QDomNodeList: port to compare helpers

Just this one, for now, as an example, and to establish QtXml's
removed_api.cpp.

The QDomNode hierarchy will follow in a subsequent patch.

Task-number: QTBUG-130846
Change-Id: Ib095481cc57471b303cd8251194488d9875edcfb
Reviewed-by: Ivan Solovev <[email protected]>

6 files changed, 118 insertions, 10 deletions

diff --git a/src/xml/CMakeLists.txt b/src/xml/CMakeLists.txt
index 65e13db7e7e..ef73bbc7e29 100644
--- a/src/xml/CMakeLists.txt
+++ b/src/xml/CMakeLists.txt
@@ -23,8 +23,11 @@ qt_internal_add_module(Xml
 
 qt_internal_extend_target(Xml CONDITION QT_FEATURE_dom
     SOURCES
+        compat/removed_api.cpp
         dom/qdom.cpp dom/qdom.h dom/qdom_p.h
         dom/qdomhelpers.cpp dom/qdomhelpers_p.h
+    NO_PCH_SOURCES
+        compat/removed_api.cpp
 )
 
 qt_internal_extend_target(Xml CONDITION MSVC AND (TEST_architecture_arch STREQUAL "i386")
diff --git a/src/xml/compat/removed_api.cpp b/src/xml/compat/removed_api.cpp
new file mode 100644
index 00000000000..6214a5b3bd3
--- /dev/null
+++ b/src/xml/compat/removed_api.cpp
@@ -0,0 +1,32 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#define QT_XML_BUILD_REMOVED_API
+
+#include "qtxmlglobal.h"
+
+QT_USE_NAMESPACE
+
+#if QT_XML_REMOVED_SINCE(6, 9)
+
+#if QT_CONFIG(dom)
+
+#include "qdom.h"
+
+bool QDomNodeList::operator==(const QDomNodeList &other) const
+{
+    return comparesEqual(*this, other);
+}
+
+bool QDomNodeList::operator!=(const QDomNodeList &other) const
+{
+    return !comparesEqual(*this, other);
+}
+
+#endif // QT_CONFIG(dom)
+
+// #include <qotherheader.h>
+// // implement removed functions from qotherheader.h
+// order sections alphabetically to reduce chances of merge conflicts
+
+#endif // QT_XML_REMOVED_SINCE(6, 9)
diff --git a/src/xml/dom/qdom.cpp b/src/xml/dom/qdom.cpp
index 64f32030c87..d7c3eb25868 100644
--- a/src/xml/dom/qdom.cpp
+++ b/src/xml/dom/qdom.cpp
@@ -794,26 +794,26 @@ QDomNodeList& QDomNodeList::operator=(const QDomNodeList &other)
 }
 
 /*!
-    Returns \c true if the node list \a other and this node list are equal;
+    \fn bool QDomNodeList::operator==(const QDomNodeList &lhs, const QDomNodeList &rhs)
+
+    Returns \c true if the node lists \a lhs and \a rhs are equal;
     otherwise returns \c false.
 */
-bool QDomNodeList::operator==(const QDomNodeList &other) const
+bool comparesEqual(const QDomNodeList &lhs, const QDomNodeList &rhs) noexcept
 {
-    if (impl == other.impl)
+    if (lhs.impl == rhs.impl)
         return true;
-    if (!impl || !other.impl)
+    if (!lhs.impl || !rhs.impl)
         return false;
-    return (*impl == *other.impl);
+    return *lhs.impl == *rhs.impl;
 }
 
 /*!
-    Returns \c true the node list \a other and this node list are not equal;
+    \fn bool QDomNodeList::operator!=(const QDomNodeList &lhs, const QDomNodeList &rhs)
+
+    Returns \c true if the node lists \a lhs and \a rhs are not equal;
     otherwise returns \c false.
 */
-bool QDomNodeList::operator!=(const QDomNodeList &other) const
-{
-    return !operator==(other);
-}
 
 /*!
     Destroys the object and frees its resources.
diff --git a/src/xml/dom/qdom.h b/src/xml/dom/qdom.h
index 0ac7d9130e9..22a8f41d8ca 100644
--- a/src/xml/dom/qdom.h
+++ b/src/xml/dom/qdom.h
@@ -5,6 +5,8 @@
 #define QDOM_H
 
 #include <QtXml/qtxmlglobal.h>
+
+#include <QtCore/qcompare.h>
 #include <QtCore/qstring.h>
 
 #if QT_CONFIG(dom)
@@ -215,8 +217,10 @@ public:
     QDomNodeList();
     QDomNodeList(const QDomNodeList &nodeList);
     QDomNodeList& operator=(const QDomNodeList &other);
+#if QT_XML_REMOVED_SINCE(6, 9)
     bool operator==(const QDomNodeList &other) const;
     bool operator!=(const QDomNodeList &other) const;
+#endif
     ~QDomNodeList();
 
     // DOM functions
@@ -230,6 +234,10 @@ public:
     inline bool isEmpty() const { return length() == 0; } // Qt API consistency
 
 private:
+    Q_XML_EXPORT friend bool comparesEqual(const QDomNodeList &lhs, const QDomNodeList &rhs) noexcept;
+    Q_DECLARE_EQUALITY_COMPARABLE(QDomNodeList)
+
+private:
     QDomNodeListPrivate* impl;
     QDomNodeList(QDomNodeListPrivate*);
 
diff --git a/tests/auto/xml/dom/qdom/CMakeLists.txt b/tests/auto/xml/dom/qdom/CMakeLists.txt
index 4eea988cc32..f3c448f9c7f 100644
--- a/tests/auto/xml/dom/qdom/CMakeLists.txt
+++ b/tests/auto/xml/dom/qdom/CMakeLists.txt
@@ -25,5 +25,6 @@ qt_internal_add_test(tst_qdom
     LIBRARIES
         Qt::Xml
         Qt::XmlPrivate
+        Qt::TestPrivate
     TESTDATA ${test_data}
 )
diff --git a/tests/auto/xml/dom/qdom/tst_qdom.cpp b/tests/auto/xml/dom/qdom/tst_qdom.cpp
index 3a6fc1356c3..a224b004117 100644
--- a/tests/auto/xml/dom/qdom/tst_qdom.cpp
+++ b/tests/auto/xml/dom/qdom/tst_qdom.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
 #include <QtTest/qtest.h>
+#include <QtTest/private/qcomparisontesthelper_p.h>
 
 #include <QtXml/qdom.h>
 
@@ -115,6 +116,10 @@ private slots:
     void standalone();
     void splitTextLeakMemory() const;
 
+    void testDomListComparisonCompiles();
+    void testDomListComparison_data();
+    void testDomListComparison();
+
     void cleanupTestCase() const;
 
 private:
@@ -2337,5 +2342,64 @@ void tst_QDom::splitTextLeakMemory() const
     QCOMPARE(end.impl->ref.loadRelaxed(), 2);
 }
 
+void tst_QDom::testDomListComparisonCompiles()
+{
+    QTestPrivate::testEqualityOperatorsCompile<QDomNodeList>();
+}
+
+static QDomElement findElementByName(const QDomDocument &doc, QLatin1StringView tag)
+{
+    const auto list = doc.elementsByTagName(tag);
+#ifdef QTEST_THROW_ON_FAIL
+    QCOMPARE(list.size(), 1);
+    QCOMPARE(list.at(0).nodeType(), QDomNode::NodeType::ElementNode);
+#endif
+    return list.at(0).toElement();
+}
+
+void tst_QDom::testDomListComparison_data()
+{
+    QTest::addColumn<QDomDocument>("doc");
+    QTest::addColumn<QDomNodeList>("lhs");
+    QTest::addColumn<QDomNodeList>("rhs");
+    QTest::addColumn<bool>("result");
+
+    const auto xml = "<top><child1/><child2/><child3><cchild1/><cchild2/></child3></top>"_L1;
+
+    QDomDocument doc;
+    const auto result = doc.setContent(xml);
+    QVERIFY2(result, result.errorMessage.toLocal8Bit().constData());
+
+    const QDomNodeList null;
+    const QDomNodeList empty = findElementByName(doc, "child1"_L1).childNodes();
+    const QDomNodeList child3Children = findElementByName(doc, "child3"_L1).childNodes();
+    const QDomNodeList topChildren = findElementByName(doc, "top"_L1).childNodes();
+
+#define ROW(lhs, rhs, res) \
+    QTest::addRow("%s <> %s", #lhs, #rhs) << doc << lhs << rhs << bool(res)
+
+    ROW(null, null, true);
+    ROW(empty, empty, true);
+    ROW(child3Children, child3Children, true);
+    ROW(topChildren, topChildren, true);
+
+    ROW(null, empty, false);
+    ROW(empty, child3Children, false);
+    ROW(child3Children, topChildren, false);
+    ROW(topChildren, null, false);
+#undef ROW
+}
+
+void tst_QDom::testDomListComparison()
+{
+    [[maybe_unused]]
+    QFETCH(const QDomDocument, doc);
+    QFETCH(const QDomNodeList, lhs);
+    QFETCH(const QDomNodeList, rhs);
+    QFETCH(const bool, result);
+
+    QT_TEST_EQUALITY_OPS(lhs, rhs, result);
+}
+
 QTEST_MAIN(tst_QDom)
 #include "tst_qdom.moc"