#4 xmlformat and sb (StringBuffer)

[ivanxma]

The section inside

public synchronized void addSolution( int solverIndex )

throws nullpointer exception if xmlformat is
specified. The sb doesn't get created.

StringBuilder sb = ! xmlFormat ? new
StringBuilder() : null ;
if( logical ){
category = EASY ;
if( lockedSectorCandidates ){
category = MEDIUM ; ...