Bug 95548 Editors page not sized properly on startup
build N20050517, open preferences dialog to editors page (under General). now close and open the dialog again and note that the dialog is too short.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
} finally {
					viewer.addPostSelectionChangedListener(this);
				}
			}
			public void selectionChanged(SelectionChangedEvent event) {
				Object selection = getSingleSelection(event.getSelection());
				if (selection instanceof IPreferenceNode) {
					if (!isCurrentPageValid()) {
						handleError();
					} else if (!showPage((IPreferenceNode) selection)) {
						
						handleError();
					} else {
						
						lastSuccessfulNode = (IPreferenceNode) selection;
					}
				}
			}
		});
		((Tree) viewer.getControl()).addSelectionListener(new SelectionAdapter() {
			public void widgetDefaultSelected(final SelectionEvent event) {
				ISelection selection = viewer.getSelection();
				if (selection.isEmpty())
					return;
				IPreferenceNode singleSelection = getSingleSelection(selection);
				boolean expanded = viewer.getExpandedState(singleSelection);
				viewer.setExpandedState(singleSelection, !expanded);
			}
		});