]> git.saurik.com Git - wxWidgets.git/blobdiff - src/msw/dde.cpp
Fix another off-by-1 bug in wxMBConv::ToWChar().
[wxWidgets.git] / src / msw / dde.cpp
index 606abdac8bc16ce8d2253a0fc8651a05cf9962d4..330ffa077d0f28cc912b2e7cdae838f25da3bd62 100644 (file)
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        msw/dde.cpp
+// Name:        src/msw/dde.cpp
 // Purpose:     DDE classes
 // Author:      Julian Smart
 // Modified by:
 // headers
 // ----------------------------------------------------------------------------
 
-#ifdef __GNUG__
-    #pragma implementation "dde.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifndef WX_PRECOMP
     #include "wx/utils.h"
     #include "wx/app.h"
+    #include "wx/hashmap.h"
+    #include "wx/module.h"
 #endif
 
-#include "wx/module.h"
 #include "wx/dde.h"
 #include "wx/intl.h"
-
+#include "wx/buffer.h"
+#include "wx/strconv.h"
 
 #include "wx/msw/private.h"
 
 #include <string.h>
-#include <windows.h>
 #include <ddeml.h>
 
-#ifdef __GNUWIN32_OLD__
-    #include "wx/msw/gnuwin32/extra.h"
-#endif
-
-// some compilers headers don't define this one (mingw32)
-#ifndef DMLERR_NO_ERROR
-    #define DMLERR_NO_ERROR (0)
-
-    // this one is also missing from some mingw32 headers, but there is no way
-    // to test for it (I know of) - the test for DMLERR_NO_ERROR works for me,
-    // but is surely not the right thing to do
-    extern "C"
-    HDDEDATA STDCALL DdeClientTransaction(LPBYTE pData,
-                                          DWORD cbData,
-                                          HCONV hConv,
-                                          HSZ hszItem,
-                                          UINT wFmt,
-                                          UINT wType,
-                                          DWORD dwTimeout,
-                                          LPDWORD pdwResult);
-#endif // no DMLERR_NO_ERROR
-
 // ----------------------------------------------------------------------------
 // macros and constants
 // ----------------------------------------------------------------------------
@@ -113,6 +88,7 @@ static HSZ DDEGetAtom(const wxString& string);
 // string handles
 static HSZ DDEAtomFromString(const wxString& s);
 static wxString DDEStringFromAtom(HSZ hsz);
+static void DDEFreeString(HSZ hsz);
 
 // error handling
 static wxString DDEGetErrorMsg(UINT error);
@@ -122,15 +98,17 @@ static void DDELogError(const wxString& s, UINT error = DMLERR_NO_ERROR);
 // global variables
 // ----------------------------------------------------------------------------
 
+WX_DECLARE_STRING_HASH_MAP( HSZ, wxAtomMap );
+
 static DWORD DDEIdInst = 0L;
 static wxDDEConnection *DDECurrentlyConnecting = NULL;
-static wxList wxAtomTable(wxKEY_STRING);
+static wxAtomMap wxAtomTable;
 
 #include "wx/listimpl.cpp"
 
-WX_DEFINE_LIST(wxDDEClientList);
-WX_DEFINE_LIST(wxDDEServerList);
-WX_DEFINE_LIST(wxDDEConnectionList);
+WX_DEFINE_LIST(wxDDEClientList)
+WX_DEFINE_LIST(wxDDEServerList)
+WX_DEFINE_LIST(wxDDEConnectionList)
 
 static wxDDEClientList wxDDEClientObjects;
 static wxDDEServerList wxDDEServerObjects;
@@ -182,7 +160,7 @@ extern void wxDDEInitialize()
         UINT rc = DdeInitialize(&DDEIdInst, callback, APPCLASS_STANDARD, 0L);
         if ( rc != DMLERR_NO_ERROR )
         {
-            DDELogError(_T("Failed to initialize DDE"), rc);
+            DDELogError(wxT("Failed to initialize DDE"), rc);
         }
         else
         {
@@ -193,15 +171,12 @@ extern void wxDDEInitialize()
 
 void wxDDECleanUp()
 {
-    wxDDEClientObjects.DeleteContents(true);
-    wxDDEClientObjects.Clear();
-    wxDDEClientObjects.DeleteContents(false);
-
-    wxDDEServerObjects.DeleteContents(true);
-    wxDDEServerObjects.Clear();
-    wxDDEServerObjects.DeleteContents(false);
+    // deleting them later won't work as DDE won't be initialized any more
+    wxASSERT_MSG( wxDDEServerObjects.empty() &&
+                    wxDDEClientObjects.empty(),
+                    wxT("all DDE objects should be deleted by now") );
 
-    wxAtomTable.Clear();
+    wxAtomTable.clear();
 
     if ( DDEIdInst != 0 )
     {
@@ -217,7 +192,7 @@ void wxDDECleanUp()
 // Global find connection
 static wxDDEConnection *DDEFindConnection(HCONV hConv)
 {
-    wxDDEServerList::Node *serverNode = wxDDEServerObjects.GetFirst();
+    wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
     wxDDEConnection *found = NULL;
     while (serverNode && !found)
     {
@@ -231,7 +206,7 @@ static wxDDEConnection *DDEFindConnection(HCONV hConv)
         return found;
     }
 
-    wxDDEClientList::Node *clientNode = wxDDEClientObjects.GetFirst();
+    wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
     while (clientNode && !found)
     {
         wxDDEClient *object = clientNode->GetData();
@@ -244,7 +219,7 @@ static wxDDEConnection *DDEFindConnection(HCONV hConv)
 // Global delete connection
 static void DDEDeleteConnection(HCONV hConv)
 {
-    wxDDEServerList::Node *serverNode = wxDDEServerObjects.GetFirst();
+    wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
     bool found = false;
     while (serverNode && !found)
     {
@@ -257,7 +232,7 @@ static void DDEDeleteConnection(HCONV hConv)
         return;
     }
 
-    wxDDEClientList::Node *clientNode = wxDDEClientObjects.GetFirst();
+    wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
     while (clientNode && !found)
     {
         wxDDEClient *object = clientNode->GetData();
@@ -269,7 +244,7 @@ static void DDEDeleteConnection(HCONV hConv)
 // Find a server from a service name
 static wxDDEServer *DDEFindServer(const wxString& s)
 {
-    wxDDEServerList::Node *node = wxDDEServerObjects.GetFirst();
+    wxDDEServerList::compatibility_iterator node = wxDDEServerObjects.GetFirst();
     wxDDEServer *found = NULL;
     while (node && !found)
     {
@@ -303,36 +278,55 @@ bool wxDDEServer::Create(const wxString& server)
 {
     m_serviceName = server;
 
-    if ( !DdeNameService(DDEIdInst, DDEAtomFromString(server), (HSZ)NULL, DNS_REGISTER) )
-    {
-        DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
-                                     server.c_str()));
+    HSZ hsz = DDEAtomFromString(server);
 
+    if ( !hsz )
+    {
         return false;
     }
 
-    return true;
+
+    bool success = (DdeNameService(DDEIdInst, hsz, (HSZ) NULL, DNS_REGISTER)
+        != NULL);
+
+    if (!success)
+    {
+        DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
+            server.c_str()));
+    }
+
+    DDEFreeString(hsz);
+
+    return success;
 }
 
 wxDDEServer::~wxDDEServer()
 {
-    if ( !!m_serviceName )
+    if ( !m_serviceName.empty() )
     {
-        if ( !DdeNameService(DDEIdInst, DDEAtomFromString(m_serviceName),
-                             (HSZ)NULL, DNS_UNREGISTER) )
+        HSZ hsz = DDEAtomFromString(m_serviceName);
+
+        if (hsz)
         {
-            DDELogError(wxString::Format(_("Failed to unregister DDE server '%s'"),
-                                         m_serviceName.c_str()));
+            if ( !DdeNameService(DDEIdInst, hsz,
+                (HSZ) NULL, DNS_UNREGISTER) )
+            {
+                DDELogError(wxString::Format(
+                    _("Failed to unregister DDE server '%s'"),
+                    m_serviceName.c_str()));
+            }
+
+            DDEFreeString(hsz);
         }
     }
 
     wxDDEServerObjects.DeleteObject(this);
 
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     while (node)
     {
         wxDDEConnection *connection = node->GetData();
-        wxDDEConnectionList::Node *next = node->GetNext();
+        wxDDEConnectionList::compatibility_iterator next = node->GetNext();
         connection->SetConnected(false);
         connection->OnDisconnect(); // May delete the node implicitly
         node = next;
@@ -343,7 +337,7 @@ wxDDEServer::~wxDDEServer()
     while (node)
     {
         wxDDEConnection *connection = node->GetData();
-        wxDDEConnectionList::Node *next = node->GetNext();
+        wxDDEConnectionList::compatibility_iterator next = node->GetNext();
         delete connection;
         node = next;
     }
@@ -356,7 +350,7 @@ wxConnectionBase *wxDDEServer::OnAcceptConnection(const wxString& /* topic */)
 
 wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 {
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     wxDDEConnection *found = NULL;
     while (node && !found)
     {
@@ -371,22 +365,21 @@ wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 // Only delete the entry in the map, not the actual connection
 bool wxDDEServer::DeleteConnection(WXHCONV conv)
 {
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
-    bool found = false;
-    while (node && !found)
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
+    while (node)
     {
         wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
         {
-            found = true;
-            delete node;
+            m_connections.Erase(node);
+            return true;
         }
         else
         {
             node = node->GetNext();
         }
     }
-    return found;
+    return false;
 }
 
 // ----------------------------------------------------------------------------
@@ -403,7 +396,7 @@ wxDDEClient::wxDDEClient()
 wxDDEClient::~wxDDEClient()
 {
     wxDDEClientObjects.DeleteObject(this);
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     while (node)
     {
         wxDDEConnection *connection = node->GetData();
@@ -421,12 +414,35 @@ wxConnectionBase *wxDDEClient::MakeConnection(const wxString& WXUNUSED(host),
                                               const wxString& server,
                                               const wxString& topic)
 {
-    HCONV hConv = DdeConnect(DDEIdInst, DDEAtomFromString(server), DDEAtomFromString(topic),
-                             (PCONVCONTEXT)NULL);
+    HSZ hszServer = DDEAtomFromString(server);
+
+    if ( !hszServer )
+    {
+        return NULL;
+    }
+
+
+    HSZ hszTopic = DDEAtomFromString(topic);
+
+    if ( !hszTopic )
+    {
+        DDEFreeString(hszServer);
+        return NULL;
+    }
+
+
+    HCONV hConv = ::DdeConnect(DDEIdInst, hszServer, hszTopic,
+        (PCONVCONTEXT) NULL);
+
+    DDEFreeString(hszServer);
+    DDEFreeString(hszTopic);
+
+
     if ( !hConv )
     {
-        DDELogError(wxString::Format(_("Failed to create connection to server '%s' on topic '%s'"),
-                                     server.c_str(), topic.c_str()));
+        DDELogError( wxString::Format(
+            _("Failed to create connection to server '%s' on topic '%s'"),
+            server.c_str(), topic.c_str()) );
     }
     else
     {
@@ -441,7 +457,7 @@ wxConnectionBase *wxDDEClient::MakeConnection(const wxString& WXUNUSED(host),
         }
     }
 
-    return (wxConnectionBase*) NULL;
+    return NULL;
 }
 
 wxConnectionBase *wxDDEClient::OnMakeConnection()
@@ -451,7 +467,7 @@ wxConnectionBase *wxDDEClient::OnMakeConnection()
 
 wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 {
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     wxDDEConnection *found = NULL;
     while (node && !found)
     {
@@ -466,26 +482,25 @@ wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 // Only delete the entry in the map, not the actual connection
 bool wxDDEClient::DeleteConnection(WXHCONV conv)
 {
-    wxDDEConnectionList::Node *node = m_connections.GetFirst();
-    bool found = false;
-    while (node && !found)
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
+    while (node)
     {
         wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
         {
-            found = true;
-            delete node;
+            m_connections.Erase(node);
+            return true;
         }
         else node = node->GetNext();
     }
-    return found;
+    return false;
 }
 
 // ----------------------------------------------------------------------------
 // wxDDEConnection
 // ----------------------------------------------------------------------------
 
-wxDDEConnection::wxDDEConnection(wxChar *buffer, int size)
+wxDDEConnection::wxDDEConnection(void *buffer, size_t size)
      : wxConnectionBase(buffer, size)
 {
     m_client = NULL;
@@ -524,7 +539,7 @@ bool wxDDEConnection::Disconnect()
     bool ok = DdeDisconnect(GetHConv()) != 0;
     if ( !ok )
     {
-        DDELogError(_T("Failed to disconnect from DDE server gracefully"));
+        DDELogError(wxT("Failed to disconnect from DDE server gracefully"));
     }
 
     SetConnected( false );  // so we don't try and disconnect again
@@ -532,31 +547,115 @@ bool wxDDEConnection::Disconnect()
     return ok;
 }
 
-bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
+bool
+wxDDEConnection::DoExecute(const void *data, size_t size, wxIPCFormat format)
 {
-    DWORD result;
-    if (size < 0)
+    wxCHECK_MSG( format == wxIPC_TEXT ||
+                 format == wxIPC_UTF8TEXT ||
+                 format == wxIPC_UNICODETEXT,
+                 false,
+                 wxT("wxDDEServer::Execute() supports only text data") );
+
+    wxMemoryBuffer buffer;
+    LPBYTE realData = NULL;
+    size_t realSize = 0;
+    wxMBConv *conv = NULL;
+
+    // Windows only supports either ANSI or UTF-16 format depending on the
+    // build, so we need to convert the data if it doesn't use it already
+#if wxUSE_UNICODE
+    if ( format == wxIPC_TEXT )
+    {
+        conv = &wxConvLibc;
+    }
+    else if ( format == wxIPC_UTF8TEXT )
+    {
+        conv = &wxConvUTF8;
+    }
+    else // no conversion necessary for wxIPC_UNICODETEXT
+    {
+        realData = (LPBYTE)data;
+        realSize = size;
+    }
+
+    if ( conv )
+    {
+        const char * const text = (const char *)data;
+        const size_t len = size/sizeof(char);
+
+        realSize = conv->ToWChar(NULL, 0, text, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+
+        realData = (LPBYTE)buffer.GetWriteBuf(realSize*sizeof(wchar_t));
+        if ( !realData )
+            return false;
+
+        realSize = conv->ToWChar((wchar_t *)realData, realSize, text, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+    }
+#else // !wxUSE_UNICODE
+    if ( format == wxIPC_UNICODETEXT )
+    {
+        conv = &wxConvLibc;
+    }
+    else if ( format == wxIPC_UTF8TEXT )
+    {
+        // we could implement this in theory but it's not obvious how to pass
+        // the format information and, basically, why bother -- just use
+        // Unicode build
+        wxFAIL_MSG( wxT("UTF-8 text not supported in ANSI build") );
+
+        return false;
+    }
+    else // don't convert wxIPC_TEXT
     {
-        size = wxStrlen(data) + 1;
+        realData = (LPBYTE)data;
+        realSize = size;
     }
 
-    bool ok = DdeClientTransaction((LPBYTE)data, size,
-                                    GetHConv(),
-                                    NULL,
-                                    format,
-                                    XTYP_EXECUTE,
-                                    DDE_TIMEOUT,
-                                    &result) != 0;
+    if ( conv )
+    {
+        const wchar_t * const wtext = (const wchar_t *)data;
+        const size_t len = size/sizeof(wchar_t);
+
+        realSize = conv->FromWChar(NULL, 0, wtext, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+
+        realData = (LPBYTE)buffer.GetWriteBuf(realSize*sizeof(char));
+        if ( !realData )
+            return false;
+
+        realSize = conv->FromWChar((char*)realData, realSize, wtext, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+    }
+#endif // wxUSE_UNICODE/!wxUSE_UNICODE
+
+    DWORD result;
+    bool ok = DdeClientTransaction(realData,
+                                   realSize*sizeof(wxChar),
+                                   GetHConv(),
+                                   NULL,
+                                   // MSDN: if the transaction specified by
+                                   // the wType parameter does not pass data
+                                   // or is XTYP_EXECUTE, wFmt should be zero.
+                                   0,
+                                   XTYP_EXECUTE,
+                                   DDE_TIMEOUT,
+                                   &result) != 0;
 
     if ( !ok )
     {
-        DDELogError(_T("DDE execute request failed"));
+        DDELogError(wxT("DDE execute request failed"));
     }
 
     return ok;
 }
 
-wxChar *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat format)
+const void *wxDDEConnection::Request(const wxString& item, size_t *size, wxIPCFormat format)
 {
     DWORD result;
 
@@ -570,36 +669,33 @@ wxChar *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat fo
                                                   &result);
     if ( !returned_data )
     {
-        DDELogError(_T("DDE data request failed"));
+        DDELogError(wxT("DDE data request failed"));
 
         return NULL;
     }
 
     DWORD len = DdeGetData(returned_data, NULL, 0, 0);
 
-    wxChar *data = GetBufferAtLeast( len );
+    void *data = GetBufferAtLeast(len);
     wxASSERT_MSG(data != NULL,
-                 _T("Buffer too small in wxDDEConnection::Request") );
-    DdeGetData(returned_data, (LPBYTE)data, len, 0);
+                 wxT("Buffer too small in wxDDEConnection::Request") );
+    (void) DdeGetData(returned_data, (LPBYTE)data, len, 0);
 
-    DdeFreeDataHandle(returned_data);
+    (void) DdeFreeDataHandle(returned_data);
 
     if (size)
-        *size = (int)len;
+        *size = (size_t)len;
 
     return data;
 }
 
-bool wxDDEConnection::Poke(const wxString& item, wxChar *data, int size, wxIPCFormat format)
+bool wxDDEConnection::DoPoke(const wxString& item, const void *data, size_t size, wxIPCFormat format)
 {
     DWORD result;
-    if (size < 0)
-    {
-        size = wxStrlen(data) + 1;
-    }
 
     HSZ item_atom = DDEGetAtom(item);
-    bool ok = DdeClientTransaction((LPBYTE)data, size,
+    bool ok = DdeClientTransaction((LPBYTE)data,
+                                   size,
                                    GetHConv(),
                                    item_atom, format,
                                    XTYP_POKE,
@@ -652,21 +748,17 @@ bool wxDDEConnection::StopAdvise(const wxString& item)
 }
 
 // Calls that SERVER can make
-bool wxDDEConnection::Advise(const wxString& item,
-                             wxChar *data,
-                             int size,
-                             wxIPCFormat format)
+bool wxDDEConnection::DoAdvise(const wxString& item,
+                               const void *data,
+                               size_t size,
+                               wxIPCFormat format)
 {
-    if (size < 0)
-    {
-        size = wxStrlen(data) + 1;
-    }
-
     HSZ item_atom = DDEGetAtom(item);
     HSZ topic_atom = DDEGetAtom(m_topicName);
     m_sendingData = data;  // mrf: potential for scope problems here?
     m_dataSize = size;
-    m_dataType = format;
+    // wxIPC_PRIVATE does not succeed, so use text instead
+    m_dataType = format == wxIPC_PRIVATE ? wxIPC_TEXT : format;
 
     bool ok = DdePostAdvise(DDEIdInst, topic_atom, item_atom) != 0;
     if ( !ok )
@@ -677,12 +769,6 @@ bool wxDDEConnection::Advise(const wxString& item,
     return ok;
 }
 
-bool wxDDEConnection::OnDisconnect()
-{
-    delete this;
-    return true;
-}
-
 // ----------------------------------------------------------------------------
 // _DDECallback
 // ----------------------------------------------------------------------------
@@ -757,18 +843,27 @@ _DDECallback(WORD wType,
                 {
                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 
-                    wxChar *data = connection->GetBufferAtLeast( len );
+                    void *data = connection->GetBufferAtLeast(len);
                     wxASSERT_MSG(data != NULL,
-                                 _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
+                                 wxT("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
 
                     DdeGetData(hData, (LPBYTE)data, len, 0);
 
                     DdeFreeDataHandle(hData);
 
+                    // XTYP_EXECUTE can be used for text only and the text is
+                    // always in ANSI format for ANSI build and Unicode format
+                    // in Unicode build
+                    #if wxUSE_UNICODE
+                        wFmt = wxIPC_UNICODETEXT;
+                    #else
+                        wFmt = wxIPC_TEXT;
+                    #endif
+
                     if ( connection->OnExecute(connection->m_topicName,
                                                data,
                                                (int)len,
-                                               (wxIPCFormat) wFmt) )
+                                               (wxIPCFormat)wFmt) )
                     {
                         return (DDERETURN)(DWORD)DDE_FACK;
                     }
@@ -785,15 +880,26 @@ _DDECallback(WORD wType,
                 {
                     wxString item_name = DDEStringFromAtom(hsz2);
 
-                    int user_size = -1;
-                    wxChar *data = connection->OnRequest(connection->m_topicName,
-                                                       item_name,
-                                                       &user_size,
-                                                       (wxIPCFormat) wFmt);
+                    size_t user_size = wxNO_LEN;
+                    const void *data = connection->OnRequest(connection->m_topicName,
+                                                             item_name,
+                                                             &user_size,
+                                                             (wxIPCFormat)wFmt);
                     if (data)
                     {
-                        if (user_size < 0)
-                            user_size = wxStrlen((wxChar*)data) + 1;
+                      if (user_size == wxNO_LEN)
+                        switch (wFmt)
+                        {
+                          case wxIPC_TEXT:
+                          case wxIPC_UTF8TEXT:
+                            user_size = strlen((const char*)data) + 1;  // includes final NUL
+                            break;
+                          case wxIPC_UNICODETEXT:
+                            user_size = (wcslen((const wchar_t*)data) + 1) * sizeof(wchar_t);  // includes final NUL
+                            break;
+                          default:
+                            user_size = 0;
+                        }
 
                         HDDEDATA handle = DdeCreateDataHandle(DDEIdInst,
                                                               (LPBYTE)data,
@@ -818,9 +924,9 @@ _DDECallback(WORD wType,
 
                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 
-                    wxChar *data = connection->GetBufferAtLeast( len );
+                    void *data = connection->GetBufferAtLeast(len);
                     wxASSERT_MSG(data != NULL,
-                                 _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
+                                 wxT("Buffer too small in _DDECallback (XTYP_POKE)") );
 
                     DdeGetData(hData, (LPBYTE)data, len, 0);
 
@@ -905,9 +1011,9 @@ _DDECallback(WORD wType,
 
                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 
-                    wxChar *data = connection->GetBufferAtLeast( len );
+                    void *data = connection->GetBufferAtLeast(len);
                     wxASSERT_MSG(data != NULL,
-                                 _T("Buffer too small in _DDECallback (XTYP_ADVDATA)") );
+                                 wxT("Buffer too small in _DDECallback (XTYP_ADVDATA)") );
 
                     DdeGetData(hData, (LPBYTE)data, len, 0);
 
@@ -934,31 +1040,32 @@ _DDECallback(WORD wType,
 // ----------------------------------------------------------------------------
 
 // Atom table stuff
-static HSZ DDEAddAtom(const wxString& string)
+static HSZ DDEAddAtom(const wxString& str)
 {
-    HSZ atom = DDEAtomFromString(string);
-    wxAtomTable.Append(string, (wxObject *)atom);
+    HSZ atom = DDEAtomFromString(str);
+    wxAtomTable[str] = atom;
     return atom;
 }
 
-static HSZ DDEGetAtom(const wxString& string)
+static HSZ DDEGetAtom(const wxString& str)
 {
-    wxNode *node = wxAtomTable.Find(string);
-    if (node)
-        return (HSZ)node->GetData();
-    else
-    {
-        DDEAddAtom(string);
-        return (HSZ)(wxAtomTable.Find(string)->GetData());
-    }
+    wxAtomMap::iterator it = wxAtomTable.find(str);
+
+    if (it != wxAtomTable.end())
+        return it->second;
+
+    return DDEAddAtom(str);
 }
 
-// atom <-> strings
+/* atom <-> strings
+The returned handle has to be freed by the caller (using
+(static) DDEFreeString).
+*/
 static HSZ DDEAtomFromString(const wxString& s)
 {
-    wxASSERT_MSG( DDEIdInst, _T("DDE not initialized") );
+    wxASSERT_MSG( DDEIdInst, wxT("DDE not initialized") );
 
-    HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*) s.c_str(), DDE_CP);
+    HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*)s.wx_str(), DDE_CP);
     if ( !hsz )
     {
         DDELogError(_("Failed to create DDE string"));
@@ -973,12 +1080,20 @@ static wxString DDEStringFromAtom(HSZ hsz)
     static const size_t len = 256;
 
     wxString s;
-    (void)DdeQueryString(DDEIdInst, hsz, s.GetWriteBuf(len), len, DDE_CP);
-    s.UngetWriteBuf();
+    (void)DdeQueryString(DDEIdInst, hsz, wxStringBuffer(s, len), len, DDE_CP);
 
     return s;
 }
 
+static void DDEFreeString(HSZ hsz)
+{
+    // DS: Failure to free a string handle might indicate there's
+    // some other severe error.
+    bool ok = (::DdeFreeStringHandle(DDEIdInst, hsz) != 0);
+    wxASSERT_MSG( ok, wxT("Failed to free DDE string handle") );
+    wxUnusedVar(ok);
+}
+
 // ----------------------------------------------------------------------------
 // error handling
 // ----------------------------------------------------------------------------
@@ -990,7 +1105,7 @@ static void DDELogError(const wxString& s, UINT error)
         error = DdeGetLastError(DDEIdInst);
     }
 
-    wxLogError(s + _T(": ") + DDEGetErrorMsg(error));
+    wxLogError(s + wxT(": ") + DDEGetErrorMsg(error));
 }
 
 static wxString DDEGetErrorMsg(UINT error)