From b0553ff651611e17dc0905498357a8056825a3fd Mon Sep 17 00:00:00 2001
From: Stepan Koltsov <stepan.koltsov@jetbrains.com>
Date: Sat, 9 Jun 2012 23:25:41 +0400
Subject: [PATCH] properly handle empty lines in REPL

---
 .../types/expressions/ExpressionTypingServices.java  | 12 ++++++++----
 compiler/testData/codegen/script/empty.ktscript      |  2 ++
 compiler/testData/repl/empty.repl                    |  8 ++++++++
 .../org/jetbrains/jet/codegen/ScriptGenTest.java     |  4 ++++
 .../org/jetbrains/jet/repl/ReplInterpreterTest.java  |  5 +++++
 .../org/jetbrains/jet/repl/ReplSessionTestFile.java  |  8 ++++++--
 6 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 compiler/testData/codegen/script/empty.ktscript
 create mode 100644 compiler/testData/repl/empty.repl

diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ExpressionTypingServices.java b/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ExpressionTypingServices.java
index 2c1c53a319f..da74017946c 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ExpressionTypingServices.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ExpressionTypingServices.java
@@ -177,9 +177,6 @@ public class ExpressionTypingServices {
     @Nullable
     public JetType getBlockReturnedType(@NotNull JetScope outerScope, @NotNull JetBlockExpression expression, @NotNull CoercionStrategy coercionStrategyForLastExpression, ExpressionTypingContext context, BindingTrace trace) {
         List<JetElement> block = expression.getStatements();
-        if (block.isEmpty()) {
-            return DataFlowUtils.checkType(JetStandardClasses.getUnitType(), expression, context);
-        }
 
         DeclarationDescriptor containingDescriptor = outerScope.getContainingDeclaration();
         if (containingDescriptor instanceof ScriptDescriptor) {
@@ -192,7 +189,14 @@ public class ExpressionTypingServices {
         WritableScope scope = new WritableScopeImpl(
                 outerScope, containingDescriptor, new TraceBasedRedeclarationHandler(context.trace), "getBlockReturnedType");
         scope.changeLockLevel(WritableScope.LockLevel.BOTH);
-        JetType r = getBlockReturnedTypeWithWritableScope(scope, block, coercionStrategyForLastExpression, context, trace);
+
+        JetType r;
+        if (block.isEmpty()) {
+            r = DataFlowUtils.checkType(JetStandardClasses.getUnitType(), expression, context);
+        }
+        else {
+            r = getBlockReturnedTypeWithWritableScope(scope, block, coercionStrategyForLastExpression, context, trace);
+        }
         scope.changeLockLevel(WritableScope.LockLevel.READING);
 
         if (containingDescriptor instanceof ScriptDescriptor) {
diff --git a/compiler/testData/codegen/script/empty.ktscript b/compiler/testData/codegen/script/empty.ktscript
new file mode 100644
index 00000000000..1378a17d91c
--- /dev/null
+++ b/compiler/testData/codegen/script/empty.ktscript
@@ -0,0 +1,2 @@
+
+// expected: rv: null
diff --git a/compiler/testData/repl/empty.repl b/compiler/testData/repl/empty.repl
new file mode 100644
index 00000000000..cb1f405f180
--- /dev/null
+++ b/compiler/testData/repl/empty.repl
@@ -0,0 +1,8 @@
+>>>
+null
+>>> 101
+101
+>>>
+null
+>>> 102
+102
diff --git a/compiler/tests/org/jetbrains/jet/codegen/ScriptGenTest.java b/compiler/tests/org/jetbrains/jet/codegen/ScriptGenTest.java
index 70a2b8f5954..40aad5cfa94 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/ScriptGenTest.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/ScriptGenTest.java
@@ -82,4 +82,8 @@ public class ScriptGenTest extends CodegenTestCase {
         blackBoxFile("script/parameterClosure.ktscript");
     }
 
+    public void testEmpty() {
+        blackBoxFile("script/empty.ktscript");
+    }
+
 }
diff --git a/compiler/tests/org/jetbrains/jet/repl/ReplInterpreterTest.java b/compiler/tests/org/jetbrains/jet/repl/ReplInterpreterTest.java
index 7f602efd14d..f6db5a44202 100644
--- a/compiler/tests/org/jetbrains/jet/repl/ReplInterpreterTest.java
+++ b/compiler/tests/org/jetbrains/jet/repl/ReplInterpreterTest.java
@@ -92,5 +92,10 @@ public class ReplInterpreterTest {
         testFile("twoClosures.repl");
     }
 
+    @Test
+    public void empty() {
+        testFile("empty.repl");
+    }
+
 
 }
diff --git a/compiler/tests/org/jetbrains/jet/repl/ReplSessionTestFile.java b/compiler/tests/org/jetbrains/jet/repl/ReplSessionTestFile.java
index 3336e518a94..fa49700a66f 100644
--- a/compiler/tests/org/jetbrains/jet/repl/ReplSessionTestFile.java
+++ b/compiler/tests/org/jetbrains/jet/repl/ReplSessionTestFile.java
@@ -26,6 +26,8 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * @author Stepan Koltsov
@@ -66,10 +68,12 @@ public class ReplSessionTestFile {
                 return new ReplSessionTestFile(list);
             }
 
-            if (!odd.startsWith(">>> ")) {
+            Pattern pattern = Pattern.compile(">>>( |$)(.*)");
+            Matcher matcher = pattern.matcher(odd);
+            if (!matcher.matches()) {
                 throw new IllegalStateException("odd lines must start with >>>");
             }
-            String code = odd.substring(4);
+            String code = matcher.group(2);
 
             String even = reader.readLine();
             if (even == null) {