Program: 6609
Project: 6609
Buggy source:
public boolean tryPowerSign(Block signBlock){
  if (!matchesMaterials(signBlock,signMaterials))   return false;
  Sign signState=(Sign)signBlock.getState();
  String command=signState.getLine(0);
  if (command.length() == 0 || command.charAt(0) != '!')   return false;
  failMsg="String_Node_Str";
  final String action;
  String[] result=matchPatterns(command,actionPattern);
  if (result == null) {
    debugFail("String_Node_Str");
    doDebugging(signBlock,2);
    return false;
  }
  action=result[0];
  try {
    boolean ret=false;
    if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],repeatPattern,verticalPattern,moveDirPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        return false;
      }
      final int repeat=(result[0] != null) ? Integer.parseInt(result[0]) : 1;
      if (repeat <= 0)       return false;
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[1]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace direction=getDirection(result[2],signDir,result[1]);
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryPushBlocks(startBlock,forward,moveTypes,repeat);
    }
 else     if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],repeatPattern,verticalPattern,moveDirPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        return false;
      }
      final int repeat=(result[0] != null) ? Integer.parseInt(result[0]) : 1;
      if (repeat <= 0)       return false;
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[1]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace direction=getDirection(result[2],signDir,result[1]);
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryPullBlocks(startBlock,forward,moveTypes,repeat);
    }
 else     if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],verticalPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        return false;
      }
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[0]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      signState.setLine(1,startBlock.getType().toString().toLowerCase());
      return true;
    }
 else     if (action.equals("String_Node_Str") || action.equals("String_Node_Str")) {
      BlockFace signDir=getSignDirection(signBlock);
      ret=tryLineAction(action,signState.getLine(1),signBlock,signDir);
    }
 else     if (action.equals("String_Node_Str")) {
      String[] oldResult=result;
      result=matchPatternsEnd(result[1],verticalPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        log.warning(Arrays.toString(oldResult));
        return false;
      }
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[0]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryActivate(startBlock,forward);
    }
 else     if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],verticalPattern);
      if (result == null) {
        failMsg="String_Node_Str";
        doDebugging(signBlock,2);
        return false;
      }
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[0]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryActivateLong(startBlock,forward);
    }
 else     if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],cannonTypePattern,verticalPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        return false;
      }
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[1]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryCannonSign(startBlock,forward,signState.getLine(1),result[0]);
    }
 else     if (action.equals("String_Node_Str")) {
      result=matchPatternsEnd(result[1],repeatPattern,verticalPattern,directionPattern);
      if (result == null) {
        debugFail("String_Node_Str");
        doDebugging(signBlock,2);
        return false;
      }
      final int repeat=(result[0] != null) ? Integer.parseInt(result[0]) : 1;
      if (repeat <= 0)       return false;
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,result[1]);
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace dir=strToDirection(result[2],forward);
      if (dir == null) {
        debugFail("String_Node_Str" + result[2]);
        doDebugging(signBlock,2);
        return false;
      }
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryInvPut(signBlock.getFace(dir),startBlock,forward,moveTypes,repeat);
    }
    debugFail("String_Node_Str");
    doDebugging(signBlock,ret ? 0 : 1);
    return ret;
  }
 catch (  Exception e) {
    e.printStackTrace();
    doDebugging(signBlock,10);
  }
  return false;
}

Fixed version (ground truth):
public boolean tryPowerSign(Block signBlock){
  if (!matchesMaterials(signBlock,signMaterials))   return false;
  Sign signState=(Sign)signBlock.getState();
  String command=signState.getLine(0);
  if (command.length() == 0 || command.charAt(0) != '!')   return false;
  failMsg="String_Node_Str";
  try {
    boolean ret=false;
    Matcher m=pushPattern.matcher(command);
    if (m.usePattern(pushPattern).matches()) {
      final int repeat=(m.group(1) != null) ? Integer.parseInt(m.group(1)) : 1;
      if (repeat <= 0)       return debugFail("String_Node_Str");
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace direction=getDirection(m.group(3),signDir,m.group(2));
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryPushBlocks(startBlock,forward,moveTypes,repeat);
    }
 else     if (m.usePattern(pullPattern).matches()) {
      final int repeat=(m.group(1) != null) ? Integer.parseInt(m.group(1)) : 1;
      if (repeat <= 0)       return debugFail("String_Node_Str");
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace direction=getDirection(m.group(3),signDir,m.group(2));
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryPullBlocks(startBlock,forward,moveTypes,repeat);
    }
 else     if (m.usePattern(detectPattern).matches()) {
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(1));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      signState.setLine(1,startBlock.getType().toString().toLowerCase());
      return true;
    }
 else     if (m.usePattern(linemovePattern).matches()) {
      BlockFace signDir=getSignDirection(signBlock);
      ret=tryLineAction(m.group(1),signState.getLine(1),signBlock,signDir);
    }
 else     if (m.usePattern(activatePattern).matches()) {
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryActivate(startBlock,forward,m.group(1).equals("String_Node_Str"));
    }
 else     if (m.usePattern(activateLongPattern).matches()) {
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(1));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryActivateLong(startBlock,forward);
    }
 else     if (m.usePattern(cannonPattern).matches()) {
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      ret=tryCannonSign(startBlock,forward,signState.getLine(1),m.group(1));
    }
 else     if (m.usePattern(invpushPattern).matches()) {
      final int repeat=(m.group(1) != null) ? Integer.parseInt(m.group(1)) : 1;
      if (repeat <= 0)       return debugFail("String_Node_Str");
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace dir=strToDirection(m.group(3),signDir);
      if (dir == null) {
        debugFail("String_Node_Str" + m.group(3));
        doDebugging(signBlock,2);
        return false;
      }
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryInvPush(signBlock.getFace(dir),startBlock,forward,moveTypes,repeat);
    }
 else     if (m.usePattern(invpullPattern).matches()) {
      final int repeat=(m.group(1) != null) ? Integer.parseInt(m.group(1)) : 1;
      if (repeat <= 0)       return debugFail("String_Node_Str");
      BlockFace signDir=getSignDirection(signBlock);
      BlockFace forward=getForward(signDir,m.group(2));
      Block startBlock=getStartBlock(signBlock,signDir,forward).getFace(forward,1);
      BlockFace dir=strToDirection(m.group(3),signDir);
      if (dir == null) {
        debugFail("String_Node_Str" + m.group(3));
        doDebugging(signBlock,2);
        return false;
      }
      Material[] moveTypes=getMaterials(signState.getLine(1));
      ret=tryInvPull(signBlock.getFace(dir),startBlock,forward,moveTypes,repeat);
    }
 else {
      debugFail("String_Node_Str");
      doDebugging(signBlock,2);
      return false;
    }
    debugFail("String_Node_Str");
    doDebugging(signBlock,ret ? 0 : 1);
    return ret;
  }
 catch (  Exception e) {
    e.printStackTrace();
    doDebugging(signBlock,10);
  }
  return false;
}