Don't show spinner popup if adapter is null

BUG: 10076106
Change-Id: I1c1c235645b7963f802b0747f7ca64d8aedaaa66
diff --git a/core/java/android/widget/Spinner.java b/core/java/android/widget/Spinner.java
index 789d263..eec15a9 100644
--- a/core/java/android/widget/Spinner.java
+++ b/core/java/android/widget/Spinner.java
@@ -937,6 +937,9 @@
         }
 
         public void show(int textDirection, int textAlignment) {
+            if (mListAdapter == null) {
+                return;
+            }
             AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
             if (mPrompt != null) {
                 builder.setTitle(mPrompt);