1. Added m_count and maintain its value in InsertItem, RemoveItem

etc. and return it from GetItemCount to save so many calls to
   ListView_GetItemCount.

2. If EVT_LIST_DELETE_ALL_ITEMS was not handled then the
   post-processing code to prevent LVN_DELETEITEM messages was not
   getting executed.  Changed it so the post processing always
   happens.

3. It's possible with some versions of comctl32 that garbage values
   can be passed in nmLV->lParam so don't try to get the internal item
   data pointer from it.  This should close bug# 659939

4. Added FreeAllInternalData from DeleteAllItems, (part of patch
   #672065) and also guard against processing LVN_CHANG* messages
   while freeing the internal data.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@19021 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/listctrl.h

@@ -370,6 +370,9 @@ protected:
     long              m_baseStyle;  // Basic Windows style flags, for recreation purposes
     int               m_colCount;   // Windows doesn't have GetColumnCount so must
                                     // keep track of inserted/deleted columns
+    long              m_count;      // Keep track of item count to save calls to
+                                    // ListView_GetItemCount
+    bool              m_ignoreChangeMessages;
 
     // TRUE if we have any internal data (user data & attributes)
     bool m_AnyInternalData;

src/msw/listctrl.cpp

@@ -244,6 +244,8 @@ void wxListCtrl::Init()
     m_ownsImageListNormal = m_ownsImageListSmall = m_ownsImageListState = FALSE;
     m_baseStyle = 0;
     m_colCount = 0;
+    m_count = 0;
+    m_ignoreChangeMessages = FALSE;
     m_textCtrl = NULL;
     m_AnyInternalData = FALSE;
     m_hasAnyAttr = FALSE;
@@ -378,8 +380,10 @@ void wxListCtrl::FreeAllInternalData()
         int n = GetItemCount();
         int i = 0;
 
+        m_ignoreChangeMessages = TRUE;
         for (i = 0; i < n; i++)
             wxDeleteInternalData(this, i);
+        m_ignoreChangeMessages = TRUE;
 
         m_AnyInternalData = FALSE;
     }
@@ -1014,7 +1018,7 @@ bool wxListCtrl::SetItemPosition(long item, const wxPoint& pos)
 // Gets the number of items in the list control
 int wxListCtrl::GetItemCount() const
 {
-    return ListView_GetItemCount(GetHwnd());
+    return m_count;
 }
 
 // Retrieves the spacing between icons in pixels.
@@ -1204,6 +1208,10 @@ bool wxListCtrl::DeleteItem(long item)
         return FALSE;
     }
 
+    m_count -= 1;
+    wxASSERT_MSG( m_count == ListView_GetItemCount(GetHwnd()),
+                  wxT("m_count should match ListView_GetItemCount"));
+
     // the virtual list control doesn't refresh itself correctly, help it
     if ( IsVirtual() )
     {
@@ -1232,6 +1240,7 @@ bool wxListCtrl::DeleteItem(long item)
 // Deletes all items
 bool wxListCtrl::DeleteAllItems()
 {
+    FreeAllInternalData();
     return ListView_DeleteAllItems(GetHwnd()) != 0;
 }
 
@@ -1448,8 +1457,12 @@ long wxListCtrl::InsertItem(wxListItem& info)
     }
     };
 
+    long rv = ListView_InsertItem(GetHwnd(), & item);
+    m_count += 1;
+    wxASSERT_MSG( m_count == ListView_GetItemCount(GetHwnd()),
+                  wxT("m_count should match ListView_GetItemCount"));
 
-    return (long) ListView_InsertItem(GetHwnd(), & item);
+    return rv;
 }
 
 long wxListCtrl::InsertItem(long index, const wxString& label)
@@ -1641,6 +1654,7 @@ bool wxListCtrl::MSWCommand(WXUINT cmd, WXWORD id)
 
 bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
 {
+
     // prepare the event
     // -----------------
 
@@ -1770,53 +1784,29 @@ bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
 
         const int iItem = nmLV->iItem;
 
-        // set the data event field for all messages for which the system gives
+
-        // us a valid NM_LISTVIEW::lParam
+        // FreeAllInternalData will cause LVN_ITEMCHANG* messages, which can be
-        switch ( nmLV->hdr.code )
+        // ignored for efficiency.  It is done here because the internal data is in the
+        // process of being deleted so we don't want to try and access it below.
+        if ( m_ignoreChangeMessages &&
+             ( (nmLV->hdr.code == LVN_ITEMCHANGED) || (nmLV->hdr.code == LVN_ITEMCHANGING)))
         {
-            case LVN_BEGINDRAG:
+            return TRUE;
-            case LVN_BEGINRDRAG:
-            case LVN_COLUMNCLICK:
-            case LVN_ITEMCHANGED:
-            case LVN_ITEMCHANGING:
-                if ( iItem != -1 )
-                {
-                    if ( iItem >= GetItemCount() )
-                    {
-                        // there is apparently a bug in comctl32.dll version
-                        // 5.50.4704.1100 (note that the MS DLL database
-                        // doesn't say what this version is, it's not the one
-                        // shipped with W2K although the bug was reported under
-                        // that system) and it sends us LVN_ITEMCHANGING
-                        // notifications with the item out of range -- and as
-                        // we access the items client data, we crash below
-                        //
-                        // see
-                        //
-                        //  http://lists.wxwindows.org/cgi-bin/ezmlm-cgi?8:mss:29852:knlihdmadhaljafjajei
-                        //
-                        // and the thread continuation for more details
-                        // (although note that the bug may be present in other
-                        // versions of comctl32.dll as well as it has been
-                        // reported quite a few times)
-                        //
-                        // to fix this, simply ignore these "bad" events (as
-                        // above with HDN_GETDISPINFOW)
-                        return TRUE;
-                    }
-
-                    wxListItemInternalData *internaldata =
-                        (wxListItemInternalData *) nmLV->lParam;
-
-                    if ( internaldata )
-                        event.m_item.m_data = internaldata->lParam;
-                }
-
-            default:
-                // fall through
-                ;
         }
 
+
+        // If we have a valid item then check if there is a data value
+        // associated with it and put it in the event.
+        if ( iItem >= 0 && iItem < GetItemCount() )
+        {
+            wxListItemInternalData *internaldata =
+                wxGetInternalData(GetHwnd(), iItem);
+
+            if ( internaldata )
+                event.m_item.m_data = internaldata->lParam;
+        }
+
+
         switch ( nmhdr->code )
         {
             case LVN_BEGINRDRAG:
@@ -1885,11 +1875,17 @@ bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
                 break;
 
             case LVN_DELETEALLITEMS:
+                m_count = 0;
                 eventType = wxEVT_COMMAND_LIST_DELETE_ALL_ITEMS;
                 event.m_itemIndex = -1;
                 break;
 
             case LVN_DELETEITEM:
+                if (m_count == 0)
+                    // this should be prevented by the post-processing code below,
+                    // but "just in case"
+                    return FALSE;
+
                 eventType = wxEVT_COMMAND_LIST_DELETE_ITEM;
                 event.m_itemIndex = iItem;
                 // delete the assoicated internal data
@@ -2133,12 +2129,10 @@ bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
 
     event.SetEventType(eventType);
 
-    if ( !GetEventHandler()->ProcessEvent(event) )
+    bool processed = GetEventHandler()->ProcessEvent(event);
-        return FALSE;
 
     // post processing
     // ---------------
-
     switch ( nmhdr->code )
     {
         case LVN_DELETEALLITEMS:
@@ -2146,7 +2140,6 @@ bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
             // notifications - this makes deleting all items from a list ctrl
             // much faster
             *result = TRUE;
-
             return TRUE;
 
         case LVN_ENDLABELEDITA:
@@ -2168,9 +2161,10 @@ bool wxListCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
             return TRUE;
     }
 
-    *result = !event.IsAllowed();
+    if ( processed )
+        *result = !event.IsAllowed();
 
-    return TRUE;
+    return processed;
 }
 
 #if defined(_WIN32_IE) && _WIN32_IE >= 0x300
@@ -2370,6 +2364,9 @@ void wxListCtrl::SetItemCount(long count)
     {
         wxLogLastError(_T("ListView_SetItemCount"));
     }
+    m_count = count;
+    wxASSERT_MSG( m_count == ListView_GetItemCount(GetHwnd()),
+                  wxT("m_count should match ListView_GetItemCount"));
 }
 
 void wxListCtrl::RefreshItem(long item)