wx: Fix crash when garbage collect event handlers (debugger caused seg fault)

wxStyledTextCtrl had no wrapper class so, because it was not detected
that it had virtual destructors, thus references to it was not cleaned
up on destruction. When a process dies and wx cleans up the event handlers
access was made to the deleted object and caused a seg fault.

Added a testcase which I thought could provoke the bug but didn't.

3 files changed, 82 insertions, 36 deletions

diff --git a/lib/wx/test/wx_basic_SUITE.erl b/lib/wx/test/wx_basic_SUITE.erl
index d55a037599..c5b0927bf3 100644
--- a/lib/wx/test/wx_basic_SUITE.erl
+++ b/lib/wx/test/wx_basic_SUITE.erl
@@ -324,7 +324,18 @@ data_types(_Config) ->
 wx_object(TestInfo) when is_atom(TestInfo) -> wx_test_lib:tc_info(TestInfo);
 wx_object(Config) ->
     wx:new(),
-    Frame = ?mt(wxFrame, wx_obj_test:start([])),
+    Me = self(),
+    Init = fun() ->
+		   Frame = wxFrame:new(wx:null(), ?wxID_ANY, "Test wx_object", [{size, {500, 400}}]),
+		   Sz = wxBoxSizer:new(?wxHORIZONTAL),
+		   Panel = wxPanel:new(Frame),
+		   wxSizer:add(Sz, Panel, [{flag, ?wxEXPAND}, {proportion, 1}]),
+		   wxPanel:connect(Panel, size, [{skip, true}]),
+		   wxPanel:connect(Panel, paint, [callback, {userData, Me}]),
+		   wxWindow:show(Frame),
+		   {Frame, {Frame, Panel}}
+	   end,
+    Frame = ?mt(wxFrame, wx_obj_test:start([{init, Init}])),
     timer:sleep(500),
     ?m(ok, check_events(flush())),
 
diff --git a/lib/wx/test/wx_event_SUITE.erl b/lib/wx/test/wx_event_SUITE.erl
index 6a9f19ad51..bbb5294d08 100644
--- a/lib/wx/test/wx_event_SUITE.erl
+++ b/lib/wx/test/wx_event_SUITE.erl
@@ -484,6 +484,7 @@ callback_clean(Config) ->
     %% timer:sleep(infinity),
     %% ok.
 
+
 white_box_check_event_handlers() ->
     {_,_,Server,_} = wx:get_env(),
     {status, _, _, [Env, _, _, _, Data]} = sys:get_status(Server),
@@ -495,3 +496,35 @@ white_box_check_event_handlers() ->
      gb_trees:to_list(CBs),
      [Funs || Funs = {Id, {Fun,_}} <- Env, is_integer(Id), is_function(Fun)]
     }.
+
+handler_clean(TestInfo) when is_atom(TestInfo) ->
+    wx_test_lib:tc_info(TestInfo);
+handler_clean(_Config) ->
+    wx:new(),
+    Init = fun() -> create_window() end,
+    Frame1 = wx_obj_test:start([{init, Init}]),
+    ?mt(wxFrame, Frame1),
+    wxWindow:show(Frame1),
+    ?m([_|_], lists:sort(wx_test_lib:flush())),
+    ?m({stop,_}, wx_obj_test:stop(Frame1, fun(_) -> normal end)),
+    ?m([{terminate,normal}], lists:sort(wx_test_lib:flush())),
+
+    Frame2 = wx_obj_test:start([{init, Init}]),
+    wxWindow:show(Frame2),
+    ?m([_|_], lists:sort(wx_test_lib:flush())),
+    ?m({stop,_}, wx_obj_test:stop(Frame2, fun(_) -> wxWindow:destroy(Frame2), normal end)),
+    ?m([{terminate,normal}], lists:sort(wx_test_lib:flush())),
+    timer:sleep(104),
+    ?m({[],[],[]}, white_box_check_event_handlers()),
+    ?m(ok, wx:destroy()),
+    ok.
+
+create_window() ->
+    Frame = wxFrame:new(wx:null(), ?wxID_ANY, "Test wx_object", [{size, {500, 400}}]),
+    Sz = wxBoxSizer:new(?wxHORIZONTAL),
+    Panel = wxPanel:new(Frame),
+    wxSizer:add(Sz, Panel, [{flag, ?wxEXPAND}, {proportion, 1}]),
+    wxWindow:connect(Frame, show),
+    %% wxPanel:connect(Panel, paint, [callback, {userData, foobar}]),
+    wxWindow:connect(Panel, size, [callback]),
+    {Frame, {Frame, Panel}}.
diff --git a/lib/wx/test/wx_obj_test.erl b/lib/wx/test/wx_obj_test.erl
index b4d7640c7e..f47f2fbc46 100644
--- a/lib/wx/test/wx_obj_test.erl
+++ b/lib/wx/test/wx_obj_test.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2011. All Rights Reserved.
+%% Copyright Ericsson AB 2011-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -18,69 +18,71 @@
 -module(wx_obj_test).
 -include_lib("wx/include/wx.hrl").
 
--export([start/1]).
+-export([start/1, stop/2]).
 
 %% wx_object callbacks
 -export([init/1, handle_info/2, terminate/2, code_change/3, handle_call/3,
 	 handle_sync_event/3, handle_event/2, handle_cast/2]).
 
--record(state, {frame, panel, opts}).
+-record(state, {parent, opts, user_state}).
 
 start(Opts) ->
-    wx_object:start_link(?MODULE, [{parent, self()}, Opts], []).
+    wx_object:start_link(?MODULE, [{parent, self()}| Opts], []).
+
+stop(Object, Fun) ->
+    wx_object:call(Object, {stop, Fun}).
 
 init(Opts) ->
-    put(parent_pid, proplists:get_value(parent, Opts)),
-    Frame = wxFrame:new(wx:null(), ?wxID_ANY, "Test wx_object", [{size, {500, 400}}]),
-    Sz = wxBoxSizer:new(?wxHORIZONTAL),
-    Panel = wxPanel:new(Frame),
-    wxSizer:add(Sz, Panel, [{flag, ?wxEXPAND}, {proportion, 1}]),
-    wxPanel:connect(Panel, size, [{skip, true}]),
-    wxPanel:connect(Panel, paint, [callback, {userData, proplists:get_value(parent, Opts)}]),
-    wxWindow:show(Frame),
-    {Frame, #state{frame=Frame, panel=Panel, opts=Opts}}.
+    Parent = proplists:get_value(parent, Opts),
+    put(parent_pid, Parent),
+    Init = proplists:get_value(init, Opts),
+    {Obj, UserState} = Init(),
+    {Obj, #state{parent=Parent, opts=Opts, user_state=UserState}}.
 
-handle_sync_event(Event = #wx{obj=Panel}, WxEvent, #state{opts=Opts}) ->
-    DC=wxPaintDC:new(Panel),  %% We must create & destroy paintDC, or call wxEvent:skip(WxEvent))
-    wxPaintDC:destroy(DC),    %% in sync_event. Otherwise wx on windows keeps sending the events.
-    Pid = proplists:get_value(parent, Opts),
-    true = is_pid(Pid),
-    Pid ! {sync_event, Event, WxEvent},
+handle_sync_event(Event = #wx{obj=Panel, event=#wxPaint{}},
+		  WxEvent, #state{parent=Parent, user_state=US, opts=Opts}) ->
+    case proplists:get_value(redraw, Opts) of
+	undefined ->
+	    DC=wxPaintDC:new(Panel),  %% We must create & destroy paintDC, or call wxEvent:skip(WxEvent))
+	    wxPaintDC:destroy(DC),    %% in sync_event. Otherwise wx on windows keeps sending the events.
+	    Parent ! {sync_event, Event, WxEvent};
+	Redraw ->
+	    Redraw(Event, WxEvent, US)
+    end,
+    ok;
+handle_sync_event(Event, WxEvent, #state{parent=Parent}) ->
+    Parent ! {sync_event, Event, WxEvent},
     ok.
 
-handle_event(Event, State = #state{opts=Opts}) ->
-    Pid = proplists:get_value(parent, Opts),
-    Pid ! {event, Event},
+handle_event(Event, State = #state{parent=Parent}) ->
+    Parent ! {event, Event},
     {noreply, State}.
 
-handle_call(What, From, State) when is_function(What) ->
-    Result = What(State),
+handle_call(What, From, State = #state{user_state=US}) when is_function(What) ->
+    Result = What(US),
     {reply, {call, Result, From}, State};
+handle_call({stop, Fun}, From, State = #state{user_state=US}) ->
+    {stop, Fun(US), {stop, From}, State};
 handle_call(What, From, State) ->
     {reply, {call, What, From}, State}.
 
-handle_cast(What, State = #state{opts=Opts})  when is_function(What) ->
-    Result = What(State),
-    Pid = proplists:get_value(parent, Opts),
+handle_cast(What, State = #state{parent=Pid, user_state=US})  when is_function(What) ->
+    Result = What(US),
     Pid ! {cast, Result},
     {noreply, State};
 
-handle_cast(What, State = #state{opts=Opts}) ->
-    Pid = proplists:get_value(parent, Opts),
+handle_cast(What, State = #state{parent=Pid}) ->
     Pid ! {cast, What},
     {noreply, State}.
 
-handle_info(What, State = #state{opts=Opts}) ->
-    Pid = proplists:get_value(parent, Opts),
+handle_info(What, State = #state{parent=Pid}) ->
     Pid ! {info, What},
     {noreply, State}.
 
-terminate(What, #state{opts=Opts}) ->
-    Pid = proplists:get_value(parent, Opts),
+terminate(What, #state{parent=Pid}) ->
     Pid ! {terminate, What},
     ok.
 
-code_change(Ver1, Ver2, State = #state{opts=Opts}) ->
-    Pid = proplists:get_value(parent, Opts),
+code_change(Ver1, Ver2, State = #state{parent=Pid}) ->
     Pid ! {code_change, Ver1, Ver2},
     State.