A DESCRIPTION OF THE PROBLEM :
When trying to repaint a rectangle spanning more than a single row, parts of the affected rectangle just become blank instead of painting the actual content.
The bug seems to be introduced due to changes made to BasicTableUI by "8081491: The case print incomplete." and "8159068: The rendering of JTable is broken". The issue is partly fixed in Java 12 by "8202702: Clearing selection on JTable causes disappearance of a row" but only when the repainted rectangle does not intersect more than a single row.
The issue does not occur if a row is selected or the parent component of the table is a JScrollPane or a JViewPort.

REGRESSION : Last worked in version 8u231

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Simply call JTable.repaint(Rectangle) with a rectangle spanning more than one row

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The containing area of the rectangle is repainted completely
ACTUAL -
Parts of the rectangle are not repainted and are left blank, showing only the background color.

---------- BEGIN SOURCE ----------
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    TableModel model = new DefaultTableModel(
        new String[][] { { "A0", "B0" }, { "A1", "B1" }, { "A2", "B2" }, { "A3", "B3" } },
        new String[] { "A", "B" });
    JTable table = new JTable(model);
    frame.add(table);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();
    frame.setSize(200, 200);
    frame.setVisible(true);
    SwingUtilities.invokeLater(() -> repaintRows(table));
  }

  private static void repaintRows(JTable table) {
    // get Rectangle for second row
    Rectangle r = table.getCellRect(1, 0, true);
    // expand cell rectangle to affect (parts of) third row
    r = new Rectangle(0, r.y, table.getWidth(), r.height * 2);
    table.repaint(r);
  }
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Embedding the JTable into a JScrollPane or JViewPort. Alternatively simply repainting the whole table seems to work.

FREQUENCY : always