Doc & Symantec C++ fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1325 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/helpwin.cpp

@@ -96,7 +96,7 @@ bool wxWinHelpController::DisplaySection(int section)
 bool wxWinHelpController::DisplayBlock(long block)
 {
     // Use context number -- a very rough equivalent to block id!
-    if (!m_helpFile) return FALSE;
+    if (m_helpFile == "") return FALSE;
 
     char buf[_MAXPATHLEN];
     strcpy(buf, m_helpFile);