diff -r 41300fa6a67c -r f7bc934e204c tests/auto/qhostinfo/tst_qhostinfo.cpp
--- a/tests/auto/qhostinfo/tst_qhostinfo.cpp	Tue Feb 02 00:43:10 2010 +0200
+++ b/tests/auto/qhostinfo/tst_qhostinfo.cpp	Wed Mar 31 11:06:36 2010 +0300
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
@@ -72,6 +72,7 @@
 #endif
 
 #include <qhostinfo.h>
+#include "private/qhostinfo_p.h"
 
 #if !defined(QT_NO_GETADDRINFO)
 # if !defined(Q_OS_WINCE)
@@ -108,10 +109,11 @@
 public slots:
     void init();
     void cleanup();
+    void initTestCase();
+
 private slots:
     void getSetCheck();
     void staticInformation();
-    void initTestCase();
     void lookupIPv4_data();
     void lookupIPv4();
     void lookupIPv6_data();
@@ -128,6 +130,8 @@
     void multipleSameLookups();
     void multipleDifferentLookups();
 
+    void cache();
+
 protected slots:
     void resultsReady(const QHostInfo &);
 
@@ -205,10 +209,21 @@
         // We have IPv6 support
         ipv6Available = true;
     }
+
+
+    // run each testcase with and without test enabled
+    QTest::addColumn<bool>("cache");
+    QTest::newRow("WithCache") << true;
+    QTest::newRow("WithoutCache") << false;
 }
 
 void tst_QHostInfo::init()
 {
+    // delete the cache so inidividual testcase results are independant from each other
+    qt_qhostinfo_clear_cache();
+
+    QFETCH_GLOBAL(bool, cache);
+    qt_qhostinfo_enable_cache(cache);
 }
 
 void tst_QHostInfo::cleanup()
@@ -458,6 +473,45 @@
     QTRY_VERIFY(lookupsDoneCounter == COUNT);
 }
 
+void tst_QHostInfo::cache()
+{
+    QFETCH_GLOBAL(bool, cache);
+    if (!cache)
+        return; // test makes only sense when cache enabled
+
+    // reset slot counter
+    lookupsDoneCounter = 0;
+
+    // lookup once, wait in event loop, result should not come directly.
+    bool valid = true;
+    int id = -1;
+    QHostInfo result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid, &id);
+    QTestEventLoop::instance().enterLoop(5);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+    QVERIFY(valid == false);
+    QVERIFY(result.addresses().isEmpty());
+
+    // loopkup second time, result should come directly
+    valid = false;
+    result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid, &id);
+    QVERIFY(valid == true);
+    QVERIFY(!result.addresses().isEmpty());
+
+    // clear the cache
+    qt_qhostinfo_clear_cache();
+
+    // lookup third time, result should not come directly.
+    valid = true;
+    result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid, &id);
+    QTestEventLoop::instance().enterLoop(5);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+    QVERIFY(valid == false);
+    QVERIFY(result.addresses().isEmpty());
+
+    // the slot should have been called 2 times.
+    QVERIFY(lookupsDoneCounter == 2);
+}
+
 void tst_QHostInfo::resultsReady(const QHostInfo &hi)
 {
     lookupDone = true;