From 816a17dfc097526e236271ed47a51f3d198fd15e Mon Sep 17 00:00:00 2001
From: Alexey Andreev <konsoletyper@gmail.com>
Date: Fri, 10 Feb 2017 23:43:04 +0300
Subject: [PATCH] When Value.get() called in metaprogramming lambda and not
 assigned anywhere, capture instance anyway so that if it's a lazy value, it
 will be computed

---
 .../impl/CompositeMethodGenerator.java        |  2 ++
 .../test/MetaprogrammingTest.java             | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
index c1e91e688..054c7d0c5 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
@@ -824,6 +824,8 @@ public class CompositeMethodGenerator {
                             insn.setReceiver(var(receiver));
                             insn.setAssignee(var(instance));
                             add(insn);
+                        } else {
+                            var(instance);
                         }
                         return;
                     } else {
diff --git a/tests/src/test/java/org/teavm/metaprogramming/test/MetaprogrammingTest.java b/tests/src/test/java/org/teavm/metaprogramming/test/MetaprogrammingTest.java
index 337b35621..ca80fccd7 100644
--- a/tests/src/test/java/org/teavm/metaprogramming/test/MetaprogrammingTest.java
+++ b/tests/src/test/java/org/teavm/metaprogramming/test/MetaprogrammingTest.java
@@ -36,6 +36,7 @@ import org.teavm.metaprogramming.Value;
 import org.teavm.metaprogramming.reflect.ReflectField;
 import org.teavm.metaprogramming.reflect.ReflectMethod;
 import org.teavm.metaprogramming.test.subpackage.MetaprogrammingGenerator;
+import org.teavm.model.ValueType;
 
 @CompileTime
 @RunWith(TeaVMTestRunner.class)
@@ -395,6 +396,24 @@ public class MetaprogrammingTest {
         emit(() -> type);
     }
 
+    @Test
+    public void unassignedLazyEvaluated() {
+        withUnassignedLazy(Object.class);
+        assertEquals(23, counter);
+    }
+
+    @Meta
+    private static native void withUnassignedLazy(Class<Object> cls);
+    private static void withUnassignedLazy(ReflectClass<Object> cls) {
+        emit(() -> counter = 42);
+        Value<Object> value = lazy(() -> counter = 23);
+        emit(() -> {
+            value.get();
+        });
+    }
+
+    private static int counter = 0;
+
     static class Context {
         public int a;
         public int b;