Selecting from a combo box while pressing CTRL results in an invalid selection

Using CTRL in JComboBox results in invalid selection.

In any JComboBox, if you press the CTRL key while selecting an item from the
list, the resulting selection will be a blank string.

To reproduce:
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1.
Install 1.3.1_17
2.
Open JDK demos in your browser
<JDK-HOME>/demo/jfc/SwingSet2/SwingSet2.html

3.
Select the ComboBox option

4.
click on the combo box to drop down. Press the CTRL key and then select the item using mouse.

5.
An empty string will be displayed as the choice.