Program: 111974
Project: 111974
Buggy source:
@Test public void testWriteWithGroupWriter(){
  final String[] expected={"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str"};
  ColumnWriteStore columns=new ColumnWriteStore(){
    int counter=0;
    @Override public ColumnWriter getColumnWriter(    final ColumnDescriptor path){
      return new ColumnWriter(){
        private void validate(        Object value,        int repetitionLevel,        int definitionLevel){
          String actual=Arrays.toString(path.getPath()) + "String_Node_Str" + value+ "String_Node_Str"+ repetitionLevel+ "String_Node_Str"+ definitionLevel;
          assertEquals("String_Node_Str" + counter,expected[counter],actual);
          ++counter;
        }
        @Override public void writeNull(        int repetitionLevel,        int definitionLevel){
          validate(null,repetitionLevel,definitionLevel);
        }
        @Override public void write(        Binary value,        int repetitionLevel,        int definitionLevel){
          validate(value.toStringUsingUTF8(),repetitionLevel,definitionLevel);
        }
        @Override public void write(        boolean value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        int value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        long value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        float value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        double value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public Statistics getColumnStatistics(){
          throw new UnsupportedOperationException();
        }
        @Override public void flush(){
          throw new UnsupportedOperationException();
        }
        @Override public long getBufferedSizeInMemory(){
          throw new UnsupportedOperationException();
        }
      }
;
    }
    @Override public void flush(){
      assertEquals("String_Node_Str",expected.length,counter);
    }
  }
;
  MessageColumnIO columnIO=new ColumnIOFactory().getColumnIO(schema);
  GroupWriter groupWriter=new GroupWriter(columnIO.getRecordWriter(columns),schema);
  groupWriter.write(r1);
  groupWriter.write(r2);
  columns.flush();
}

Fixed version (ground truth):
@Test public void testWriteWithGroupWriter(){
  final String[] expected={"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str"};
  ColumnWriteStore columns=new ColumnWriteStore(){
    int counter=0;
    @Override public ColumnWriter getColumnWriter(    final ColumnDescriptor path){
      return new ColumnWriter(){
        private void validate(        Object value,        int repetitionLevel,        int definitionLevel){
          String actual=Arrays.toString(path.getPath()) + "String_Node_Str" + value+ "String_Node_Str"+ repetitionLevel+ "String_Node_Str"+ definitionLevel;
          assertEquals("String_Node_Str" + counter,expected[counter],actual);
          ++counter;
        }
        @Override public void writeNull(        int repetitionLevel,        int definitionLevel){
          validate(null,repetitionLevel,definitionLevel);
        }
        @Override public void write(        Binary value,        int repetitionLevel,        int definitionLevel){
          validate(value.toStringUsingUTF8(),repetitionLevel,definitionLevel);
        }
        @Override public void write(        boolean value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        int value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        long value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        float value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void write(        double value,        int repetitionLevel,        int definitionLevel){
          validate(value,repetitionLevel,definitionLevel);
        }
        @Override public void flush(){
          throw new UnsupportedOperationException();
        }
        @Override public long getBufferedSizeInMemory(){
          throw new UnsupportedOperationException();
        }
      }
;
    }
    @Override public void flush(){
      assertEquals("String_Node_Str",expected.length,counter);
    }
  }
;
  MessageColumnIO columnIO=new ColumnIOFactory().getColumnIO(schema);
  GroupWriter groupWriter=new GroupWriter(columnIO.getRecordWriter(columns),schema);
  groupWriter.write(r1);
  groupWriter.write(r2);
  columns.flush();
}