- *DataPtr = (Uint8*)Buffer->SubBuffers[Index].Data + Buffer->SubBuffers[Index].PreLength;
- *Length = Buffer->SubBuffers[Index].PostLength;
+ if( DataPtr )
+ *DataPtr = (Uint8*)Buffer->SubBuffers[Index].Data + Buffer->SubBuffers[Index].PreLength;
+ if( Length )
+ *Length = Buffer->SubBuffers[Index].PostLength;