From 00da5fe1fbdf2eb94b391f4a1e6f9c17d92d1b84 Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Tue, 10 Dec 2013 21:07:05 +0400
Subject: [PATCH] Fix VerifyError for 'when' of type 'Unit?'

---
 .../src/org/jetbrains/jet/codegen/StackValue.java    | 10 +++++-----
 .../testData/codegen/box/unit/nullableUnitInWhen1.kt | 12 ++++++++++++
 .../testData/codegen/box/unit/nullableUnitInWhen2.kt | 12 ++++++++++++
 .../generated/BlackBoxCodegenTestGenerated.java      | 10 ++++++++++
 4 files changed, 39 insertions(+), 5 deletions(-)
 create mode 100644 compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt
 create mode 100644 compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt

diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java b/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
index c69abf2286f..4a4cb7af35f 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
@@ -234,8 +234,10 @@ public abstract class StackValue {
             }
         }
         else if (toType.equals(JET_UNIT_TYPE)) {
-            pop(v, fromType);
-            putUnitInstance(v);
+            if (!fromType.equals(getType(Void.class))) {
+                pop(v, fromType);
+                putUnitInstance(v);
+            }
         }
         else if (toType.getSort() == Type.ARRAY) {
             v.checkcast(toType);
@@ -431,9 +433,7 @@ public abstract class StackValue {
                 v.aconst(value);
             }
 
-            if (value != null) {
-                coerceTo(type, v);
-            }
+            coerceTo(type, v);
         }
 
         @Override
diff --git a/compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt b/compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt
new file mode 100644
index 00000000000..2d6768af748
--- /dev/null
+++ b/compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt
@@ -0,0 +1,12 @@
+fun foo() {}
+
+fun box(): String {
+    when ("A") {
+        "B" -> foo()
+        else -> null
+    }
+
+    foo()
+
+    return "OK"
+}
diff --git a/compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt b/compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt
new file mode 100644
index 00000000000..47807e50f19
--- /dev/null
+++ b/compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt
@@ -0,0 +1,12 @@
+fun foo() {}
+
+fun box(): String {
+    when ("A") {
+        "B" -> null
+        else -> foo()
+    }
+
+    foo()
+
+    return "OK"
+}
diff --git a/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
index f401e51c6d3..83ee8ffdf79 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
@@ -4812,6 +4812,16 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest("compiler/testData/codegen/box/unit/nullableUnit.kt");
         }
         
+        @TestMetadata("nullableUnitInWhen1.kt")
+        public void testNullableUnitInWhen1() throws Exception {
+            doTest("compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt");
+        }
+        
+        @TestMetadata("nullableUnitInWhen2.kt")
+        public void testNullableUnitInWhen2() throws Exception {
+            doTest("compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt");
+        }
+        
         @TestMetadata("unitClassObject.kt")
         public void testUnitClassObject() throws Exception {
             doTest("compiler/testData/codegen/box/unit/unitClassObject.kt");