Fix bugs around inconsistent locale

libraries/bot-builder/src/main/java/com/microsoft/bot/builder/BotAdapter.java

@@ -10,6 +10,7 @@
 import com.microsoft.bot.schema.ResourceResponse;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 import org.apache.commons.lang3.NotImplementedException;
@@ -196,6 +197,9 @@ protected CompletableFuture<Void> runPipeline(
         // Call any registered Middleware Components looking for ReceiveActivity()
         if (context.getActivity() != null) {
             if (!StringUtils.isEmpty(context.getActivity().getLocale())) {
+
+                Locale.setDefault(Locale.forLanguageTag(context.getActivity().getLocale()));
+
                 context.setLocale(context.getActivity().getLocale());
             }
 

libraries/bot-builder/src/main/java/com/microsoft/bot/builder/TurnContext.java

@@ -24,6 +24,8 @@
  * {@link Bot} {@link Middleware}
  */
 public interface TurnContext {
+    String STATE_TURN_LOCALE = "turn.locale";
+
     /**
      * Sends a trace activity to the {@link BotAdapter} for logging purposes.
      *

libraries/bot-builder/src/main/java/com/microsoft/bot/builder/TurnContextImpl.java

@@ -67,8 +67,6 @@ public class TurnContextImpl implements TurnContext, AutoCloseable {
      */
     private Boolean responded = false;
 
-    private static final String STATE_TURN_LOCALE = "turn.locale";
-
     /**
      * Creates a context object.
      *

libraries/bot-builder/src/test/java/com/microsoft/bot/builder/BotAdapterTests.java

@@ -47,6 +47,27 @@ public void PassResourceResponsesThrough() {
         );
     }
 
+    @Test
+    public void GetLocaleFromActivity() {
+        Consumer<List<Activity>> validateResponse = (activities) -> {
+            // no need to do anything.
+        };
+        SimpleAdapter a = new SimpleAdapter(validateResponse);
+        TurnContextImpl c = new TurnContextImpl(a, new Activity(ActivityTypes.MESSAGE));
+
+        String activityId = UUID.randomUUID().toString();
+        Activity activity = TestMessage.Message();
+        activity.setId(activityId);
+        activity.setLocale("de-DE");
+        BotCallbackHandler callback = (turnContext) -> {
+            Assert.assertEquals("de-DE", turnContext.getActivity().getLocale());
+            return CompletableFuture.completedFuture(null);
+        };
+
+        a.processRequest(activity, callback).join();
+    }
+
+
     @Test
     public void ContinueConversation_DirectMsgAsync() {
         boolean[] callbackInvoked = new boolean[] { false };

libraries/bot-dialogs/src/main/java/com/microsoft/bot/dialogs/DialogContext.java

@@ -10,6 +10,7 @@
 import com.microsoft.bot.connector.Async;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.concurrent.CompletableFuture;
 import org.apache.commons.lang3.StringUtils;
 
@@ -529,13 +530,24 @@ public CompletableFuture<Boolean> emitEvent(String name, Object value, boolean b
     }
 
     /**
-     * Obtain the CultureInfo in DialogContext.
+     * Obtain the locale in DialogContext.
      * @return A String representing the current locale.
      */
     public String getLocale() {
-        return getContext() != null ? getContext().getLocale() : null;
-    }
+        // turn.locale is the highest precedence.
+        String locale = (String) state.get(TurnContext.STATE_TURN_LOCALE);
+        if (!StringUtils.isEmpty(locale)) {
+            return locale;
+        }
+
+        // If turn.locale was not populated, fall back to activity locale
+        locale = getContext().getActivity().getLocale();
+        if (!StringUtils.isEmpty(locale)) {
+            return locale;
+        }
 
+        return Locale.getDefault().toString();
+    }
 
     /**
      * @param reason
@@ -545,7 +557,6 @@ private CompletableFuture<Void> endActiveDialog(DialogReason reason) {
         return endActiveDialog(reason, null);
     }
 
-
     /**
      * @param reason
      * @param result