Added test from pull request #429.

src/test/java/redis/clients/jedis/tests/JedisPoolTest.java

@@ -150,4 +150,24 @@ public class JedisPoolTest extends Assert {
 	assertEquals("PONG", jedis.ping());
 	assertEquals("bar", jedis.get("foo"));
     }
+
+	@Test
+	public void selectDatabaseOnActivation() {
+		JedisPool pool = new JedisPool(new JedisPoolConfig(), hnp.host, hnp.port, 2000, "foobared");
+
+		Jedis jedis0 = pool.getResource();
+		assertEquals(0L, jedis0.getDB().longValue());
+		
+		jedis0.select(1);
+		assertEquals(1L, jedis0.getDB().longValue());
+
+		pool.returnResource(jedis0);
+
+		Jedis jedis1 = pool.getResource();
+		assertTrue("Jedis instance was not reused", jedis1	== jedis0);
+		assertEquals(0L, jedis1.getDB().longValue());
+
+		pool.returnResource(jedis1);
+		pool.destroy();
+	}
 }