From 7f8b5f89527be26798548392a11e99efe3ded48d Mon Sep 17 00:00:00 2001
From: Anna Kozlova <anna.kozlova@jetbrains.com>
Date: Wed, 25 May 2016 13:09:45 +0200
Subject: [PATCH] redundant cast: process branches of conditional expressions
 with respect to expected type for functional expressions (IDEA-156480)

---
 .../src/com/intellij/psi/util/RedundantCastUtil.java  |  4 ++++
 .../lambda/redundantCast/CastInConditionalBranch.java | 11 +++++++++++
 .../daemon/lambda/LambdaRedundantCastTest.java        |  1 +
 3 files changed, 16 insertions(+)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/redundantCast/CastInConditionalBranch.java

diff --git a/java/java-psi-api/src/com/intellij/psi/util/RedundantCastUtil.java b/java/java-psi-api/src/com/intellij/psi/util/RedundantCastUtil.java
index 57c6d99f73c7..603031d375fc 100644
--- a/java/java-psi-api/src/com/intellij/psi/util/RedundantCastUtil.java
+++ b/java/java-psi-api/src/com/intellij/psi/util/RedundantCastUtil.java
@@ -663,6 +663,10 @@ public class RedundantCastUtil {
             return;
           }
         }
+
+        if (operand instanceof PsiFunctionalExpression && !castTo.equals(PsiTypesUtil.getExpectedTypeByParent(parent))) {
+          return;
+        }
       }
 
       if (arrayAccessAtTheLeftSideOfAssignment(parent, typeCast)) {
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/redundantCast/CastInConditionalBranch.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/redundantCast/CastInConditionalBranch.java
new file mode 100644
index 000000000000..6c94cd192494
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/redundantCast/CastInConditionalBranch.java
@@ -0,0 +1,11 @@
+import java.util.function.Supplier;
+
+class Test {
+  {
+    Object o = true ? ((Supplier<String>) () -> "") : null;
+    Supplier<String> s1 = true ? ((<warning descr="Casting '() -> \"\"' to 'Supplier<String>' is redundant">Supplier<String></warning>) () -> "") : null;
+    Supplier<String> s2 = true ? ((A) () -> "") : null;
+  }
+
+  interface A extends Supplier<String> {}
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaRedundantCastTest.java b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaRedundantCastTest.java
index bb6a9c97548d..5a821021f2ec 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaRedundantCastTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaRedundantCastTest.java
@@ -80,6 +80,7 @@ public class LambdaRedundantCastTest extends LightDaemonAnalyzerTestCase {
   }
 
   public void testInvalidResolveWithoutCast() { doTest();}
+  public void testCastInConditionalBranch() { doTest();}
 
   public void testRejectReturnTypeChange() throws Exception {
     doTest();