commit 2cd10ba2ef977cca5231ce59bd1130162b4a5db8
author Roberto Lublinerman <rluble@google.com> Wed Sep 30 12:33:57 2015 -0700
committer Ray Cromwell <cromwellian@google.com> Mon Oct 05 15:50:00 2015 -0700
tree 8d271df06adb63a62a6528abdda7758f96e868ec
parent c712422adc04f0dbf9690a3706586979002b5190

Fix NPE in AsyncFragmentLoader for 'already loaded' fragments.

AsyncFragmentLoader makes the assumption that fragment loads are always
initiated by runAsync() call, however Inbox uses an 'already downloaded'
download strategy whereby a server-side linker concatenates needed modules to
be preloaded onto the output. This means the onLoad() call is invoked without
a corresponding startFragment call.

This mostly works, except for the leftovers fragment, wherein a queue variable
is lazily initialized and deferenced early.

Change-Id: Id057ed61c50de12eeea8d0ac4a02c3dcc826103e

user/src/com/google/gwt/core/client/impl/AsyncFragmentLoader.java

diff --git a/user/src/com/google/gwt/core/client/impl/AsyncFragmentLoader.java b/user/src/com/google/gwt/core/client/impl/AsyncFragmentLoader.java
index 0011be6..8c7528b 100644
--- a/user/src/com/google/gwt/core/client/impl/AsyncFragmentLoader.java
+++ b/user/src/com/google/gwt/core/client/impl/AsyncFragmentLoader.java
@@ -424,7 +424,12 @@
       pendingDownloadErrorHandlers[fragment] = null;
     }
 
-    if (isInitial(fragment)) {
+    /**
+     * It is possible for a fragment to be preloaded by the linker or server before runAsync() has
+     * requested it, in this case the leftovers fragment will be have it's onLoad() called before
+     * remainingInitialFragments has been initialized.
+     */
+    if (isInitial(fragment) && remainingInitialFragments != null) {
       assert (fragment == remainingInitialFragments.peek());
       remainingInitialFragments.remove();
     }