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
for (int i = 0; i < listeners.length; ++i) {
            ((ICellEditorActivationListener) listeners[i])
                    .cellEditorDeactivated(activatedCellEditor);
        }
    }
    /**
     * Returns the active cell editor of this property sheet viewer or
     * <code>null</code> if no cell editor is active.
     * 
     * @return the active cell editor
     */
    public CellEditor getActiveCellEditor() {
        return cellEditor;
    }
    private TreeItem[] getChildItems(Widget widget) {
        if (widget instanceof Tree) {
            return ((Tree) widget).getItems();
        }
        else if (widget instanceof TreeItem) {
            return ((TreeItem) widget).getItems();
        }
        
        return new TreeItem[0];
    }
    
    /**
     * Returns the sorted children of the given category or entry
     *
     * @param node a category or entry
     * @return the children of the given category or entry