6 files changed, 335 insertions, 29 deletions
diff --git a/src/tools/uic/cpp/cppwriteinitialization.cpp b/src/tools/uic/cpp/cppwriteinitialization.cpp
index c1e3e98f43b..893cc5b8ecd 100644
--- a/src/tools/uic/cpp/cppwriteinitialization.cpp
+++ b/src/tools/uic/cpp/cppwriteinitialization.cpp
@@ -2698,10 +2698,6 @@ ConnectionSyntax WriteInitialization::connectionSyntax(const language::SignalSlo
         return ConnectionSyntax::StringBased;
     }
 
-    // QTBUG-110952, ambiguous overloads of display()
-    if (receiver.className == u"QLCDNumber" && receiver.signature.startsWith(u"display("))
-        return ConnectionSyntax::StringBased;
-
     if ((sender.name == m_mainFormVarName && m_customSignals.contains(sender.signature))
          || (receiver.name == m_mainFormVarName && m_customSlots.contains(receiver.signature))) {
         return ConnectionSyntax::StringBased;
@@ -2729,14 +2725,21 @@ void WriteInitialization::acceptConnection(DomConnection *connection)
         return;
     }
     const QString senderSignature = connection->elementSignal();
+    const QString slotSignature = connection->elementSlot();
+    const bool senderAmbiguous = m_uic->customWidgetsInfo()->isAmbiguousSignal(senderDecl.className,
+                                                                               senderSignature);
+    const bool slotAmbiguous = m_uic->customWidgetsInfo()->isAmbiguousSlot(receiverDecl.className,
+                                                                           slotSignature);
+
     language::SignalSlotOptions signalOptions;
-    if (m_uic->customWidgetsInfo()->isAmbiguousSignal(senderDecl.className, senderSignature))
-        signalOptions.setFlag(language::SignalSlotOption::Ambiguous);
+    signalOptions.setFlag(language::SignalSlotOption::Ambiguous, senderAmbiguous);
+    language::SignalSlotOptions slotOptions;
+    slotOptions.setFlag(language::SignalSlotOption::Ambiguous, slotAmbiguous);
 
     language::SignalSlot theSignal{senderDecl.name, senderSignature,
                                    senderDecl.className, signalOptions};
-    language::SignalSlot theSlot{receiverDecl.name, connection->elementSlot(),
-                                 receiverDecl.className, {}};
+    language::SignalSlot theSlot{receiverDecl.name, slotSignature,
+                                 receiverDecl.className, slotOptions};
 
     m_output << m_indent;
     language::formatConnection(m_output, theSignal, theSlot,
diff --git a/src/tools/uic/customwidgetsinfo.cpp b/src/tools/uic/customwidgetsinfo.cpp
index 169cdad618c..6ec418634c2 100644
--- a/src/tools/uic/customwidgetsinfo.cpp
+++ b/src/tools/uic/customwidgetsinfo.cpp
@@ -78,19 +78,89 @@ bool CustomWidgetsInfo::isCustomWidgetContainer(const QString &className) const
     return false;
 }
 
+// FIXME in 7.0 - QTBUG-124241
+// Remove isAmbiguous logic when widget slots have been disambiguated.
+bool CustomWidgetsInfo::isAmbiguous(const QString &className, const QString &signature,
+                                    QMetaMethod::MethodType type) const
+{
+    using TypeMap = QHash<QString, QMetaMethod::MethodType>;
+    struct AmbiguousInClass {
+        QLatin1StringView className;
+        TypeMap methodMap;
+    };
+
+    static const QList<AmbiguousInClass> ambiguousList = {
+
+        {"QAction"_L1, {{"triggered"_L1, QMetaMethod::Signal}}},
+        {"QCommandLinkButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                                   {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QPushButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                            {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QCheckBox"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                          {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QRadioButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                             {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QToolButton"_L1,  {{"triggered"_L1, QMetaMethod::Signal},
+                            {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QLabel"_L1, {{"setNum"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsView"_L1, {{"invalidateScene"_L1, QMetaMethod::Slot}}},
+        {"QListView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QColumnView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QListWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                           {"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QTableView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QTableWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                            {"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QTreeView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                         {"verticalScrollbarValueChanged"_L1, QMetaMethod::Slot},
+                         {"expandRecursively"_L1, QMetaMethod::Slot}}},
+        {"QTreeWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                           {"verticalScrollbarValueChanged"_L1, QMetaMethod::Slot}
+                           ,{"expandRecursively"_L1, QMetaMethod::Slot}
+                           ,{"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QUndoView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QLCDNumber"_L1, {{"display"_L1, QMetaMethod::Slot}}},
+        {"QMenuBar"_L1, {{"setVisible"_L1, QMetaMethod::Slot}}},
+        {"QTextBrowser"_L1, {{"setSource"_L1, QMetaMethod::Slot}}},
+
+        /*
+        The following widgets with ambiguities are not used in the widget designer:
+
+        {"QSplashScreen"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QCompleter"_L1, {{"activated"_L1, QMetaMethod::Signal},
+                          {"highlighted"_L1, QMetaMethod::Signal}}},
+        {"QSystemTrayIcon"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QStyledItemDelegate"_L1, {{"closeEditor"_L1, QMetaMethod::Signal}}},
+        {"QErrorMessage"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsDropShadowEffect"_L1, {{"setOffset"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsScene"_L1, {{"invalidate"_L1, QMetaMethod::Slot}}},
+        {"QItemDelegate"_L1, {{"closeEditor"_L1, QMetaMethod::Signal}}}
+        */
+    };
+
+    for (auto it = ambiguousList.constBegin(); it != ambiguousList.constEnd(); ++it) {
+        if (extends(className, it->className)) {
+            const qsizetype pos = signature.indexOf(u'(');
+            const QString method = signature.left(pos);
+            const auto methodIterator = it->methodMap.find(method);
+            return methodIterator != it->methodMap.constEnd() && type == methodIterator.value();
+        }
+    }
+    return false;
+}
+
 // Is it ambiguous, resulting in different signals for Python
 // "QAbstractButton::clicked(checked=false)"
 bool CustomWidgetsInfo::isAmbiguousSignal(const QString &className,
                                           const QString &signalSignature) const
 {
-    if (signalSignature.startsWith(u"triggered") && extends(className, "QAction"))
-        return true;
-    if (signalSignature.startsWith(u"clicked(")
-        && extendsOneOf(className, {u"QCommandLinkButton"_s, u"QCheckBox"_s,
-                                    u"QPushButton"_s, u"QRadioButton"_s, u"QToolButton"_s})) {
-        return true;
-    }
-    return false;
+    return isAmbiguous(className, signalSignature, QMetaMethod::Signal);
+}
+
+bool CustomWidgetsInfo::isAmbiguousSlot(const QString &className,
+                                        const QString &signalSignature) const
+{
+    return isAmbiguous(className, signalSignature, QMetaMethod::Slot);
 }
 
 QString CustomWidgetsInfo::realClassName(const QString &className) const
diff --git a/src/tools/uic/customwidgetsinfo.h b/src/tools/uic/customwidgetsinfo.h
index 4bd004bdc72..f336292f2ac 100644
--- a/src/tools/uic/customwidgetsinfo.h
+++ b/src/tools/uic/customwidgetsinfo.h
@@ -7,6 +7,7 @@
 #include "treewalker.h"
 #include <qstringlist.h>
 #include <qmap.h>
+#include <QtCore/qmetaobject.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -38,10 +39,14 @@ public:
 
     bool isAmbiguousSignal(const QString &className,
                            const QString &signalSignature) const;
+    bool isAmbiguousSlot(const QString &className,
+                         const QString &slotSignature) const;
 
 private:
     using NameCustomWidgetMap = QMap<QString, DomCustomWidget*>;
     NameCustomWidgetMap m_customWidgets;
+    bool isAmbiguous(const QString &className, const QString &signature,
+                     QMetaMethod::MethodType type) const;
 };
 
 QT_END_NAMESPACE
diff --git a/src/tools/uic/shared/language.cpp b/src/tools/uic/shared/language.cpp
index bfdce0bc4c3..d59688e3466 100644
--- a/src/tools/uic/shared/language.cpp
+++ b/src/tools/uic/shared/language.cpp
@@ -4,6 +4,7 @@
 #include "language.h"
 
 #include <QtCore/qtextstream.h>
+#include <QtCore/QList>
 
 namespace language {
 
@@ -370,17 +371,40 @@ void _formatStackVariable(QTextStream &str, const char *className, QStringView v
     }
 }
 
-enum OverloadUse {
-    UseOverload,
-    UseOverloadWhenNoArguments, // Use overload only when the argument list is empty,
-                                // in this case there is no chance of connecting
-                                // mismatching T against const T &
-    DontUseOverload
+enum class OverloadUse {
+    Always,
+    WhenAmbiguousOrEmpty, // Use overload if
+                          // - signal/slot is ambiguous
+                          // - argument list is empty (chance of connecting mismatching T against const T &)
+    Never,
 };
 
 // Format a member function for a signal slot connection
-static void formatMemberFnPtr(QTextStream &str, const SignalSlot &s,
-                              OverloadUse useQOverload = DontUseOverload)
+static bool isConstRef(const QStringView &arg)
+{
+    return arg.startsWith(u'Q') && arg != "QPoint"_L1 && arg != "QSize"_L1;
+}
+
+static QString formatOverload(const QStringView &parameters)
+{
+    QString result = "qOverload<"_L1;
+    const auto args = QStringView{parameters}.split(u',');
+    for (qsizetype i = 0, size = args.size(); i < size; ++i) {
+        const auto &arg = args.at(i);
+        if (i > 0)
+            result += u',';
+        const bool constRef = isConstRef(arg);
+        if (constRef)
+            result += "const "_L1;
+        result += arg;
+        if (constRef)
+            result += u'&';
+    }
+    result += u'>';
+    return result;
+}
+
+static void formatMemberFnPtr(QTextStream &str, const SignalSlot &s, OverloadUse useQOverload)
 {
     const qsizetype parenPos = s.signature.indexOf(u'(');
     Q_ASSERT(parenPos >= 0);
@@ -388,11 +412,24 @@ static void formatMemberFnPtr(QTextStream &str, const SignalSlot &s,
 
     const auto parameters = QStringView{s.signature}.mid(parenPos + 1,
                                                s.signature.size() - parenPos - 2);
-    const bool withOverload = useQOverload == UseOverload ||
-            (useQOverload == UseOverloadWhenNoArguments && parameters.isEmpty());
+
+    const bool isAmbiguous = s.options.testFlag(SignalSlotOption::Ambiguous);
+    bool withOverload = false; // just to silence the compiler
+
+    switch (useQOverload) {
+    case OverloadUse::Always:
+        withOverload = true;
+        break;
+    case OverloadUse::Never:
+        withOverload = false;
+        break;
+    case OverloadUse::WhenAmbiguousOrEmpty:
+        withOverload = parameters.empty() || isAmbiguous;
+        break;
+    }
 
     if (withOverload)
-        str << "qOverload<" << parameters << ">(";
+        str << formatOverload(parameters) << '(';
 
     str << '&' << s.className << "::" << functionName;
 
@@ -405,9 +442,9 @@ static void formatMemberFnPtrConnection(QTextStream &str,
                                         const SignalSlot &receiver)
 {
     str << "QObject::connect(" << sender.name << ", ";
-    formatMemberFnPtr(str, sender);
+    formatMemberFnPtr(str, sender, OverloadUse::Never);
     str << ", " << receiver.name << ", ";
-    formatMemberFnPtr(str, receiver, UseOverloadWhenNoArguments);
+    formatMemberFnPtr(str, receiver, OverloadUse::WhenAmbiguousOrEmpty);
     str << ')';
 }
 
diff --git a/tests/auto/tools/uic/baseline/qoverload.ui b/tests/auto/tools/uic/baseline/qoverload.ui
new file mode 100644
index 00000000000..fb9e5294b7d
--- /dev/null
+++ b/tests/auto/tools/uic/baseline/qoverload.ui
@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralWidget">
+   <layout class="QVBoxLayout" name="verticalLayout">
+    <item>
+     <widget class="QSlider" name="horizontalSlider">
+      <property name="orientation">
+       <enum>Qt::Horizontal</enum>
+      </property>
+     </widget>
+    </item>
+    <item>
+     <widget class="QLabel" name="label">
+      <property name="text">
+       <string>TextLabel</string>
+      </property>
+     </widget>
+    </item>
+    <item>
+     <widget class="QLCDNumber" name="lcdNumber"/>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menuBar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>400</width>
+     <height>29</height>
+    </rect>
+   </property>
+  </widget>
+  <widget class="QToolBar" name="mainToolBar">
+   <attribute name="toolBarArea">
+    <enum>TopToolBarArea</enum>
+   </attribute>
+   <attribute name="toolBarBreak">
+    <bool>false</bool>
+   </attribute>
+  </widget>
+  <widget class="QStatusBar" name="statusBar"/>
+ </widget>
+ <layoutdefault spacing="6" margin="11"/>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>horizontalSlider</sender>
+   <signal>valueChanged(int)</signal>
+   <receiver>label</receiver>
+   <slot>setNum(int)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>199</x>
+     <y>67</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>199</x>
+     <y>172</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>label</sender>
+   <signal>linkActivated(QString)</signal>
+   <receiver>lcdNumber</receiver>
+   <slot>display(QString)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>199</x>
+     <y>126</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>199</x>
+     <y>218</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/tests/auto/tools/uic/baseline/qoverload.ui.h b/tests/auto/tools/uic/baseline/qoverload.ui.h
new file mode 100644
index 00000000000..4ab0e37d1f3
--- /dev/null
+++ b/tests/auto/tools/uic/baseline/qoverload.ui.h
@@ -0,0 +1,98 @@
+/********************************************************************************
+** Form generated from reading UI file 'qoverload.ui'
+**
+** Created by: Qt User Interface Compiler version 6.8.0
+**
+** WARNING! All changes made in this file will be lost when recompiling UI file!
+********************************************************************************/
+
+#ifndef QOVERLOAD_H
+#define QOVERLOAD_H
+
+#include <QtCore/QVariant>
+#include <QtWidgets/QApplication>
+#include <QtWidgets/QLCDNumber>
+#include <QtWidgets/QLabel>
+#include <QtWidgets/QMainWindow>
+#include <QtWidgets/QMenuBar>
+#include <QtWidgets/QSlider>
+#include <QtWidgets/QStatusBar>
+#include <QtWidgets/QToolBar>
+#include <QtWidgets/QVBoxLayout>
+#include <QtWidgets/QWidget>
+
+QT_BEGIN_NAMESPACE
+
+class Ui_MainWindow
+{
+public:
+    QWidget *centralWidget;
+    QVBoxLayout *verticalLayout;
+    QSlider *horizontalSlider;
+    QLabel *label;
+    QLCDNumber *lcdNumber;
+    QMenuBar *menuBar;
+    QToolBar *mainToolBar;
+    QStatusBar *statusBar;
+
+    void setupUi(QMainWindow *MainWindow)
+    {
+        if (MainWindow->objectName().isEmpty())
+            MainWindow->setObjectName("MainWindow");
+        MainWindow->resize(400, 300);
+        centralWidget = new QWidget(MainWindow);
+        centralWidget->setObjectName("centralWidget");
+        verticalLayout = new QVBoxLayout(centralWidget);
+        verticalLayout->setSpacing(6);
+        verticalLayout->setContentsMargins(11, 11, 11, 11);
+        verticalLayout->setObjectName("verticalLayout");
+        horizontalSlider = new QSlider(centralWidget);
+        horizontalSlider->setObjectName("horizontalSlider");
+        horizontalSlider->setOrientation(Qt::Horizontal);
+
+        verticalLayout->addWidget(horizontalSlider);
+
+        label = new QLabel(centralWidget);
+        label->setObjectName("label");
+
+        verticalLayout->addWidget(label);
+
+        lcdNumber = new QLCDNumber(centralWidget);
+        lcdNumber->setObjectName("lcdNumber");
+
+        verticalLayout->addWidget(lcdNumber);
+
+        MainWindow->setCentralWidget(centralWidget);
+        menuBar = new QMenuBar(MainWindow);
+        menuBar->setObjectName("menuBar");
+        menuBar->setGeometry(QRect(0, 0, 400, 29));
+        MainWindow->setMenuBar(menuBar);
+        mainToolBar = new QToolBar(MainWindow);
+        mainToolBar->setObjectName("mainToolBar");
+        MainWindow->addToolBar(Qt::ToolBarArea::TopToolBarArea, mainToolBar);
+        statusBar = new QStatusBar(MainWindow);
+        statusBar->setObjectName("statusBar");
+        MainWindow->setStatusBar(statusBar);
+
+        retranslateUi(MainWindow);
+        QObject::connect(horizontalSlider, &QSlider::valueChanged, label, qOverload<int>(&QLabel::setNum));
+        QObject::connect(label, &QLabel::linkActivated, lcdNumber, qOverload<const QString&>(&QLCDNumber::display));
+
+        QMetaObject::connectSlotsByName(MainWindow);
+    } // setupUi
+
+    void retranslateUi(QMainWindow *MainWindow)
+    {
+        MainWindow->setWindowTitle(QCoreApplication::translate("MainWindow", "MainWindow", nullptr));
+        label->setText(QCoreApplication::translate("MainWindow", "TextLabel", nullptr));
+    } // retranslateUi
+
+};
+
+namespace Ui {
+    class MainWindow: public Ui_MainWindow {};
+} // namespace Ui
+
+QT_END_NAMESPACE
+
+#endif // QOVERLOAD_H