JAVA-497: read preference set on mongo options was not getting applied to Mongo instance

Author: jyemin

src/main/com/mongodb/Mongo.java

@@ -565,8 +565,13 @@ public int getOptions(){
      */
     @SuppressWarnings("deprecation")
     void _applyMongoOptions() {
-        if (_options.slaveOk) slaveOk();
-        setWriteConcern( _options.getWriteConcern() );
+        if (_options.slaveOk) {
+            slaveOk();
+        }
+        if (_options.getReadPreference() != null) {
+           setReadPreference(_options.getReadPreference());
+        }
+        setWriteConcern(_options.getWriteConcern());
     }
 
     /**

src/test/com/mongodb/MongoTest.java

@@ -24,6 +24,7 @@
 import org.testng.annotations.Test;
 
 import java.io.IOException;
+import java.net.UnknownHostException;
 
 public class MongoTest extends TestCase {
 
@@ -53,6 +54,31 @@ public void testClose_shouldNotReturnUntilCleanupThreadIsFinished() throws Excep
         assertFalse(mongo._cleaner.isAlive());
     }
 
+    @SuppressWarnings("deprecation")
+    @Test
+    public void testApplyOptions() throws UnknownHostException {
+        MongoOptions options = new MongoOptions();
+
+        // test defaults
+        Mongo m = new Mongo("localhost", options);
+        assertEquals(ReadPreference.primary(), m.getReadPreference());
+        assertEquals(WriteConcern.NORMAL, m.getWriteConcern());
+        assertEquals(0, m.getOptions() & Bytes.QUERYOPTION_SLAVEOK);
+        m.close();
+
+        // test setting options
+        options.setReadPreference(ReadPreference.nearest());
+        options.slaveOk = true;
+        options.safe = true;
+
+        m = new Mongo("localhost", options);
+        assertEquals(ReadPreference.nearest(), m.getReadPreference());
+        assertEquals(WriteConcern.SAFE, m.getWriteConcern());
+        assertEquals(Bytes.QUERYOPTION_SLAVEOK, m.getOptions() & Bytes.QUERYOPTION_SLAVEOK);
+        m.close();
+
+    }
+
     @AfterTest
     public void tearDown() {
         Mongo.cleanerIntervalMS = _originalCleanerIntervalMs;