Make parentheses necessary for '(x op return y) op z' #KT-16808 Fixed

compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java

@@ -530,11 +530,19 @@ public class KtPsiUtil {
             return false;
         }
 
-        // '(x operator y)' case
+        if (innerExpression instanceof KtBinaryExpression) {
-        if (innerExpression instanceof KtBinaryExpression &&
+            // '(x operator return [...]) operator ...' case
-            innerOperation != KtTokens.ELVIS &&
+            if (parentElement instanceof KtBinaryExpression) {
-            isKeepBinaryExpressionParenthesized((KtBinaryExpression) innerExpression)) {
+                KtBinaryExpression innerBinary = (KtBinaryExpression) innerExpression;
-            return true;
+                if (innerBinary.getRight() instanceof KtReturnExpression) {
+                    return true;
+                }
+            }
+            // '(x operator y)' case
+            if (innerOperation != KtTokens.ELVIS &&
+                isKeepBinaryExpressionParenthesized((KtBinaryExpression) innerExpression)) {
+                return true;
+            }
         }
 
         int innerPriority = getPriority(innerExpression);

idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+fun foo(): Boolean {
+    return <caret>("" ?: return false) in listOf("")
+}

idea/testData/intentions/removeUnnecessaryParentheses/elvisRhsEmptyReturn.kt

@@ -0,0 +1,7 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+fun foo() {
+    bar(<caret>("" ?: return) in listOf(""))
+}
+
+fun bar(arg: Boolean) {}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -13412,6 +13412,18 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("elvisRhs.kt")
+        public void testElvisRhs() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("elvisRhsEmptyReturn.kt")
+        public void testElvisRhsEmptyReturn() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeUnnecessaryParentheses/elvisRhsEmptyReturn.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("necessaryParentheses1.kt")
         public void testNecessaryParentheses1() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeUnnecessaryParentheses/necessaryParentheses1.kt");