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 item = null;
        if (widget instanceof TreeItem) {
            item = (TreeItem) widget;
        }
        if (item != null && !item.getExpanded()) {
            
            for (int i = 0; i < childItems.length; i++) {
                if (childItems[i].getData() != null) {
                    removeItem(childItems[i]);
                }
            }
            
            if (category != null || entry.hasChildEntries()) {
                
                
                
                
                
                
                
                childItems = getChildItems(widget);
                if (childItems.length == 0) {
                    new TreeItem(item, SWT.NULL);
                }
            }
            return;
        }
        
        if (node == rootEntry && isShowingCategories) {