4 files changed, 56 insertions, 20 deletions

diff --git a/src/corelib/kernel/qmetaobjectbuilder.cpp b/src/corelib/kernel/qmetaobjectbuilder.cpp
index 4518d702cd..11ab39af1a 100644
--- a/src/corelib/kernel/qmetaobjectbuilder.cpp
+++ b/src/corelib/kernel/qmetaobjectbuilder.cpp
@@ -1075,8 +1075,14 @@ int QMetaObjectBuilder::indexOfClassInfo(const QByteArray& name)
     \brief The QMetaStringTable class can generate a meta-object string table at runtime.
 */
 
-QMetaStringTable::QMetaStringTable()
-    : m_index(0) {}
+QMetaStringTable::QMetaStringTable(const QByteArray &className)
+    : m_index(0)
+    , m_className(className)
+{
+    const int index = enter(m_className);
+    Q_ASSERT(index == 0);
+    Q_UNUSED(index);
+}
 
 // Enters the given value into the string table (if it hasn't already been
 // entered). Returns the index of the string.
@@ -1106,30 +1112,45 @@ int QMetaStringTable::blobSize() const
     return size;
 }
 
+static void writeString(char *out, int i, const QByteArray &str,
+                        const int offsetOfStringdataMember, int &stringdataOffset)
+{
+    int size = str.size();
+    qptrdiff offset = offsetOfStringdataMember + stringdataOffset
+            - i * sizeof(QByteArrayData);
+    const QByteArrayData data =
+        Q_STATIC_BYTE_ARRAY_DATA_HEADER_INITIALIZER_WITH_OFFSET(size, offset);
+
+    memcpy(out + i * sizeof(QByteArrayData), &data, sizeof(QByteArrayData));
+
+    memcpy(out + offsetOfStringdataMember + stringdataOffset, str.constData(), size);
+    out[offsetOfStringdataMember + stringdataOffset + size] = '\0';
+
+    stringdataOffset += size + 1;
+}
+
 // Writes strings to string data struct.
 // The struct consists of an array of QByteArrayData, followed by a char array
 // containing the actual strings. This format must match the one produced by
 // moc (see generator.cpp).
-void QMetaStringTable::writeBlob(char *out)
+void QMetaStringTable::writeBlob(char *out) const
 {
     Q_ASSERT(!(reinterpret_cast<quintptr>(out) & (preferredAlignment()-1)));
 
     int offsetOfStringdataMember = m_entries.size() * sizeof(QByteArrayData);
     int stringdataOffset = 0;
-    for (int i = 0; i < m_entries.size(); ++i) {
-        const QByteArray &str = m_entries.key(i);
-        int size = str.size();
-        qptrdiff offset = offsetOfStringdataMember + stringdataOffset
-                - i * sizeof(QByteArrayData);
-        const QByteArrayData data =
-            Q_STATIC_BYTE_ARRAY_DATA_HEADER_INITIALIZER_WITH_OFFSET(size, offset);
 
-        memcpy(out + i * sizeof(QByteArrayData), &data, sizeof(QByteArrayData));
+    // qt_metacast expects the first string in the string table to be the class name.
+    writeString(out, /*index*/0, m_className, offsetOfStringdataMember, stringdataOffset);
 
-        memcpy(out + offsetOfStringdataMember + stringdataOffset, str.constData(), size);
-        out[offsetOfStringdataMember + stringdataOffset + size] = '\0';
+    for (Entries::ConstIterator it = m_entries.constBegin(), end = m_entries.constEnd();
+         it != end; ++it) {
+        const int i = it.value();
+        if (i == 0)
+            continue;
+        const QByteArray &str = it.key();
 
-        stringdataOffset += size + 1;
+        writeString(out, i, str, offsetOfStringdataMember, stringdataOffset);
     }
 }
 
@@ -1270,8 +1291,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
     // Reset the current data position to just past the QMetaObjectPrivate.
     dataIndex = MetaObjectPrivateFieldCount;
 
-    QMetaStringTable strings;
-    strings.enter(d->className);
+    QMetaStringTable strings(d->className);
 
     // Output the class infos,
     Q_ASSERT(!buf || dataIndex == pmeta->classInfoData);
diff --git a/src/corelib/kernel/qmetaobjectbuilder_p.h b/src/corelib/kernel/qmetaobjectbuilder_p.h
index f79ce2f2f1..110aaf9ce2 100644
--- a/src/corelib/kernel/qmetaobjectbuilder_p.h
+++ b/src/corelib/kernel/qmetaobjectbuilder_p.h
@@ -323,18 +323,19 @@ private:
 class Q_CORE_EXPORT QMetaStringTable
 {
 public:
-    QMetaStringTable();
+    QMetaStringTable(const QByteArray &className);
 
     int enter(const QByteArray &value);
 
     static int preferredAlignment();
     int blobSize() const;
-    void writeBlob(char *out);
+    void writeBlob(char *out) const;
 
 private:
     typedef QHash<QByteArray, int> Entries; // string --> index mapping
     Entries m_entries;
     int m_index;
+    QByteArray m_className;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QMetaObjectBuilder::AddMembers)
diff --git a/src/dbus/qdbusmetaobject.cpp b/src/dbus/qdbusmetaobject.cpp
index 51c0b27668..13c538bb59 100644
--- a/src/dbus/qdbusmetaobject.cpp
+++ b/src/dbus/qdbusmetaobject.cpp
@@ -445,8 +445,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
         data_size += 2 + mm.inputTypes.count() + mm.outputTypes.count();
     idata.resize(data_size + 1);
 
-    QMetaStringTable strings;
-    strings.enter(className.toLatin1());
+    QMetaStringTable strings(className.toLatin1());
 
     int offset = header->methodData;
     int parametersOffset = offset + header->methodCount * 5;
diff --git a/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp b/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
index 8f6bd50cca..5cf3e6d97c 100644
--- a/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
+++ b/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
@@ -75,6 +75,8 @@ private slots:
     void usage_connect();
     void usage_templateConnect();
 
+    void classNameFirstInStringData();
+
 private:
     static bool checkForSideEffects
         (const QMetaObjectBuilder& builder,
@@ -1694,6 +1696,20 @@ void tst_QMetaObjectBuilder::usage_templateConnect()
     QVERIFY(!con);
 }
 
+void tst_QMetaObjectBuilder::classNameFirstInStringData()
+{
+    QMetaObjectBuilder builder;
+    builder.addMetaObject(&SomethingOfEverything::staticMetaObject);
+    builder.setClassName(QByteArrayLiteral("TestClass"));
+    QMetaObject *mo = builder.toMetaObject();
+
+    QByteArrayDataPtr header;
+    header.ptr = const_cast<QByteArrayData*>(mo->d.stringdata);
+    QCOMPARE(QByteArray(header), QByteArrayLiteral("TestClass"));
+
+    free(mo);
+}
+
 QTEST_MAIN(tst_QMetaObjectBuilder)
 
 #include "tst_qmetaobjectbuilder.moc"