Fix AND expression in v4

The type of the and expressions, e.g. (a && b), were being assigned
to the type of the right hand expression (b). As reported in
QTBUG-24660, this approach could lead to some unexpected behaviors.

Now, when the left and right hand expressions are of different types,
the responsability to deal with the and expression is delegated to v8.

Task-number: QTBUG-24660
Change-Id: Ic42ebb035e62e2f197c337b2106d00453a99f04c
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/qml/qml/v4/qv4irbuilder.cpp

@@ -911,12 +911,15 @@ bool QV4IRBuilder::visit(AST::BinaryExpression *ast)
             IR::BasicBlock *iffalse = _function->newBasicBlock();
             IR::BasicBlock *endif = _function->newBasicBlock();
 
-            condition(ast->left, iftrue, iffalse);
+            ExprResult left = expression(ast->left);
+            IR::Temp *cond = _block->TEMP(IR::BoolType);
+            _block->MOVE(cond, left);
+            _block->CJUMP(cond, iftrue, iffalse);
 
             IR::Temp *r = _block->TEMP(IR::InvalidType);
 
             _block = iffalse;
-            _block->MOVE(r, _block->CONST(IR::BoolType, 0)); // ### use the right null value
+            _block->MOVE(r, cond);
             _block->JUMP(endif);
 
             _block = iftrue;
@@ -924,9 +927,12 @@ bool QV4IRBuilder::visit(AST::BinaryExpression *ast)
             _block->MOVE(r, right);
             _block->JUMP(endif);
 
+            if (left.type() != right.type())
+                discard();
+
             _block = endif;
 
-            r->type = right.type(); // ### not exactly, it can be IR::BoolType.
+            r->type = right.type();
             _expr.code = r;
         }
     } break;

tests/auto/qml/v4/data/logicalAnd.2.qml

@@ -0,0 +1,6 @@
+import Qt.v4 1.0
+
+Result {
+    property string s: "foo" && "bar"
+    result: s == "bar"
+}

tests/auto/qml/v4/data/logicalAnd.3.qml

@@ -0,0 +1,8 @@
+import Qt.v4 1.0
+
+Result {
+    property string s: ""
+    property bool flag: true
+
+    result: (s && flag) == ""
+}

tests/auto/qml/v4/data/logicalAnd.4.qml

@@ -0,0 +1,8 @@
+import Qt.v4 1.0
+
+Result {
+    property string s: "foo"
+    property bool flag: true
+
+    result: (!flag && s) == false
+}

tests/auto/qml/v4/data/logicalAnd.5.qml

@@ -0,0 +1,7 @@
+import Qt.v4 1.0
+
+Result {
+    property bool flag: true
+
+    result: (null && flag) == null
+}

tests/auto/qml/v4/data/logicalAnd.6.qml

@@ -0,0 +1,9 @@
+import Qt.v4 1.0
+
+Result {
+    property string s: ""
+    property bool flag: true
+    property string subresult: s && flag
+
+    result: subresult === ""
+}

tests/auto/qml/v4/data/logicalAnd.7.qml

@@ -0,0 +1,9 @@
+import Qt.v4 1.0
+
+Result {
+    property real nan: Number.NaN
+    property bool flag: true
+    property real subresult: nan && flag
+
+    result: isNaN(subresult)
+}

tests/auto/qml/v4/data/logicalAnd.qml

@@ -0,0 +1,6 @@
+import Qt.v4 1.0
+
+Result {
+    property int a: 10
+    result: a == 10 && a == 2
+}

tests/auto/qml/v4/data/nestedLogicalAnd.qml

@@ -0,0 +1,14 @@
+import Qt.v4 1.0
+
+Result {
+    property bool val1: false
+    property bool val2: true
+    property bool val3: false
+
+    property bool b1: (true && true && false)
+    property bool b2: (true && (false && true))
+    property bool b3: ((true && true) && true)
+    property bool b4: (val1 && (val2 && val3)) ? true : false
+
+    result: !b1 && !b2 && b3 && !b4
+}

tests/auto/qml/v4/tst_v4.cpp

@@ -64,6 +64,8 @@ private slots:
     void unnecessaryReeval();
     void logicalOr();
     void nestedLogicalOr();
+    void logicalAnd();
+    void nestedLogicalAnd();
     void conditionalExpr();
     void qtscript();
     void qtscript_data();
@@ -208,6 +210,115 @@ void tst_v4::nestedLogicalOr()
     delete o;
 }
 
+void tst_v4::logicalAnd()
+{
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 0);
+        delete o;
+    }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.2.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.3.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+
+    {
+        // QTBUG-24660
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.4.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.5.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.6.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("logicalAnd.7.qml"));
+
+        QObject *o = component.create();
+        QVERIFY(o != 0);
+
+        ResultObject *ro = qobject_cast<ResultObject *>(o);
+        QVERIFY(ro != 0);
+
+        QCOMPARE(ro->result(), 1);
+        delete o;
+    }
+}
+
+void tst_v4::nestedLogicalAnd()
+{
+    QQmlComponent component(&engine, testFileUrl("nestedLogicalAnd.qml"));
+
+    QObject *o = component.create();
+    QVERIFY(o != 0);
+
+    ResultObject *ro = qobject_cast<ResultObject *>(o);
+    QVERIFY(ro != 0);
+
+    QCOMPARE(ro->result(), 1);
+    delete o;
+}
+
 void tst_v4::conditionalExpr()
 {
     {