lambda inference: conditional expressions in returns (IDEA-174301)

skip conditionals and parenthesis during find top expression

java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSessionContainer.java

@@ -165,6 +165,9 @@ public class InferenceSessionContainer {
             gParent = returnContainer.getParent();
           }
         }
+        if (gParent instanceof PsiConditionalExpression) {
+          gParent = PsiUtil.skipParenthesizedExprUp(gParent.getParent());
+        }
         if (gParent instanceof PsiLambdaExpression) {
           final PsiCall call = PsiTreeUtil.getParentOfType(gParent, PsiCall.class);
           if (call != null) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/ConditionalExpressionInLambdaReturns.java

@@ -0,0 +1,20 @@
+
+import java.util.function.Function;
+
+interface Container<T> {
+  static <Q> Function<Q, Container<Q>> typeTester(Container<Q> c, final Container<Q> one) {
+    return funcWithString(input -> c.match(aa -> (true ? (zero()) : one)));
+  }
+
+  static <S> Function<S, Container<S>> funcWithString(Function<S, Container<S>> f) {
+    return null;
+  }
+
+  default <R> R match(Function<T, R> f) {
+    return null;
+  }
+
+  static <T> Container<T> zero() {
+    return null;
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java

@@ -158,6 +158,7 @@ public class NewLambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testIgnoreStandaloneExpressionsInLambdaReturnForNestedCalls() { doTest(); }
   public void testArrayNotAFunctionalInterface() { doTest(); }
   public void testRawSubstitutionForInterfaceMethod() { doTest(); }
+  public void testConditionalExpressionInLambdaReturns() { doTest(); }
 
   private void doTest() {
     IdeaTestUtil.setTestVersion(JavaSdkVersion.JDK_1_8, getModule(), getTestRootDisposable());