#i122752# check iterator in each iteration of CFormatEtcContainer::nextFormatEtc()'s loop

Don't trust nextFormatEtc()'s aNum argument not to mislead the iterator beyond
the container bounds. The comparable loop in CFormatEtcContainer::skipFormatEtc()
already checks the iterator against the container end in each iteration.

(cherry picked from commit a609daa1)

dtrans/source/win32/dtobj/FetcList.cxx

@@ -131,9 +131,10 @@ sal_uInt32 SAL_CALL CFormatEtcContainer::nextFormatEtc( LPFORMATETC lpFetc,
 
     sal_uInt32 nFetched = 0;
 
-    if ( m_EnumIterator != m_FormatMap.end( ) )
-    {
     for ( sal_uInt32 i = 0; i < aNum; i++, nFetched++, lpFetc++, ++m_EnumIterator )
+    {
+        if ( m_EnumIterator == m_FormatMap.end() )
+            break;
         CopyFormatEtc( lpFetc, *m_EnumIterator );
     }