Program: 21108
Project: 21108
Buggy source:
private boolean checkUnrarCommandIntern(){
  String path=this.getPluginConfig().getStringProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
  String hash=this.getPluginConfig().getStringProperty(JDUnrarConstants.UNRAR_HASH,null);
  if (hash != null && hash.length() == 32 && path != null && path.length() != 0) {
    String curhash=JDHash.getMD5(path);
    if (curhash != null && curhash.equalsIgnoreCase(hash))     return true;
  }
 else {
    path=null;
    hash=null;
  }
  if (path == null || path.length() == 0) {
    if (OSDetector.isWindows()) {
      path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
      this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
      this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
      this.getPluginConfig().save();
      return true;
    }
 else {
      if (OSDetector.isLinux()) {
        path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
        chmodUnrar(path);
        if (isUnrarCommandValid(path)) {
          this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
          this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
          this.getPluginConfig().save();
          return true;
        }
      }
      if (OSDetector.isMac()) {
        path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
        chmodUnrar(path);
        if (isUnrarCommandValid(path)) {
          this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
          this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
          this.getPluginConfig().save();
          return true;
        }
      }
      if (isUnrarCommandValid("String_Node_Str")) {
        path="String_Node_Str";
        this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
        this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
        this.getPluginConfig().save();
        return true;
      }
      if (isUnrarCommandValid("String_Node_Str")) {
        path="String_Node_Str";
        this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
        this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
        this.getPluginConfig().save();
        return true;
      }
      try {
        String[] charset=System.getenv("String_Node_Str").split("String_Node_Str");
        for (        String element : charset) {
          File fi=new File(element,"String_Node_Str");
          File fi2=new File(element,"String_Node_Str");
          if (fi.isFile() && isUnrarCommandValid(fi.getAbsolutePath())) {
            path=fi.getAbsolutePath();
            this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
            this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
            this.getPluginConfig().save();
            return true;
          }
 else           if (fi2.isFile() && isUnrarCommandValid(fi2.getAbsolutePath())) {
            path=fi2.getAbsolutePath();
            this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
            this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
            this.getPluginConfig().save();
            return true;
          }
        }
      }
 catch (      Throwable e) {
      }
      this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
      this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,null);
      this.getPluginConfig().save();
      return false;
    }
  }
  this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
  this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,null);
  this.getPluginConfig().save();
  return false;
}

Fixed version (ground truth):
private boolean checkUnrarCommandIntern(){
  String path=this.getPluginConfig().getStringProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
  String hash=this.getPluginConfig().getStringProperty(JDUnrarConstants.UNRAR_HASH,null);
  if (hash != null && hash.length() == 32 && path != null && path.length() != 0) {
    String curhash=JDHash.getMD5(new File(path));
    if (curhash != null && curhash.equalsIgnoreCase(hash))     return true;
  }
 else {
    path=null;
    hash=null;
  }
  if (path == null || path.length() == 0) {
    if (OSDetector.isWindows()) {
      path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
      this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
      this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
      this.getPluginConfig().save();
      return true;
    }
 else {
      if (OSDetector.isLinux()) {
        path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
        chmodUnrar(path);
        if (isUnrarCommandValid(path)) {
          this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
          this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
          this.getPluginConfig().save();
          return true;
        }
      }
      if (OSDetector.isMac()) {
        path=JDUtilities.getResourceFile("String_Node_Str").getAbsolutePath();
        chmodUnrar(path);
        if (isUnrarCommandValid(path)) {
          this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
          this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
          this.getPluginConfig().save();
          return true;
        }
      }
      if (isUnrarCommandValid("String_Node_Str")) {
        path="String_Node_Str";
        this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
        this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
        this.getPluginConfig().save();
        return true;
      }
      if (isUnrarCommandValid("String_Node_Str")) {
        path="String_Node_Str";
        this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
        this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
        this.getPluginConfig().save();
        return true;
      }
      try {
        String[] charset=System.getenv("String_Node_Str").split("String_Node_Str");
        for (        String element : charset) {
          File fi=new File(element,"String_Node_Str");
          File fi2=new File(element,"String_Node_Str");
          if (fi.isFile() && isUnrarCommandValid(fi.getAbsolutePath())) {
            path=fi.getAbsolutePath();
            this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
            this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
            this.getPluginConfig().save();
            return true;
          }
 else           if (fi2.isFile() && isUnrarCommandValid(fi2.getAbsolutePath())) {
            path=fi2.getAbsolutePath();
            this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,path);
            this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,JDHash.getMD5(path));
            this.getPluginConfig().save();
            return true;
          }
        }
      }
 catch (      Throwable e) {
      }
      this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
      this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,null);
      this.getPluginConfig().save();
      return false;
    }
  }
  this.getPluginConfig().setProperty(JDUnrarConstants.CONFIG_KEY_UNRARCOMMAND,null);
  this.getPluginConfig().setProperty(JDUnrarConstants.UNRAR_HASH,null);
  this.getPluginConfig().save();
  return false;
}