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
* not visible in the viewer.
     * 
     * @return the root entry or <code>null</code>.
     */
    public IPropertySheetEntry getRootEntry() {
        return rootEntry;
    }
    /**
     * The <code>PropertySheetViewer</code> implementation of this
     * <code>ISelectionProvider</code> method returns the result as a
     * <code>StructuredSelection</code>.
     * <p>
     * Note that this method only includes <code>IPropertySheetEntry</code> in
     * the selection (no categories).
     * </p>
     */
    public ISelection getSelection() {
        if (tree.getSelectionCount() == 0) {
			return StructuredSelection.EMPTY;
		}
        TreeItem[] sel = tree.getSelection();
        List entries = new ArrayList(sel.length);
        for (int i = 0; i < sel.length; i++) {
            TreeItem ti = sel[i];
            Object data = ti.getData();
            if (data instanceof IPropertySheetEntry) {
				entries.add(data);
			}
        }
        return new StructuredSelection(entries);