Bug 177405 [Preferences] Layout issues with Text Boxes and Scrollbars
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
* 
			 * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)
			 */
			public void handleEvent(Event event) {
				if (event.detail == SWT.DRAG) {
					return;
				}
				int shift = event.x - sash.getBounds().x;
				GridData data = (GridData) rightControl.getLayoutData();
				int newWidthHint = data.widthHint + shift;
				if (newWidthHint < 20) {
					return;
				}
				Point computedSize = getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);
				Point currentSize = getShell().getSize();
				
				
				boolean customSize = !computedSize.equals(currentSize);
				data.widthHint = newWidthHint;
				setLastTreeWidth(newWidthHint);
				composite.layout(true);
				
				computedSize = getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);
				
				
				if (customSize) {
					computedSize.x = Math.max(computedSize.x, currentSize.x);
				}
				computedSize.y = Math.max(computedSize.y, currentSize.y);
				if (computedSize.equals(currentSize)) {