Bug 258016 [PropertiesView] NPE in org.eclipse.ui.views.properties.PropertySheetViewer
At line 720. If the selection is null this will result in an NPE. Here is the offending code snippet: 714: // get the new selection 715: TreeItem[] sel = new TreeItem[] { selection }; 716: if (sel.length == 0) { 717: setMessage(null); 718: setErrorMessage(null); 719: } else { 720: Object object = sel[0].getData(); // assume single selection It would be better replaced with the following (sorry, no patch, I'm not set up for editing the platform!): // get the new selection TreeItem sel = new TreeItem[] { selection; if (selection == null) { setMessage(null); setErrorMessage(null); } else { Object object = selection.getData(); // assume single selection if (object instanceof IPropertySheetEntry) { // get the entry for this item IPropertySheetEntry activeEntry = (IPropertySheetEntry) object; // display the description for the item setMessage(activeEntry.getDescription()); // activate a cell editor on the selection activateCellEditor(selection); } } In fact, I'm not at all sure why the selection was being wrapped in a single element array at all, I'm guessing a holdover from old code?
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetViewer.java
TreeItem findItem = findItem(entry, childItem);
            if (findItem != null) {
				return findItem;
			}
        }
        return null;
    }
    /**
     * Notifies all registered cell editor activation listeners of a cell editor
     * activation.
     * 
     * @param activatedCellEditor
     *            the activated cell editor
     */
    private void fireCellEditorActivated(CellEditor activatedCellEditor) {
        Object[] listeners = activationListeners.getListeners();
        for (int i = 0; i < listeners.length; ++i) {
            ((ICellEditorActivationListener) listeners[i])
                    .cellEditorActivated(activatedCellEditor);
        }
    }
    /**
     * Notifies all registered cell editor activation listeners of a cell editor
     * deactivation.
     * 
     * @param activatedCellEditor
     *            the deactivated cell editor
     */
    private void fireCellEditorDeactivated(CellEditor activatedCellEditor) {
        Object[] listeners = activationListeners.getListeners();