Convert null variant values to empty lists

... if their declared type is a list. This is a workaround for
QTBUG-51237.

Change-Id: Ie9e02f5fd125ce73b993e59af0e3dc2b47fe14c1
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

6 files changed, 63 insertions, 3 deletions

diff --git a/src/lib/corelib/language/evaluatorscriptclass.cpp b/src/lib/corelib/language/evaluatorscriptclass.cpp
index 8230d3990..aa07935dc 100644
--- a/src/lib/corelib/language/evaluatorscriptclass.cpp
+++ b/src/lib/corelib/language/evaluatorscriptclass.cpp
@@ -398,8 +398,14 @@ static QString overriddenSourceDirectory(const Item *item)
 }
 
 inline void convertToPropertyType(const Item *item, const PropertyDeclaration::Type t,
-        QScriptValue &v)
+        Value::Type valueType, QScriptValue &v)
 {
+    if (valueType == Value::VariantValueType && v.isUndefined()
+            && (t == PropertyDeclaration::StringList || t == PropertyDeclaration::PathList)) {
+        v = v.engine()->newArray(); // QTBUG-51237
+        return;
+    }
+
     if (v.isUndefined() || v.isError())
         return;
     switch (t) {
@@ -497,7 +503,7 @@ QScriptValue EvaluatorScriptClass::property(const QScriptValue &object, const QS
         converter.start();
 
         const PropertyDeclaration decl = data->item->propertyDeclaration(name.toString());
-        convertToPropertyType(data->item, decl.type(), result);
+        convertToPropertyType(data->item, decl.type(), value->type(), result);
     }
 
     if (debugProperties)
diff --git a/src/lib/corelib/language/projectresolver.cpp b/src/lib/corelib/language/projectresolver.cpp
index e712aff49..bfb2eb74c 100644
--- a/src/lib/corelib/language/projectresolver.cpp
+++ b/src/lib/corelib/language/projectresolver.cpp
@@ -1129,7 +1129,12 @@ QVariantMap ProjectResolver::evaluateProperties(Item *item, Item *propertiesCont
             if (result.contains(it.key()))
                 break;
             VariantValuePtr vvp = it.value().staticCast<VariantValue>();
-            result[it.key()] = vvp->value();
+            QVariant v = vvp->value();
+
+            if (v.isNull() && !item->propertyDeclaration(it.key()).isScalar()) // QTBUG-51237
+                v = QStringList();
+
+            result[it.key()] = v;
             break;
         }
         }
diff --git a/tests/auto/blackbox/testdata/QTBUG-51237/modules/mymodule/mymodule.qbs b/tests/auto/blackbox/testdata/QTBUG-51237/modules/mymodule/mymodule.qbs
new file mode 100644
index 000000000..223da0b3c
--- /dev/null
+++ b/tests/auto/blackbox/testdata/QTBUG-51237/modules/mymodule/mymodule.qbs
@@ -0,0 +1,6 @@
+import qbs
+
+Module {
+    property stringList theProperty: []
+    //property stringList otherProperty: theProperty.concat([])
+}
diff --git a/tests/auto/blackbox/testdata/QTBUG-51237/qtbug-51237.qbs b/tests/auto/blackbox/testdata/QTBUG-51237/qtbug-51237.qbs
new file mode 100644
index 000000000..e1f8d8ef6
--- /dev/null
+++ b/tests/auto/blackbox/testdata/QTBUG-51237/qtbug-51237.qbs
@@ -0,0 +1,22 @@
+import qbs
+
+Product {
+    type: "custom"
+    Depends { name: "mymodule" }
+    Rule {
+        multiplex: true
+        Artifact {
+            filePath: "dummy.custom"
+            fileTags: ["custom"]
+        }
+        prepare: {
+            var theProperty = product.moduleProperty("mymodule", "theProperty");
+            if (!theProperty)
+                throw "Oh no!";
+            var dummy = new JavaScriptCommand();
+            dummy.silent = true;
+            dummy.sourceCode = function() {};
+            return [dummy];
+        }
+    }
+}
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 80c3a1f1c..74329abf2 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -2335,6 +2335,26 @@ void TestBlackbox::qobjectInObjectiveCpp()
     QCOMPARE(runQbs(), 0);
 }
 
+void TestBlackbox::qtBug51237()
+{
+    const QString profileName = "profile-qtBug51237";
+    const QString propertyName = "mymodule.theProperty";
+    {
+        Settings settings((QString()));
+        Profile profile(profileName, &settings);
+        profile.setValue(propertyName, QStringList());
+    }
+    Settings settings((QString()));
+    qbs::Internal::TemporaryProfile profile(profileName, &settings);
+    const QVariant propertyValue = profile.p.value(propertyName);
+    QVERIFY(!propertyValue.isValid()); // QTBUG-51237
+    QDir::setCurrent(testDataDir + "/QTBUG-51237");
+    QbsRunParameters params;
+    params.arguments << "profile:" + profileName;
+    params.useProfile = false;
+    QCOMPARE(runQbs(params), 0);
+}
+
 void TestBlackbox::dynamicMultiplexRule()
 {
     const QString testDir = testDataDir + "/dynamicMultiplexRule";
diff --git a/tests/auto/blackbox/tst_blackbox.h b/tests/auto/blackbox/tst_blackbox.h
index 64e3b0770..b5a539bb8 100644
--- a/tests/auto/blackbox/tst_blackbox.h
+++ b/tests/auto/blackbox/tst_blackbox.h
@@ -199,6 +199,7 @@ private slots:
     void qbsVersion();
     void qmlDebugging();
     void qobjectInObjectiveCpp();
+    void qtBug51237();
     void radAfterIncompleteBuild_data();
     void radAfterIncompleteBuild();
     void recursiveRenaming();