Decode not called for all UIComponents in tree

Question

Many of the faces .jsp pages I have been working with in EA2 have not been updating their models properly.
The symptom I have observed is that the decode method is not called for all of the UIComponents on the page.
I think I have tracked this down to a bug in the class com.sun.faces.tree.TreeNavigatorImpl. This class appears to be used internally by some of the .jsf code to navigate the component tree.
Studying various stack traces, it looks like the method TreeNavigatorImpl.getNextStart() is supposed to provide a preorder traversal of the component tree. Starting from the root of the tree, each call is expected to return the next node. Experimental evidence suggests that it is not doing that properly, and it fails to visit all the nodes in the tree.
For example, if my component tree looks like this (this is a representation of the tree; not an example of a .jsp page):
<node id = "/">
   <node id = "page">
      <node id = "carStoreForm">
         <node id = "ba0">
             <node id = "ba1">
                 <node id = "ba3"/>
                 <node id = "br4"/>
             </node>
         </node>
         <node id = "bold1"/>
         <node id = "more1"/>
      </node>
   </node>
</node>A preorder traversal of these nodes should visit nodes:
'/page'
'/page/carStoreForm'
'/page/carStoreForm/ba0'
'/page/carStoreForm/ba0/ba1'
'/page/carStoreForm/ba0/ba1/ba3'
'/page/carStoreForm/ba0/ba1/br4'
'/page/carStoreForm/bold1'
'/page/carStoreForm/more1'
However, when I write test code that calls TreeNavigatorImpl.getNextStart() directly, only the following nodes are returned:
'/page'
'/page/carStoreForm'
'/page/carStoreForm/ba0'
'/page/carStoreForm/ba0/ba1'
'/page/carStoreForm/ba0/ba1/ba3'
'/page/carStoreForm/ba0/ba1/br4'
It looks to me like the method loses track of the state of the traversal, and prematurely returns null before all the nodes are visited. (It is failing to return the "bold1" and "more1" nodes.)
This is all extremely speculative. Without jsf source or doc for any of the tree classes, it is difficult to know what is supposed to be going on. And, of course, I may just have a bug in my code.

Answer 1

Okay, rather than wait for Max to respond, I decompiled the TreeNavigatorImpl class myself and studied the source code. The
problem arises in the getNextStart() method. If the method returns
a null value, then presumably the class has successfully traversed
the entire tree in preorder. Unfortunately, there was a slight
logic error that would halt traversal after you got to the last node
of the last subtree at the beginning of your travels.
The following code should correct this situation (let me know if I've
introduced any new problems into the mix...). I tested this out using the simple example that Max describes above. The test code appears at the end of my revised method:
public UIComponent getNextStart() {
UIComponent cur = null;
if (startTraversalDone) {
return cur;
if (startStack.empty()) {
cur = root;
Iterator iter = cur.getChildren();
if (iter.hasNext()) {
startStack.push(iter);
else {
while (!startStack.empty()) {
     Iterator iter = (Iterator) startStack.peek();
     if (iter != null && iter.hasNext()) {
     cur = (UIComponent) iter.next();
     Iterator childIter = cur.getChildren();
     if (childIter != null && childIter.hasNext()) {
     startStack.push(childIter);
     else {
     if (!iter.hasNext()) {
     startStack.pop();
     break;
else {
     startStack.pop();
if (startStack.empty()) {
startTraversalDone = true;
if (cur != null) {
endStack.push(cur);
return cur;
     public static void main(String[] args) {
          MyComp root = new MyComp("root");
          // build tree....
          MyComp page = new MyComp("page");
          root.addChild(page);
          MyComp csf = new MyComp("csf");
          page.addChild(csf);
          MyComp ba0 = new MyComp("ba0");
          csf.addChild(ba0);
          csf.addChild(new MyComp("bold1"));
          csf.addChild(new MyComp("more1"));
          MyComp ba1 = new MyComp("ba1");
          ba0.addChild(ba1);
          ba1.addChild(new MyComp("ba3"));
          ba1.addChild(new MyComp("ba4"));
          MyTreeNavigator nav = new MyTreeNavigator(root);
          MyComp comp = null;
          while ((comp = (MyComp) nav.getNextStart()) != null) {
               System.out.println(comp.getComponentId());
public class MyComp extends UIComponentBase {
     public MyComp(String id) {
          this.setComponentId(id);
     public String getComponentType() {
          return "MyComp";