disable trivial functional expression for body with returns (IDEA-173436)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/trivialFunctionalExpressionUsage/beforeBlockLambdaWithReturnInside.java

@@ -0,0 +1,12 @@
+// "Replace method call on lambda with lambda body" "false"
+
+class Test {
+    void foo() {
+        Runnable r = () -> {
+            if (true) return;
+            System.out.println("");
+        };
+        r.r<caret>un();
+        System.out.println("");
+    }
+}

plugins/InspectionGadgets/src/com/intellij/codeInspection/TrivialFunctionalExpressionUsageInspection.java

@@ -68,8 +68,17 @@ public class TrivialFunctionalExpressionUsageInspection extends BaseJavaBatchLoc
             return false;
           }
 
-          if (!returnExpressions.isEmpty() && callParent instanceof PsiLocalVariable) {
-            return true;
+          if (!returnExpressions.isEmpty()) {
+            if (callParent instanceof PsiLocalVariable) {
+              return true;
+            }
+          }
+          else {
+            PsiReturnStatement[] returnStatements = PsiUtil.findReturnStatements((PsiCodeBlock)body);
+            if (returnStatements.length > 0) {
+              //accept redundant return which would be deleted
+              return returnStatements.length == 1 && returnStatements[0] == statements[statements.length - 1];
+            }
           }
 
           return (callParent instanceof PsiStatement && !(callParent instanceof PsiLoopStatement)) ||