Bug 276202 [Forms] NPE if dispose() called on FormToolkit more than once
Build id: I20090512-2000 java.lang.NullPointerException at org.eclipse.ui.forms.widgets.FormToolkit.dispose(FormToolkit.java:711) At the moment, if you invoke dispose() twice on a FormToolkit instance, an NPE will be thrown. public void dispose() { if (colors.isShared() == false) { colors.dispose(); colors = null; } boldFontHolder.dispose(); } As can be seen, the 'colors' field is set to 'null' which is the cause of the NPE. It's okay to repeatedly invoke dispose() on an SWT widget so I feel this pattern should be extended for a FormToolkit also.
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/forms/widgets/FormToolkit.java
gc.fillGradientRectangle(0, 0, bounds.width, bounds.height,
						false);
			}
		});
		if (parent instanceof Section)
			((Section) parent).setSeparatorControl(composite);
		return composite;
	}
	/**
	 * Creates a label as a part of the form.
	 * 
	 * @param parent
	 *            the label parent
	 * @param text
	 *            the label text
	 * @return the label widget
	 */
	public Label createLabel(Composite parent, String text) {
		return createLabel(parent, text, SWT.NONE);
	}
	/**
	 * Creates a label as a part of the form.
	 * 
	 * @param parent
	 *            the label parent
	 * @param text
	 *            the label text
	 * @param style
	 *            the label style
	 * @return the label widget