Fix qHash(QMultiHash)

The old code was trying to convert a multi hash to a QHash. While
that worked in Qt 5 it won't compile in Qt 6 anymore.

QHashCombineCommutative also can't be used with a std::pair.
ADL won't find the correct instance with a namespaced build,
as qHash(std::pair) is defined after QHashCommutative. Fix
the code to compile and work correctly.

Change-Id: Ice2bc3ab4244e310cbbb5e0f31fc11eb14f5faf3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/auto/corelib/tools/qhash/tst_qhash.cpp b/tests/auto/corelib/tools/qhash/tst_qhash.cpp
index d5a8db7553..d63ed7043e 100644
--- a/tests/auto/corelib/tools/qhash/tst_qhash.cpp
+++ b/tests/auto/corelib/tools/qhash/tst_qhash.cpp
@@ -73,6 +73,7 @@ private slots:
     void emplace();
 
     void badHashFunction();
+    void hashOfHash();
 };
 
 struct IdentityTracker {
@@ -1754,5 +1755,14 @@ void tst_QHash::badHashFunction()
 
 }
 
+void tst_QHash::hashOfHash()
+{
+    QHash<int, int> hash;
+    (void)qHash(hash);
+
+    QMultiHash<int, int> multiHash;
+    (void)qHash(multiHash);
+}
+
 QTEST_APPLESS_MAIN(tst_QHash)
 #include "tst_qhash.moc"