From 30b12e3e25d17f570ce51ac3fb8246d04eb960c9 Mon Sep 17 00:00:00 2001
From: Anna Kozlova <anna.kozlova@jetbrains.com>
Date: Tue, 30 Sep 2014 14:57:30 +0200
Subject: [PATCH] new inference: same parametrization check tweaked
 (IDEA-130519)

---
 .../graphInference/InferenceSession.java      |  2 +-
 ...onCheckTakesTypeParametersIntoAccount.java | 28 +++++++++++++++++++
 .../lambda/NewLambdaHighlightingTest.java     |  4 +++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/SameParametrizationCheckTakesTypeParametersIntoAccount.java

diff --git a/java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java b/java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java
index 66a624d4b61a..542d5b7e7299 100644
--- a/java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java
+++ b/java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java
@@ -549,7 +549,7 @@ public class InferenceSession {
       final Processor<Pair<PsiType, PsiType>> differentParameterizationProcessor = new Processor<Pair<PsiType, PsiType>>() {
         @Override
         public boolean process(Pair<PsiType, PsiType> pair) {
-          return pair.first == null || pair.second == null || pair.first.equals(pair.second);
+          return pair.first == null || pair.second == null || !TypesDistinctProver.provablyDistinct(pair.first, pair.second);
         }
       };
       if (InferenceIncorporationPhase.findParameterizationOfTheSameGenericClass(bounds, differentParameterizationProcessor)) return true;
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/SameParametrizationCheckTakesTypeParametersIntoAccount.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/SameParametrizationCheckTakesTypeParametersIntoAccount.java
new file mode 100644
index 000000000000..3f8e4ea19a9a
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/SameParametrizationCheckTakesTypeParametersIntoAccount.java
@@ -0,0 +1,28 @@
+import java.util.Optional;
+
+interface Work<T> {
+  T execute();
+}
+
+interface Result {}
+
+class ResultImpl implements Result {}
+
+class Provider {
+  <T> T doWork(Work<T> work) {
+    return work.execute();
+  }
+}
+
+class Main {
+  public static void main(String[] args) {
+    final Provider provider = new Provider();
+    final Optional<Result> result = provider.doWork(() -> {
+      if (args.length > 1) {
+        return Optional.of(new ResultImpl());
+      } else {
+        return Optional.of(new ResultImpl());
+      }
+    });
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java
index d6153e6b3d84..7ddecf408499 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java
@@ -134,6 +134,10 @@ public class NewLambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testSameParametrizationCheckTakesTypeParametersIntoAccount() throws Exception {
+    doTest();
+  }
+
   @Bombed(month = Calendar.OCTOBER, day = 30)
   public void testCheckedExceptionsConstraintsSubstitutions() throws Exception {
     doTest();