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
Control control = cellEditor.getControl();
        if (control == null) {
            cellEditor.deactivate();
            cellEditor = null;
            return;
        }
        
        cellEditor.addListener(editorListener);
        
        CellEditor.LayoutData layout = cellEditor.getLayoutData();
        treeEditor.horizontalAlignment = layout.horizontalAlignment;
        treeEditor.grabHorizontal = layout.grabHorizontal;
        treeEditor.minimumWidth = layout.minimumWidth;
        treeEditor.setEditor(control, item, columnToEdit);
        
        setErrorMessage(cellEditor.getErrorMessage());
        
        cellEditor.setFocus();
        
        fireCellEditorActivated(cellEditor);
    }
    /**
     * Adds a cell editor activation listener. Has no effect if an identical
     * activation listener is already registered.
     * 
     * @param listener
     *            a cell editor activation listener
     */