Fix crash when copying Unicode URLs to the clipboard.

Closes #11014.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@61506 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -121,6 +121,7 @@ All (GUI):
 
 wxMSW:
 
+- Fixed crash when copying Unicode URLs to the clipboard (Tim Kosse).
 - Fixed generation of wxEVT_CHAR_HOOK events.
 - Implement wxFileName::SetTimes() for directories (Steve Lamerton).
 - Correct wxTopLevelWindow::SetShape() for windows with menu bar (Peter Friis).

src/msw/ole/dataobj.cpp

@@ -1264,8 +1264,12 @@ void wxURLDataObject::SetURL(const wxString& url)
 
     // CFSTR_SHELLURL is always supposed to be ANSI...
     wxWX2MBbuf urlA = (wxWX2MBbuf)url.mbc_str();
-    size_t len = strlen(urlA);
-    SetData(wxDataFormat(CFSTR_SHELLURL), len+1, (const char*)urlA);
+    if ( url )
+    {
+        size_t len = strlen(urlA);
+        SetData(wxDataFormat(CFSTR_SHELLURL), len+1, (const char*)urlA);
+    }
+    //else: we can't represent this URL in the current code page
 }
 
 // ----------------------------------------------------------------------------