Separate streaming of QHash and QMultiHash/QMap and QMultiMap

Those classes will not have relations anymore in Qt6, so they need
separate streaming operators. Writing of multi maps/hashes requires some
additional care so that restoring keeps the order of how iteme have been
inserted.

Change-Id: If41d0c5c24962764a2cb81bd2de9e2fadf1a2b63
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/corelib/serialization/qdatastream.h

@@ -296,10 +296,7 @@ QDataStream &readAssociativeContainer(QDataStream &s, Container &c)
             c.clear();
             break;
         }
-QT_WARNING_PUSH
+        c.insert(k, t);
-QT_WARNING_DISABLE_DEPRECATED
-        c.insertMulti(k, t);
-QT_WARNING_POP
     }
 
     return s;
@@ -319,19 +316,20 @@ template <typename Container>
 QDataStream &writeAssociativeContainer(QDataStream &s, const Container &c)
 {
     s << quint32(c.size());
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0) && QT_DEPRECATED_SINCE(5, 15)
+    auto it = c.constBegin();
-    // Deserialization should occur in the reverse order.
+    auto end = c.constEnd();
-    // Otherwise, value() will return the least recently inserted
+    while (it != end) {
-    // value instead of the most recently inserted one.
-    auto it = c.constEnd();
-    auto begin = c.constBegin();
-    while (it != begin) {
-        QT_WARNING_PUSH
-        QT_WARNING_DISABLE_DEPRECATED
-        --it;
-        QT_WARNING_POP
         s << it.key() << it.value();
-#else
+        ++it;
+    }
+
+    return s;
+}
+
+template <typename Container>
+QDataStream &writeAssociativeMultiContainer(QDataStream &s, const Container &c)
+{
+    s << quint32(c.size());
     auto it = c.constBegin();
     auto end = c.constEnd();
     while (it != end) {
@@ -343,7 +341,6 @@ QDataStream &writeAssociativeContainer(QDataStream &s, const Container &c)
             auto next = std::next(rangeStart, i);
             s << next.key() << next.value();
         }
-#endif
     }
 
     return s;
@@ -440,11 +437,24 @@ inline QDataStream &operator>>(QDataStream &s, QHash<Key, T> &hash)
 }
 
 template <class Key, class T>
+
 inline QDataStream &operator<<(QDataStream &s, const QHash<Key, T> &hash)
 {
     return QtPrivate::writeAssociativeContainer(s, hash);
 }
 
+template <class Key, class T>
+inline QDataStream &operator>>(QDataStream &s, QMultiHash<Key, T> &hash)
+{
+    return QtPrivate::readAssociativeContainer(s, hash);
+}
+
+template <class Key, class T>
+inline QDataStream &operator<<(QDataStream &s, const QMultiHash<Key, T> &hash)
+{
+    return QtPrivate::writeAssociativeMultiContainer(s, hash);
+}
+
 template <class Key, class T>
 inline QDataStream &operator>>(QDataStream &s, QMap<Key, T> &map)
 {
@@ -457,6 +467,18 @@ inline QDataStream &operator<<(QDataStream &s, const QMap<Key, T> &map)
     return QtPrivate::writeAssociativeContainer(s, map);
 }
 
+template <class Key, class T>
+inline QDataStream &operator>>(QDataStream &s, QMultiMap<Key, T> &map)
+{
+    return QtPrivate::readAssociativeContainer(s, map);
+}
+
+template <class Key, class T>
+inline QDataStream &operator<<(QDataStream &s, const QMultiMap<Key, T> &map)
+{
+    return QtPrivate::writeAssociativeMultiContainer(s, map);
+}
+
 #ifndef QT_NO_DATASTREAM
 template <class T1, class T2>
 inline QDataStream& operator>>(QDataStream& s, QPair<T1, T2>& p)

tests/auto/corelib/serialization/qdatastream/tst_qdatastream.cpp

@@ -121,6 +121,9 @@ private slots:
     void stream_Map_data();
     void stream_Map();
 
+    void stream_MultiMap_data();
+    void stream_MultiMap();
+
     void stream_Hash_data();
     void stream_Hash();
 
@@ -233,6 +236,7 @@ private:
     void writeQRegularExpression(QDataStream *dev);
 #endif
     void writeMap(QDataStream* dev);
+    void writeMultiMap(QDataStream* dev);
     void writeHash(QDataStream* dev);
     void writeMultiHash(QDataStream* dev);
     void writeqint64(QDataStream *s);
@@ -266,6 +270,7 @@ private:
     void readQRegularExpression(QDataStream *s);
 #endif
     void readMap(QDataStream *s);
+    void readMultiMap(QDataStream *s);
     void readHash(QDataStream *s);
     void readMultiHash(QDataStream *s);
     void readqint64(QDataStream *s);
@@ -655,16 +660,10 @@ static Map MapData(int index)
         map.insert(2, "bbb");
         map.insert(3, "cccccc");
         break;
-    case 2:
-        map.insert(1, "a");
-        map.insert(2, "one");
-        map.insertMulti(2, "two");
-        map.insertMulti(2, "three");
-        map.insert(3, "cccccc");
     }
     return map;
 }
-#define MAX_MAP_DATA 3
+#define MAX_MAP_DATA 2
 
 void tst_QDataStream::stream_Map_data()
 {
@@ -694,6 +693,60 @@ void tst_QDataStream::readMap(QDataStream *s)
     QCOMPARE(S, test);
 }
 
+typedef QMultiMap<int, QString> MultiMap;
+
+static MultiMap MultiMapData(int index)
+{
+    MultiMap map;
+
+    switch (index) {
+    case 0:
+    default:
+        break;
+    case 1:
+        map.insert(1, "a");
+        map.insert(2, "bbb");
+        map.insert(3, "cccccc");
+        break;
+    case 2:
+        map.insert(1, "a");
+        map.insert(2, "one");
+        map.insert(2, "two");
+        map.insert(2, "three");
+        map.insert(3, "cccccc");
+    }
+    return map;
+}
+#define MAX_MULTIMAP_DATA 3
+
+void tst_QDataStream::stream_MultiMap_data()
+{
+    stream_data(MAX_MULTIMAP_DATA);
+}
+
+void tst_QDataStream::stream_MultiMap()
+{
+    STREAM_IMPL(MultiMap);
+}
+
+void tst_QDataStream::writeMultiMap(QDataStream* s)
+{
+    MultiMap test(MultiMapData(dataIndex(QTest::currentDataTag())));
+    *s << test;
+    *s << test;
+}
+
+void tst_QDataStream::readMultiMap(QDataStream *s)
+{
+    MultiMap S;
+    MultiMap test(MultiMapData(dataIndex(QTest::currentDataTag())));
+
+    *s >> S;
+    QCOMPARE(S, test);
+    *s >> S;
+    QCOMPARE(S, test);
+}
+
 // ************************************
 
 typedef QHash<int, QString> Hash;