From cad69a751659cbe32af4ff6e0ddcf01b313bf8c0 Mon Sep 17 00:00:00 2001
From: Mark Raynsford <code@io7m.com>
Date: Thu, 21 May 2015 16:34:18 +0000
Subject: [PATCH] Do not assume that if an argument bundle exists at all, then
 it must contain catalog stacks

---
 .../org/nypl/simplified/app/catalog/CatalogActivity.java  | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/simplified-app/src/main/java/org/nypl/simplified/app/catalog/CatalogActivity.java b/simplified-app/src/main/java/org/nypl/simplified/app/catalog/CatalogActivity.java
index d42f898c8..83e899433 100644
--- a/simplified-app/src/main/java/org/nypl/simplified/app/catalog/CatalogActivity.java
+++ b/simplified-app/src/main/java/org/nypl/simplified/app/catalog/CatalogActivity.java
@@ -62,8 +62,12 @@ private void configureUpButton(
     final Intent i = NullCheck.notNull(this.getIntent());
     final Bundle a = i.getExtras();
     if (a != null) {
-      return (ImmutableStack<CatalogUpStackEntry>) NullCheck.notNull(a
-        .getSerializable(CatalogActivity.CATALOG_UP_STACK_ID));
+      final ImmutableStack<CatalogUpStackEntry> stack =
+        (ImmutableStack<CatalogUpStackEntry>) a
+          .getSerializable(CatalogActivity.CATALOG_UP_STACK_ID);
+      if (stack != null) {
+        return stack;
+      }
     }
 
     final ImmutableStack<CatalogUpStackEntry> empty = ImmutableStack.empty();