
+  def row_cget_strict(tagOrId, option)
+    itemcget_strict(['row', tagOrId], option)
+  end
   def row_configure(tagOrId, slot, value=None)
     itemconfigure(['row', tagOrId], slot, value)
   end
@@ -114,12 +125,13 @@ module Tk::Tcllib::TablelistItemConfig
     current_itemconfiginfo(['row', tagOrId], slot)
   end
   alias rowcget row_cget
+  alias rowcget_strict row_cget_strict
   alias rowconfigure row_configure
   alias rowconfiginfo row_configinfo
   alias current_rowconfiginfo current_row_configinfo
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 class Tk::Tcllib::Tablelist
diff --git a/ext/tk/lib/tkextlib/tile/dialog.rb b/ext/tk/lib/tkextlib/tile/dialog.rb
index b10378d7de..ef2d1fe577 100644
--- a/ext/tk/lib/tkextlib/tile/dialog.rb
+++ b/ext/tk/lib/tkextlib/tile/dialog.rb
@@ -54,9 +54,21 @@ class Tk::Tile::Dialog
     window(tk_call_without_enc('::ttk::dialog::clientframe', @path))
   end
 
+  def cget_strict(slot)
+    @keys[slot.to_s]
+  end
+  def cget(slot)
+    @keys[slot.to_s]
+  end
+=begin
   def cget(slot)
-    @keys[slot]
+    unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      cget_strict(slot)
+    else
+      cget_strict(slot) rescue nil
+    end
   end
+=end
 
   def configure(slot, value=None)
     if slot.kind_of?(Hash)
diff --git a/ext/tk/lib/tkextlib/tile/tentry.rb b/ext/tk/lib/tkextlib/tile/tentry.rb
index 4b221fcb88..0bea98dcd9 100644
--- a/ext/tk/lib/tkextlib/tile/tentry.rb
+++ b/ext/tk/lib/tkextlib/tile/tentry.rb
@@ -27,6 +27,11 @@ class Tk::Tile::TEntry < Tk::Entry
   WidgetClassName = 'TEntry'.freeze
   WidgetClassNames[WidgetClassName] = self
 
+  def __optkey_aliases
+    {:vcmd=>:validatecommand, :invcmd=>:invalidcommand}
+  end
+  private :__optkey_aliases
+
   def __boolval_optkeys
     super() << 'exportselection'
   end
diff --git a/ext/tk/lib/tkextlib/tile/tnotebook.rb b/ext/tk/lib/tkextlib/tile/tnotebook.rb
index 075059d5cc..4d65e363da 100644
--- a/ext/tk/lib/tkextlib/tile/tnotebook.rb
+++ b/ext/tk/lib/tkextlib/tile/tnotebook.rb
@@ -41,13 +41,35 @@ class Tk::Tile::TNotebook < TkWindow
   private :__item_methodcall_optkeys
 
   #alias tabcget itemcget
+  #alias tabcget_strict itemcget_strict
   alias tabconfigure itemconfigure
   alias tabconfiginfo itemconfiginfo
   alias current_tabconfiginfo current_itemconfiginfo
 
-  def tabcget(tagOrId, option)
+  def tabcget_strict(tagOrId, option)
     tabconfigure(tagOrId, option)[-1]
   end
+  def tabcget(tagOrId, option)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      tabcget_strict(tagOrId, option)
+    else
+      begin
+        tabcget_strict(tagOrId, option)
+      rescue => e
+        begin
+          if current_tabconfiginfo(tagOrId).has_key?(option.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
+    end
+  end
   ################################
 
   include Tk::Tile::TileWidget
diff --git a/ext/tk/lib/tkextlib/tile/tpaned.rb b/ext/tk/lib/tkextlib/tile/tpaned.rb
index f24b12e92e..d96ff43973 100644
--- a/ext/tk/lib/tkextlib/tile/tpaned.rb
+++ b/ext/tk/lib/tkextlib/tile/tpaned.rb
@@ -66,10 +66,33 @@ class Tk::Tile::TPaned < TkWindow
     self
   end
 
-  def panecget(pane, slot)
+  def panecget_strict(pane, slot)
     pane = _epath(pane)
     tk_tcl2ruby(tk_send_without_enc('pane', pane, "-#{slot}"))
   end
+  alias pane_cget_strict panecget_strict
+
+  def panecget(pane, slot)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      panecget_strict(pane, slot)
+    else
+      begin
+        panecget_strict(pane, slot)
+      rescue => e
+        begin
+          if current_paneconfiginfo(pane).has_key?(slot.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
+    end
+  end
   alias pane_cget panecget
 
   def paneconfigure(pane, key, value=nil)
diff --git a/ext/tk/lib/tkextlib/tile/treeview.rb b/ext/tk/lib/tkextlib/tile/treeview.rb
index 7f31b9c233..c978a1a07b 100644
--- a/ext/tk/lib/tkextlib/tile/treeview.rb
+++ b/ext/tk/lib/tkextlib/tile/treeview.rb
@@ -33,6 +33,12 @@ module Tk::Tile::TreeviewConfig
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__tile_specific_item_optkeys(tagid(tagOrId)).join('|')})$/
             begin
@@ -198,6 +204,12 @@ module Tk::Tile::TreeviewConfig
       else
         if slot
           slot = slot.to_s
+
+          alias_name, real_name = __item_optkey_aliases(tagid(tagOrId)).find{|k, v| k.to_s == slot}
+          if real_name
+            slot = real_name.to_s
+          end
+
           case slot
           when /^(#{__tile_specific_item_optkeys(tagid(tagOrId)).join('|')})$/
             begin
@@ -508,17 +520,21 @@ module Tk::Tile::TreeviewConfig
   end
 
   alias __itemcget itemcget
+  alias __itemcget_strict itemcget_strict
   alias __itemconfigure itemconfigure
   alias __itemconfiginfo itemconfiginfo
   alias __current_itemconfiginfo current_itemconfiginfo
 
-  private :__itemcget, :__itemconfigure
-  private :__itemconfiginfo, :__current_itemconfiginfo
+  private :__itemcget, :__itemcget_strict
+  private :__itemconfigure, :__itemconfiginfo, :__current_itemconfiginfo
 
   # Treeview Item
   def itemcget(tagOrId, option)
     __itemcget([:item, tagOrId], option)
   end
+  def itemcget_strict(tagOrId, option)
+    __itemcget_strict([:item, tagOrId], option)
+  end
   def itemconfigure(tagOrId, slot, value=None)
     __itemconfigure([:item, tagOrId], slot, value)
   end
@@ -533,6 +549,9 @@ module Tk::Tile::TreeviewConfig
   def columncget(tagOrId, option)
     __itemcget([:column, tagOrId], option)
   end
+  def columncget_strict(tagOrId, option)
+    __itemcget_strict([:column, tagOrId], option)
+  end
   def columnconfigure(tagOrId, slot, value=None)
     __itemconfigure([:column, tagOrId], slot, value)
   end
@@ -543,12 +562,13 @@ module Tk::Tile::TreeviewConfig
     __current_itemconfiginfo([:column, tagOrId], slot)
   end
   alias column_cget columncget
+  alias column_cget_strict columncget_strict
   alias column_configure columnconfigure
   alias column_configinfo columnconfiginfo
   alias current_column_configinfo current_columnconfiginfo
 
   # Treeview Heading
-  def headingcget(tagOrId, option)
+  def headingcget_strict(tagOrId, option)
     if __tile_specific_item_optkeys([:heading, tagOrId]).index(option.to_s)
       begin
         # On tile-0.7.{2-8}, 'state' options has no '-' at its head.
@@ -558,7 +578,28 @@ module Tk::Tile::TreeviewConfig
         tk_call(*(__item_cget_cmd([:heading, tagOrId]) << "-#{option}"))
       end
     else
-      __itemcget([:heading, tagOrId], option)
+      __itemcget_strict([:heading, tagOrId], option)
+    end
+  end
+  def headingcget(tagOrId, option)
+    unless TkItemConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
+      headingcget_strict(tagOrId, option)
+    else
+      begin
+        headingcget_strict(tagOrId, option)
+      rescue => e
+        begin
+          if current_headingconfiginfo(tagOrId).has_key?(option.to_s)
+            # not tag error & option is known -> error on known option
+            fail e
+          else
+            # not tag error & option is unknown
+            nil
+          end
+        rescue
+          fail e  # tag error
+        end
+      end
     end
   end
   def headingconfigure(tagOrId, slot, value=None)
@@ -590,6 +631,7 @@ module Tk::Tile::TreeviewConfig
     __current_itemconfiginfo([:heading, tagOrId], slot)
   end
   alias heading_cget headingcget
+  alias heading_cget_strict headingcget_strict
   alias heading_configure headingconfigure
   alias heading_configinfo headingconfiginfo
   alias current_heading_configinfo current_headingconfiginfo
@@ -598,6 +640,9 @@ module Tk::Tile::TreeviewConfig
   def tagcget(tagOrId, option)
     __itemcget([:tag, tagOrId], option)
   end
+  def tagcget_strict(tagOrId, option)
+    __itemcget_strict([:tag, tagOrId], option)
+  end
   def tagconfigure(tagOrId, slot, value=None)
     __itemconfigure([:tag, tagOrId], slot, value)
   end
@@ -608,6 +653,7 @@ module Tk::Tile::TreeviewConfig
     __current_itemconfiginfo([:tag, tagOrId], slot)
   end
   alias tag_cget tagcget
+  alias tag_cget_strict tagcget_strict
   alias tag_configure tagconfigure
   alias tag_configinfo tagconfiginfo
   alias current_tag_configinfo current_tagconfiginfo
@@ -694,6 +740,9 @@ class Tk::Tile::Treeview::Item < TkObject
   def cget(option)
     @t.itemcget(@id, option)
   end
+  def cget_strict(option)
+    @t.itemcget_strict(@id, option)
+  end
 
   def configure(key, value=None)
     @t.itemconfigure(@id, key, value)
@@ -933,6 +982,9 @@ class Tk::Tile::Treeview::Tag < TkObject
   def cget(option)
     @t.tagcget(@id, option)
   end
+  def cget_strict(option)
+    @t.tagcget_strict(@id, option)
+  end
 
   def configure(key, value=None)
     @t.tagconfigure(@id, key, value)
diff --git a/ext/tk/lib/tkextlib/tktable/tktable.rb b/ext/tk/lib/tkextlib/tktable/tktable.rb
index b5bf4ea6c3..f6cf24b40f 100644
--- a/ext/tk/lib/tkextlib/tktable/tktable.rb
+++ b/ext/tk/lib/tkextlib/tktable/tktable.rb
@@ -77,6 +77,9 @@ module Tk::TkTable::ConfigMethod
   def tag_cget(tagOrId, option)
     itemcget(['tag', tagid(tagOrId)], option)
   end
+  def tag_cget_strict(tagOrId, option)
+    itemcget_strict(['tag', tagid(tagOrId)], option)
+  end
   def tag_configure(tagOrId, slot, value=None)
     itemconfigure(['tag', tagid(tagOrId)], slot, value)
   end
@@ -90,6 +93,9 @@ module Tk::TkTable::ConfigMethod
   def window_cget(tagOrId, option)
     itemcget(['window', tagid(tagOrId)], option)
   end
+  def window_cget_strict(tagOrId, option)
+    itemcget_strict(['window', tagid(tagOrId)], option)
+  end
   def window_configure(tagOrId, slot, value=None)
     if slot == :window || slot == 'window'
       value = _epath(value)
@@ -108,8 +114,8 @@ module Tk::TkTable::ConfigMethod
     current_itemconfiginfo(['window', tagid(tagOrId)], slot)
   end
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 #####################################################
@@ -194,6 +200,9 @@ class Tk::TkTable::CellTag
   def cget(key)
     @t.tag_cget(@id, key)
   end
+  def cget_strict(key)
+    @t.tag_cget_strict(@id, key)
+  end
   def configure(key, val=None)
     @t.tag_configure(@id, key, val)
   end
diff --git a/ext/tk/lib/tkextlib/treectrl/tktreectrl.rb b/ext/tk/lib/tkextlib/treectrl/tktreectrl.rb
index 5e86a19406..e10e6e299e 100644
--- a/ext/tk/lib/tkextlib/treectrl/tktreectrl.rb
+++ b/ext/tk/lib/tkextlib/treectrl/tktreectrl.rb
@@ -417,6 +417,9 @@ module Tk::TreeCtrl::ConfigMethod
   def column_cget(tagOrId, option)
     itemcget(['column', tagOrId], option)
   end
+  def column_cget_strict(tagOrId, option)
+    itemcget_strict(['column', tagOrId], option)
+  end
   def column_configure(tagOrId, slot, value=None)
     itemconfigure(['column', tagOrId], slot, value)
   end
@@ -430,6 +433,9 @@ module Tk::TreeCtrl::ConfigMethod
   def column_dragcget(option)
     itemcget(['column', 'drag'], option)
   end
+  def column_dragcget_strict(option)
+    itemcget_strict(['column', 'drag'], option)
+  end
   def column_dragconfigure(slot, value=None)
     itemconfigure(['column', 'drag'], slot, value)
   end
@@ -443,6 +449,9 @@ module Tk::TreeCtrl::ConfigMethod
   def debug_cget(option)
     itemcget('debug', option)
   end
+  def debug_cget_strict(option)
+    itemcget_strict('debug', option)
+  end
   def debug_configure(slot, value=None)
     itemconfigure('debug', slot, value)
   end
@@ -456,6 +465,9 @@ module Tk::TreeCtrl::ConfigMethod
   def dragimage_cget(option)
     itemcget('dragimage', option)
   end
+  def dragimage_cget_strict(option)
+    itemcget_strict('dragimage', option)
+  end
   def dragimage_configure(slot, value=None)
     itemconfigure('dragimage', slot, value)
   end
@@ -469,6 +481,9 @@ module Tk::TreeCtrl::ConfigMethod
   def element_cget(tagOrId, option)
     itemcget(['element', tagOrId], option)
   end
+  def element_cget_strict(tagOrId, option)
+    itemcget_strict(['element', tagOrId], option)
+  end
   def element_configure(tagOrId, slot, value=None)
     itemconfigure(['element', tagOrId], slot, value)
   end
@@ -482,6 +497,9 @@ module Tk::TreeCtrl::ConfigMethod
   def item_cget(tagOrId, option)
     itemcget(['item', tagOrId], option)
   end
+  def item_cget_strict(tagOrId, option)
+    itemcget_strict(['item', tagOrId], option)
+  end
   def item_configure(tagOrId, slot, value=None)
     itemconfigure(['item', tagOrId], slot, value)
   end
@@ -495,6 +513,9 @@ module Tk::TreeCtrl::ConfigMethod
   def item_element_cget(item, column, elem, option)
     itemcget([['item', 'element'], [item, column, elem]], option)
   end
+  def item_element_cget_strict(item, column, elem, option)
+    itemcget_strict([['item', 'element'], [item, column, elem]], option)
+  end
   def item_element_configure(item, column, elem, slot, value=None)
     itemconfigure([['item', 'element'], [item, column, elem]], slot, value)
   end
@@ -508,6 +529,9 @@ module Tk::TreeCtrl::ConfigMethod
   def marquee_cget(option)
     itemcget('marquee', option)
   end
+  def marquee_cget_strict(option)
+    itemcget_strict('marquee', option)
+  end
   def marquee_configure(slot, value=None)
     itemconfigure('marquee', slot, value)
   end
@@ -523,6 +547,17 @@ module Tk::TreeCtrl::ConfigMethod
     # "notify" doesn't have cget subcommand.
     current_itemconfiginfo(['notify', [win, pattern]])[option.to_s]
   end
+  def notify_cget_strict(win, pattern, option)
+    pattern = "<#{pattern}>"
+    # "notify" doesn't have cget subcommand.
+    info = current_itemconfiginfo(['notify', [win, pattern]])
+    option = option.to_s
+    unless info.has_key?(option)
+      fail RuntimeError, "unknown option \"#{option}\""
+    else
+      info[option]
+    end
+  end
   def notify_configure(win, pattern, slot, value=None)
     pattern = "<#{pattern}>"
     itemconfigure(['notify', [win, pattern]], slot, value)
@@ -539,6 +574,9 @@ module Tk::TreeCtrl::ConfigMethod
   def style_cget(tagOrId, option)
     itemcget(['style', tagOrId], option)
   end
+  def style_cget_strict(tagOrId, option)
+    itemcget_strict(['style', tagOrId], option)
+  end
   def style_configure(tagOrId, slot, value=None)
     itemconfigure(['style', tagOrId], slot, value)
   end
@@ -549,8 +587,8 @@ module Tk::TreeCtrl::ConfigMethod
     current_itemconfiginfo(['style', tagOrId], slot)
   end
 
-  private :itemcget, :itemconfigure
-  private :itemconfiginfo, :current_itemconfiginfo
+  private :itemcget, :itemcget_strict
+  private :itemconfigure, :itemconfiginfo, :current_itemconfiginfo
 end
 
 ##############################################
@@ -1706,6 +1744,9 @@ class Tk::TreeCtrl::Column < TkObject
   def cget(opt)
     @tree.column_cget(@tree.column_index(@id), opt)
   end
+  def cget_strict(opt)
+    @tree.column_cget_strict(@tree.column_index(@id), opt)
+  end
 
   def configure(*args)
     @tree.column_configure(@tree.column_index(@id), *args)
@@ -1806,6 +1847,9 @@ class Tk::TreeCtrl::Element < TkObject
   def cget(opt)
     @tree.element_cget(@id, opt)
   end
+  def cget_strict(opt)
+    @tree.element_cget_strict(@id, opt)
+  end
 
   def configure(*args)
     @tree.element_configure(@id, *args)
@@ -1937,6 +1981,9 @@ class Tk::TreeCtrl::Item < TkObject
   def cget(opt)
     @tree.item_cget(@id, opt)
   end
+  def cget_strict(opt)
+    @tree.item_cget_strict(@id, opt)
+  end
 
   def configure(*args)
     @tree.item_configure(@id, *args)
@@ -1970,6 +2017,9 @@ class Tk::TreeCtrl::Item < TkObject
   def element_cget(opt)
     @tree.item_element_cget(@id, opt)
   end
+  def element_cget_strict(opt)
+    @tree.item_element_cget_strict(@id, opt)
+  end
 
   def element_configure(*args)
     @tree.item_element_configure(@id, *args)
@@ -2221,6 +2271,9 @@ class Tk::TreeCtrl::Style < TkObject
   def cget(opt)
     @tree.style_cget(@id, opt)
   end
+  def cget_strict(opt)
+    @tree.style_cget_strict(@id, opt)
+  end
 
   def configure(*args)
     @tree.style_configure(@id, *args)
diff --git a/ext/tk/lib/tkextlib/version.rb b/ext/tk/lib/tkextlib/version.rb
index f437dea7fd..434ed11a2e 100644
--- a/ext/tk/lib/tkextlib/version.rb
+++ b/ext/tk/lib/tkextlib/version.rb
@@ -2,5 +2,5 @@
 # release date of tkextlib
 #
 module Tk
-  Tkextlib_RELEASE_DATE = '2008-05-14'.freeze
+  Tkextlib_RELEASE_DATE = '2008-05-23'.freeze
 end
diff --git a/ext/tk/lib/tkextlib/vu/pie.rb b/ext/tk/lib/tkextlib/vu/pie.rb
index 1975803db1..c1fb6857bf 100644
--- a/ext/tk/lib/tkextlib/vu/pie.rb
+++ b/ext/tk/lib/tkextlib/vu/pie.rb
@@ -177,6 +177,10 @@ class Tk::Vu::PieSlice
     @pie.itemcget(@id, slot)
   end
 
+  def cget_strict(slot)
+    @pie.itemcget_strict(@id, slot)
+  end
+
   def configure(*args)
     @pie.itemconfigure(@id, *args)
     self