Program: 151797
Project: 151797
Buggy source:
public void check(boolean beforeBackup){
  try {
    long neededSizeKb=0;
    if (beforeBackup) {
      neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(new File(server.options.get("String_Node_Str"))) / 1024) * 2;
      File world_nether=new File(server.options.get("String_Node_Str") + "String_Node_Str");
      if (world_nether.exists()) {
        neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(world_nether) / 1024) * 2;
      }
      File plugins=new File("String_Node_Str");
      if (plugins.exists()) {
        neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(plugins) / 1024) * 2;
      }
    }
 else {
      neededSizeKb=50 * 1024;
    }
    long freeSpaceKb=FileSystemUtils.freeSpaceKb();
    if (freeSpaceKb < neededSizeKb) {
      System.out.println("String_Node_Str" + Math.round(freeSpaceKb / 1024) + "String_Node_Str");
      System.out.println("String_Node_Str");
      int filesDeleted=0;
      while (FileSystemUtils.freeSpaceKb() < neededSizeKb) {
        File firstCreatedFile=AutoBackup.oldestBackup();
        if (firstCreatedFile != null) {
          System.out.println("String_Node_Str" + firstCreatedFile.getPath());
          firstCreatedFile.delete();
          filesDeleted++;
        }
 else {
          System.out.println("String_Node_Str");
          return;
        }
      }
      if (filesDeleted > 1) {
        System.out.println("String_Node_Str" + filesDeleted + "String_Node_Str");
      }
 else {
        System.out.println("String_Node_Str");
      }
    }
  }
 catch (  IOException e) {
    System.out.println("String_Node_Str" + e);
    System.out.println("String_Node_Str");
  }
}

Fixed version (ground truth):
public void check(boolean beforeBackup){
  try {
    long neededSizeKb=0;
    if (beforeBackup) {
      neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(new File(server.options.get("String_Node_Str"))) / 1024) * 2;
      File world_nether=new File(server.options.get("String_Node_Str") + "String_Node_Str");
      if (world_nether.exists()) {
        neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(world_nether) / 1024) * 2;
      }
      File plugins=new File("String_Node_Str");
      if (plugins.exists()) {
        neededSizeKb+=Math.round(FileUtils.sizeOfDirectory(plugins) / 1024) * 2;
      }
    }
 else {
      neededSizeKb=50 * 1024;
    }
    long freeSpaceKb=FileSystemUtils.freeSpaceKb();
    if (freeSpaceKb < neededSizeKb) {
      System.out.println("String_Node_Str" + Math.round(freeSpaceKb / 1024) + "String_Node_Str");
      System.out.println("String_Node_Str");
      int filesDeleted=0;
      while (FileSystemUtils.freeSpaceKb() < neededSizeKb) {
        File firstCreatedFile=AutoBackup.oldestBackup();
        if (firstCreatedFile != null) {
          System.out.println("String_Node_Str" + firstCreatedFile.getPath());
          firstCreatedFile.delete();
          filesDeleted++;
        }
 else {
          System.out.println("String_Node_Str");
          return;
        }
      }
      if (filesDeleted > 1) {
        System.out.println("String_Node_Str" + filesDeleted + "String_Node_Str");
      }
 else {
        System.out.println("String_Node_Str");
      }
    }
  }
 catch (  IOException e) {
    System.out.println("String_Node_Str" + e);
    System.out.println("String_Node_Str");
  }
catch (  IllegalArgumentException e) {
    System.out.println("String_Node_Str" + e);
    System.out.println("String_Node_Str");
  }
}