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
String desc = psEntry.getDescription();
    			if (desc != null && desc.length() > 0) {
					setMessage(psEntry.getDescription());
				} else {
					setMessage(psEntry.getDisplayName());
				}
    		}
    			
    		else if (item.getData() instanceof PropertySheetCategory) {
    			PropertySheetCategory psCat = (PropertySheetCategory) item.getData();
    			setMessage(psCat.getCategoryName());
    		}
    	}
	}
    /**
     * Updates all of the items in the tree.
     * <p>
     * Note that this means ensuring that the tree items reflect the state of
     * the model (entry tree) it does not mean telling the model to update
     * itself.
     * </p>
     */
    public void refresh() {
        if (rootEntry != null) {
            updateChildrenOf(rootEntry, tree);
        }
    }
    /**
     * Removes the given cell editor activation listener from this viewer. Has
     * no effect if an identical activation listener is not registered.