fix for KT-247

idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -74,7 +74,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
             "DOUBLE_TYPE_INFO"
     };
 
-    private final InstructionAdapter v;
+    private final InstructionAdapterEx v;
     private final FrameMap myMap;
     private final JetTypeMapper typeMapper;
     private final GenerationState state;
@@ -93,7 +93,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         this.typeMapper = state.getTypeMapper();
         this.returnType = returnType;
         this.state = state;
-        this.v = new InstructionAdapter(v);
+        this.v = new InstructionAdapterEx(v);
         this.bindingContext = state.getBindingContext();
         this.context = context;
         this.intrinsics = state.getIntrinsics();
@@ -1039,16 +1039,24 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         Label end = new Label();
         v.dup();
         v.ifnull(ifnull);
-        gen(expression.getSelectorExpression());
+        JetType receiverType = bindingContext.get(BindingContext.EXPRESSION_TYPE, expression.getReceiverExpression());
+        StackValue propValue = genQualified(StackValue.onStack(typeMapper.mapType(receiverType)), expression.getSelectorExpression());
+        Type type = propValue.type;
+        propValue.put(type, v);
+        if(JetTypeMapper.isPrimitive(type) && !type.equals(Type.VOID_TYPE)) {
+            v.valueOf(type);
+            type = typeMapper.boxType(type);
+        }
         v.goTo(end);
+
         v.mark(ifnull);
-        // null is already on stack here after the dup
-        JetType expressionType = bindingContext.get(BindingContext.EXPRESSION_TYPE, expression);
-        if (expressionType.equals(JetStandardClasses.getUnitType())) {
-            v.pop();
+        v.pop();
+        if(!propValue.type.equals(Type.VOID_TYPE)) {
+            v.aconst(null);
         }
         v.mark(end);
-        return StackValue.onStack(typeMapper.mapType(expressionType));
+
+        return StackValue.onStack(type);
     }
 
     @Override
@@ -1138,10 +1146,20 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
     }
 
     private StackValue generateEquals(JetExpression left, JetExpression right, IElementType opToken) {
-        final Type leftType = expressionType(left);
-        final Type rightType = expressionType(right);
-        gen(left, leftType);
-        gen(right, rightType);
+        Type leftType = expressionType(left);
+        Type rightType = expressionType(right);
+        if(JetTypeMapper.isPrimitive(leftType) != JetTypeMapper.isPrimitive(rightType)) {
+            gen(left, leftType);
+            v.valueOf(leftType);
+            leftType = typeMapper.boxType(leftType);
+            gen(right, rightType);
+            v.valueOf(rightType);
+            rightType = typeMapper.boxType(rightType);
+        }
+        else {
+            gen(left, leftType);
+            gen(right, rightType);
+        }
         return generateEqualsForExpressionsOnStack(opToken, leftType, rightType);
     }
 

idea/src/org/jetbrains/jet/codegen/InstructionAdapterEx.java

@@ -1,6 +1,7 @@
 package org.jetbrains.jet.codegen;
 
 import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.commons.InstructionAdapter;
 import org.objectweb.asm.commons.Method;

idea/testData/codegen/regressions/kt247.jet

@@ -0,0 +1,38 @@
+fun t1() : Boolean {
+    val s1 : String? = "sff"
+    val s2 : String? = null
+    return s1?.length == 3 && s2?.length == null
+}
+
+fun t2() : Boolean {
+    val c1: C? = C(1)
+    val c2: C? = null
+    return c1?.x == 1 && c2?.x == null
+}
+
+fun t3() {
+    val d: D = D("s")
+    System.out?.println(d?.s)
+    System.out?.println(d?.s == "s") //prints true
+    System.out?.println(d)    //ok
+}
+
+fun t4() {
+    val e: E? = E()
+    System.out?.println(e?.foo() == e) //verify error
+    System.out?.println(e?.foo())  //verify error
+}
+
+fun box() : String {
+    if(!t1 ()) return "fail"
+    if(!t2 ()) return "fail"
+    t3()
+    t4()
+    return "OK"
+}
+
+class C(val x: Int)
+class D(val s: String)
+class E() {
+    fun foo() = 1
+}

idea/tests/org/jetbrains/jet/codegen/Kt247Test.java

@@ -0,0 +1,7 @@
+package org.jetbrains.jet.codegen;
+
+public class Kt247Test extends CodegenTestCase {
+    public void testMe () throws Exception {
+        blackBoxFile("regressions/kt247.jet");
+    }
+}