Fix char conversions in QML

This is a partial revert of 90b06e2773842, as it had unwanted side
effects. The original intention was to make assignment from char to
string possible, or more specifically, we wanted a solution where a
QChar could be assigned to a QString, as a character and not a string
representation of its value. While this behavior is desirable for
QChar, we most likely want the opposite for the regular character types.

Task-number: QTBUG-49232
Change-Id: I82d5f72b900fe984c4db1478fd52a9eb69ad2ee6
Reviewed-by: Michael Brasser <michael.brasser@live.com>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 43 insertions, 66 deletions

diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 5dc3e6151f..557b678ef8 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -1143,8 +1143,13 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
         return value.integerValue();
     if (value.isNumber())
         return value.asDouble();
-    if (value.isString())
-        return value.stringValue()->toQString();
+    if (value.isString()) {
+        const QString &str = value.toQString();
+        // QChars are stored as a strings
+        if (typeHint == QVariant::Char && str.size() == 1)
+            return str.at(0);
+        return str;
+    }
     if (const QV4::QQmlLocaleData *ld = value.as<QV4::QQmlLocaleData>())
         return ld->d()->locale;
     if (const QV4::DateObject *d = value.as<DateObject>())
@@ -1284,9 +1289,9 @@ QV4::ReturnedValue QV4::ExecutionEngine::fromVariant(const QVariant &variant)
             case QMetaType::UShort:
                 return QV4::Encode((int)*reinterpret_cast<const unsigned short*>(ptr));
             case QMetaType::Char:
-                return newString(QChar::fromLatin1(*reinterpret_cast<const char *>(ptr)))->asReturnedValue();
+                return QV4::Encode((int)*reinterpret_cast<const char*>(ptr));
             case QMetaType::UChar:
-                return newString(QChar::fromLatin1(*reinterpret_cast<const unsigned char *>(ptr)))->asReturnedValue();
+                return QV4::Encode((int)*reinterpret_cast<const unsigned char*>(ptr));
             case QMetaType::QChar:
                 return newString(*reinterpret_cast<const QChar *>(ptr))->asReturnedValue();
             case QMetaType::QDateTime:
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index 1b78ada698..1eaff6b600 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -1327,29 +1327,8 @@ bool QQmlPropertyPrivate::write(QObject *object,
 
         bool ok = false;
         QVariant v;
-        if (variantType == QVariant::String) {
-            const QString &str = value.toString();
-            const bool targetIsChar = (propertyType == qMetaTypeId<QChar>()
-                                       || propertyType == qMetaTypeId<char>()
-                                       || propertyType == qMetaTypeId<unsigned char>());
-            // If the string contains only one character and the target is a char, try converting it.
-            if (targetIsChar) {
-                if (str.size() != 1)
-                    return false; // We can only convert if the string contains exactly one character.
-
-                const QChar &qChar = str.at(0);
-                if (propertyType == qMetaTypeId<QChar>()) {
-                    v = qChar;
-                    ok = true;
-                } else if (propertyType == qMetaTypeId<char>() || propertyType == qMetaTypeId<unsigned char>()) {
-                    const char c = qChar.toLatin1();
-                    v = c;
-                    ok = (qChar == c);
-                }
-            } else {
-                v = QQmlStringConverters::variantFromString(str, propertyType, &ok);
-            }
-        }
+        if (variantType == QVariant::String)
+            v = QQmlStringConverters::variantFromString(value.toString(), propertyType, &ok);
 
         if (!ok) {
             v = value;
diff --git a/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp b/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
index d338e6f5ad..739af3782e 100644
--- a/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
+++ b/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
@@ -66,6 +66,7 @@ private slots:
     void qtbug_22535();
     void evalAfterInvalidate();
     void qobjectDerived();
+    void qtbug_49232();
 
 private:
     QQmlEngine engine;
@@ -205,6 +206,8 @@ class TestObject : public QObject
     Q_PROPERTY(int a READ a NOTIFY aChanged)
     Q_PROPERTY(int b READ b NOTIFY bChanged)
     Q_PROPERTY(int c READ c NOTIFY cChanged)
+    Q_PROPERTY(char d READ d NOTIFY dChanged)
+    Q_PROPERTY(uchar e READ e NOTIFY eChanged)
 
 public:
     TestObject() : _a(10), _b(10), _c(10) {}
@@ -218,15 +221,25 @@ public:
     int c() const { return _c; }
     void setC(int c) { _c = c; emit cChanged(); }
 
+    char d() const { return _d; }
+    void setD(char d) { _d = d; emit dChanged(); }
+
+    uchar e() const { return _e; }
+    void setE(uchar e) { _e = e; emit eChanged(); }
+
 signals:
     void aChanged();
     void bChanged();
     void cChanged();
+    void dChanged();
+    void eChanged();
 
 private:
     int _a;
     int _b;
     int _c;
+    char _d;
+    uchar _e;
 };
 
 #define TEST_CONTEXT_PROPERTY(ctxt, name, value) \
@@ -699,6 +712,22 @@ void tst_qqmlcontext::qobjectDerived()
     QCOMPARE(command.count, 2);
 }
 
+void tst_qqmlcontext::qtbug_49232()
+{
+    TestObject testObject;
+    testObject.setD('a');
+    testObject.setE(97);
+
+    QQmlEngine engine;
+    engine.rootContext()->setContextProperty("TestObject", &testObject);
+    QQmlComponent component(&engine);
+    component.setData("import QtQuick 2.0; QtObject { property int valueOne: TestObject.d; property int valueTwo: TestObject.e }", QUrl());
+    QScopedPointer<QObject> obj(component.create());
+
+    QCOMPARE(obj->property("valueOne"), QVariant('a'));
+    QCOMPARE(obj->property("valueTwo"), QVariant(97));
+}
+
 QTEST_MAIN(tst_qqmlcontext)
 
 #include "tst_qqmlcontext.moc"
diff --git a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
index 6ada14ce79..86c13065fa 100644
--- a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
+++ b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
@@ -329,11 +329,8 @@ class PropertyObject : public QObject
     Q_PROPERTY(MyQmlObject *qmlObject READ qmlObject)
     Q_PROPERTY(MyQObject *qObject READ qObject WRITE setQObject NOTIFY qObjectChanged)
     Q_PROPERTY(QString stringProperty READ stringProperty WRITE setStringProperty)
-    Q_PROPERTY(char charProperty READ charProperty WRITE setCharProperty)
     Q_PROPERTY(QChar qcharProperty READ qcharProperty WRITE setQcharProperty)
     Q_PROPERTY(QChar constQChar READ constQChar STORED false CONSTANT FINAL)
-    Q_PROPERTY(char constChar READ constChar STORED false CONSTANT FINAL)
-    Q_PROPERTY(int constInt READ constInt STORED false CONSTANT FINAL)
 
     Q_CLASSINFO("DefaultProperty", "defaultProperty")
 public:
@@ -370,15 +367,11 @@ public:
     }
 
     QString stringProperty() const { return m_stringProperty;}
-    char charProperty() const { return m_charProperty; }
     QChar qcharProperty() const { return m_qcharProperty; }
 
     QChar constQChar() const { return 0x25cf; /* Unicode: black circle */ }
-    char constChar() const { return 'A'; }
-    int constInt() const { return 123456; }
 
     void setStringProperty(QString arg) { m_stringProperty = arg; }
-    void setCharProperty(char arg) { m_charProperty = arg; }
     void setQcharProperty(QChar arg) { m_qcharProperty = arg; }
 
 signals:
@@ -395,7 +388,6 @@ private:
     MyQmlObject m_qmlObject;
     MyQObject *m_qObject;
     QString m_stringProperty;
-    char m_charProperty;
     QChar m_qcharProperty;
 };
 
@@ -1408,23 +1400,14 @@ void tst_qqmlproperty::write()
     // Char/string-property
     {
         PropertyObject o;
-        QQmlProperty charProperty(&o, "charProperty");
         QQmlProperty qcharProperty(&o, "qcharProperty");
         QQmlProperty stringProperty(&o, "stringProperty");
 
         const int black_circle = 0x25cf;
 
-        QCOMPARE(charProperty.write(QString("foo")), false);
-        QCOMPARE(charProperty.write('Q'), true);
-        QCOMPARE(charProperty.read(), QVariant('Q'));
-        QCOMPARE(charProperty.write(QString("t")), true);
-        QCOMPARE(charProperty.read(), QVariant('t'));
-
         QCOMPARE(qcharProperty.write(QString("foo")), false);
         QCOMPARE(qcharProperty.write('Q'), true);
         QCOMPARE(qcharProperty.read(), QVariant('Q'));
-        QCOMPARE(qcharProperty.write(QString("t")), true);
-        QCOMPARE(qcharProperty.read(), QVariant('t'));
         QCOMPARE(qcharProperty.write(QChar(black_circle)), true);
         QCOMPARE(qcharProperty.read(), QVariant(QChar(black_circle)));
 
@@ -1433,19 +1416,10 @@ void tst_qqmlproperty::write()
         QCOMPARE(o.stringProperty(), QString("bar"));
         QCOMPARE(stringProperty.write(QVariant(1234)), true);
         QCOMPARE(stringProperty.read().toString(), QString::number(1234));
+        QCOMPARE(stringProperty.write('A'), true);
+        QCOMPARE(stringProperty.read().toString(), QString::number('A'));
         QCOMPARE(stringProperty.write(QChar(black_circle)), true);
-        QCOMPARE(stringProperty.read(), QVariant(QString(QChar(black_circle))));
-
-        { // char -> QString
-            QQmlComponent component(&engine);
-            component.setData("import Test 1.0\nPropertyObject { stringProperty: constChar }", QUrl());
-            PropertyObject *obj = qobject_cast<PropertyObject*>(component.create());
-            QVERIFY(obj != 0);
-            if (obj) {
-                QQmlProperty stringProperty(obj, "stringProperty");
-                QCOMPARE(stringProperty.read(), QVariant(QString(obj->constChar())));
-            }
-        }
+        QCOMPARE(stringProperty.read(), QVariant(QChar(black_circle)));
 
         { // QChar -> QString
             QQmlComponent component(&engine);
@@ -1458,16 +1432,6 @@ void tst_qqmlproperty::write()
             }
         }
 
-        { // int -> QString
-            QQmlComponent component(&engine);
-            component.setData("import Test 1.0\nPropertyObject { stringProperty: constInt }", QUrl());
-            PropertyObject *obj = qobject_cast<PropertyObject*>(component.create());
-            QVERIFY(obj != 0);
-            if (obj) {
-                QQmlProperty stringProperty(obj, "stringProperty");
-                QCOMPARE(stringProperty.read(), QVariant(QString::number(obj->constInt())));
-            }
-        }
     }
 
     // VariantMap-property