Bug 56818 [PropertiesView] Clicking on Advanced Properties toggle when categories are collapsed removes the + next to the category
Clicking on Advanced Properties toggle when categories are collapsed removes the plus sign (+) next to the category and it can no longer be expanded. To reproduce: 1.)Open the Properties view. 2.)Have Show Categories turned on, and Show Advanced Properties turned off. 3.)Collapse all open categories. 4.)Click the Show Advanced Properties button. 5.)Note the plus sign goes away and the categories can no longer be expanded. You need to click the Show Advanced Properties button off to see the plus sign again.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetViewer.java
activateCellEditor(sel[0]);
			}
		}
		entrySelectionChanged();
	}
	/**
	 * The expand icon for a node in this viewer has been selected to collapse a
	 * subtree. Deactivate the cell editor
	 * 
	 * @param event
	 *            the SWT tree event
	 */
	private void handleTreeCollapse(TreeEvent event) {
		if (cellEditor != null) {
			applyEditorValue();
			deactivateCellEditor();
		}
	}
	/**
	 * The expand icon for a node in this viewer has been selected to expand the
	 * subtree. Create the children 1 level deep.
	 * <p>
	 * Note that we use a "dummy" item (no user data) to show a "+" icon beside
	 * an item which has children before the item is expanded now that it is
	 * being expanded we have to create the real child items
	 * </p>
	 * 
	 * @param event
	 *            the SWT tree event