1 files changed, 30 insertions, 5 deletions
diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 0aaa471e23..f6b97262c3 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -19,7 +19,9 @@
 #include <private/qv4mm_p.h>
 #include <private/qv4jscall_p.h>
 #include <private/qv4qobjectwrapper_p.h>
+#include <private/qv4qmetaobjectwrapper_p.h>
 #include <private/qv4urlobject_p.h>
+#include <private/qqmlbuiltins_p.h>
 
 /*!
   \since 5.0
@@ -163,10 +165,11 @@
 /*!
     \enum QJSValue::ObjectConversionBehavior
 
-    This enum is used to specify how JavaScript objects without an equivalent
+    This enum is used to specify how JavaScript objects and symbols without an equivalent
     native Qt type should be treated when converting to QVariant.
 
     \value ConvertJSObjects A best-effort, possibly lossy, conversion is attempted.
+           Symbols are converted to QString.
 
     \value RetainJSObjects The value is retained as QJSValue wrapped in QVariant.
 */
@@ -371,8 +374,11 @@ bool QJSValue::isError() const
 }
 
 /*!
-  Returns true if this QJSValue is an object of the URL class;
+  Returns true if this QJSValue is an object of the URL JavaScript class;
   otherwise returns false.
+
+  \note For a QJSValue that contains a QUrl, this function returns false.
+  However, \c{toVariant().value<QUrl>()} works in both cases.
 */
 bool QJSValue::isUrl() const
 {
@@ -446,16 +452,32 @@ bool QJSValue::isCallable() const
     return QJSValuePrivate::asManagedType<FunctionObject>(this);
 }
 
+#if QT_DEPRECATED_SINCE(6, 9)
 /*!
+  \deprecated [6.9]
   Returns true if this QJSValue is a variant value;
   otherwise returns false.
 
+  \warning This function is likely to give unexpected results.
+  A variant value is only constructed by the QJSEngine in a very
+  limited number of cases. This used to be different before Qt
+  5.14, where \l{QJSEngine::toScriptValue} would have created
+  them for more types instead of corresponding ECMAScript types.
+  You can get a valid \l QVariant via \l toVariant for many values
+  for which \c{isVariant} returns false.
+
   \sa toVariant()
 */
 bool QJSValue::isVariant() const
 {
-    return QJSValuePrivate::asManagedType<QV4::VariantObject>(this);
+    if (QJSValuePrivate::asManagedType<QV4::VariantObject>(this))
+        return true;
+    if (auto vt = QJSValuePrivate::asManagedType<QV4::QQmlValueTypeWrapper>(this))
+        if (vt->metaObject() == &QQmlVarForeign::staticMetaObject)
+            return true;
+    return false;
 }
+#endif
 
 /*!
   Returns the string value of this QJSValue, as defined in
@@ -634,8 +656,11 @@ QVariant QJSValue::toVariant(QJSValue::ObjectConversionBehavior behavior) const
     if (val.isString())
         return QVariant(val.toQString());
     if (val.as<QV4::Managed>()) {
-        return QV4::ExecutionEngine::toVariant(
-                    val, /*typeHint*/ QMetaType{}, behavior == RetainJSObjects);
+        if (behavior == RetainJSObjects)
+            return QV4::ExecutionEngine::toVariant(
+                    val, /*typeHint*/ QMetaType{}, /*createJSValueForObjectsAndSymbols=*/ true);
+        else
+            return QV4::ExecutionEngine::toVariantLossy(val);
     }
 
     Q_ASSERT(false);