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
PropertySheetCategory[] categoryArray = (PropertySheetCategory[]) categoryList
        	.toArray(new PropertySheetCategory[categoryList.size()]);
        sorter.sort(categoryArray);
        categories = categoryArray;
    }
    /**
     * Update the category (but not its parent or children).
     * 
     * @param category
     *            the category to update
     * @param item
     *            the tree item for the given entry
     */
    private void updateCategory(PropertySheetCategory category,
            TreeItem item) {
        
        item.setData(category);
        
        
        entryToItemMap.put(category, item);
        
        item.setText(0, category.getCategoryName());
        item.setText(1, ""); 
        
        if (category.getAutoExpand()) {
            
            createChildren(item);
            item.setExpanded(true);
            category.setAutoExpand(false);