null pointer guard if no user defined types declared at the module level

Change-Id: I368a168c636e4029e9cd9bbe4a4df5d9b846c923
Reviewed-on: https://gerrit.libreoffice.org/17834Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

basic/source/classes/image.cxx

@@ -443,6 +443,8 @@ bool SbiImage::Save( SvStream& r, sal_uInt32 nVer )
         SbiCloseRecord( r, nPos );
     }
     // User defined types
+    if (rTypes)
+    {
         sal_uInt16 nTypes = rTypes->Count();
         if (nTypes > 0 )
         {
@@ -517,6 +519,7 @@ bool SbiImage::Save( SvStream& r, sal_uInt32 nVer )
             }
         SbiCloseRecord( r, nPos );
         }
+    }
     // Set overall length
     SbiCloseRecord( r, nStart );
     if( !SbiGood( r ) )