# KT-1571 Fixed. Frontend fails to check val reassigment for operator overloading.

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetFlowInformationProvider.java

@@ -313,8 +313,6 @@ public class JetFlowInformationProvider {
             hasBackingField = trace.get(BindingContext.BACKING_FIELD_REQUIRED, (PropertyDescriptor) variableDescriptor);
         }
         if ((isInitializedNotHere || !hasBackingField) && !variableDescriptor.isVar() && !varWithValReassignErrorGenerated.contains(variableDescriptor)) {
-            varWithValReassignErrorGenerated.add(variableDescriptor);
-
             boolean hasReassignMethodReturningUnit = false;
             JetSimpleNameExpression operationReference = null;
             PsiElement parent = expression.getParent();
@@ -343,6 +341,7 @@ public class JetFlowInformationProvider {
                 }
             }
             if (!hasReassignMethodReturningUnit) {
+                varWithValReassignErrorGenerated.add(variableDescriptor);
                 trace.report(Errors.VAL_REASSIGNMENT.on(expression, variableDescriptor));
                 return true;
             }

compiler/testData/diagnostics/tests/controlFlowAnalysis/kt1571.jet

@@ -0,0 +1,42 @@
+//KT-1571 Frontend fails to check val reassigment for operator overloading.
+package kt1571
+
+var c0 = 0
+var c1 = 0
+var c2 = 0
+
+class A() {
+    var p = 0
+    fun divAssign(<!UNUSED_PARAMETER!>a<!> : Int) {
+        c1++;
+    }
+    fun times(<!UNUSED_PARAMETER!>a<!> : Int) : A {
+        c2++;
+        return this;
+    }
+}
+
+val a : A = A()
+get() {
+    c0++
+    return $a
+}
+
+fun box() : String {
+
+    a /= 3
+    if (c0 != 1) {
+        return "1"
+    }
+    if (c1 != 1) {
+        return "2"
+    }
+    <!VAL_REASSIGNMENT!>a<!> *= 3 // a = a * 3, shouldn't be able to do this on val
+    if (c0 != 2) {
+        return "3"
+    }
+    if (c2 != 1) {
+        return "4"
+    }
+    return "OK"
+}