Bug 67814 Show In > Package Explorer doesn't ask for removal of last filter [package explorer]
200406180010; Not a dup of 66646. 'Show In > Package Explorer' doesn't ask for removal of a filter iff there's only a single filter set. Steps: - Disable all filters in Package Explorer, except for 'Referenced Libraries'. - Open editor for java.util.Vector - Navigate > Show In > Package Explorer => fails, doesn't ask for filter removal. Works iff at least one other filter (which would not filter the element) is active.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/CustomFiltersActionGroup.java
store.setValue(getPreferenceKey("TAG_DUMMY_TO_TEST_EXISTENCE"), "storedViewPreferences");
		
		store.setValue(getPreferenceKey(TAG_USER_DEFINED_PATTERNS_ENABLED), fUserDefinedPatternsEnabled);
		store.setValue(getPreferenceKey(TAG_USER_DEFINED_PATTERNS), CustomFiltersDialog.convertToString(fUserDefinedPatterns ,SEPARATOR));
		Iterator iter= fEnabledFilterIds.entrySet().iterator();
		while (iter.hasNext()) {
			Map.Entry entry= (Map.Entry)iter.next();
			String id= (String)entry.getKey();
			boolean isEnabled= ((Boolean)entry.getValue()).booleanValue();
			store.setValue(id, isEnabled);
		}
		StringBuffer buf= new StringBuffer(fLRUFilterIdsStack.size() * 20);
		iter= fLRUFilterIdsStack.iterator();
		while (iter.hasNext()) {
			buf.append((String)iter.next());
			buf.append(SEPARATOR);
		}
		store.setValue(TAG_LRU_FILTERS, buf.toString());
	}
	
	private String getPreferenceKey(String tag) {
		return "CustomFiltersActionGroup." + fTargetId + '.' + tag; 
	}
	
	/**
	 * Saves the state of the custom filters in a memento.
	 * 
	 * @param memento the memento into which the state is saved
	 */
	public void saveState(IMemento memento) {