Fix WhenChecker after enum property type change

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

@@ -17,9 +17,11 @@
 package org.jetbrains.jet.lang.cfg;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.descriptors.ClassKind;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.descriptors.VariableDescriptor;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.BindingTrace;
@@ -65,15 +67,22 @@ public class WhenChecker {
         return isExhaust && notEmpty;
     }
 
-    private static boolean containsEnumEntryCase(@NotNull JetWhenExpression whenExpression, @NotNull ClassDescriptor enumEntry, @NotNull BindingTrace trace) {
+    private static boolean containsEnumEntryCase(
+            @NotNull JetWhenExpression whenExpression,
+            @NotNull ClassDescriptor enumEntry,
+            @NotNull BindingTrace trace
+    ) {
         assert enumEntry.getKind() == ClassKind.ENUM_ENTRY;
         for (JetWhenEntry whenEntry : whenExpression.getEntries()) {
             for (JetWhenCondition condition : whenEntry.getConditions()) {
                 if (condition instanceof JetWhenConditionWithExpression) {
                     JetExpression patternExpression = ((JetWhenConditionWithExpression) condition).getExpression();
-                    JetType type = trace.get(BindingContext.EXPRESSION_TYPE, patternExpression);
+                    JetSimpleNameExpression reference = getReference(patternExpression);
-                    if (type == null) continue;
+                    if (reference == null) continue;
-                    if (type.getConstructor().getDeclarationDescriptor() == enumEntry) {
+                    DeclarationDescriptor target = trace.get(BindingContext.REFERENCE_TARGET, reference);
+                    if (target == null) continue;
+                    ClassDescriptor classDescriptor = trace.get(BindingContext.OBJECT_DECLARATION_CLASS, (VariableDescriptor) target);
+                    if (classDescriptor == enumEntry) {
                         return true;
                     }
                 }
@@ -81,4 +90,18 @@ public class WhenChecker {
         }
         return false;
     }
+
+    @Nullable
+    private static JetSimpleNameExpression getReference(@Nullable JetExpression expression) {
+        if (expression == null) {
+            return null;
+        }
+        if (expression instanceof JetSimpleNameExpression) {
+            return (JetSimpleNameExpression) expression;
+        }
+        if (expression instanceof JetQualifiedExpression) {
+            return getReference(((JetQualifiedExpression) expression).getSelectorExpression());
+        }
+        return null;
+    }
 }