From e8b95b971d75bbda8f8a67b79f9125fe124ac57b Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Mon, 18 Sep 2017 16:43:36 +0300
Subject: [PATCH] Make parentheses necessary for '(x op return y) op z'
 #KT-16808 Fixed

---
 .../org/jetbrains/kotlin/psi/KtPsiUtil.java    | 18 +++++++++++++-----
 .../removeUnnecessaryParentheses/elvisRhs.kt   |  5 +++++
 .../elvisRhsEmptyReturn.kt                     |  7 +++++++
 .../intentions/IntentionTestGenerated.java     | 12 ++++++++++++
 4 files changed, 37 insertions(+), 5 deletions(-)
 create mode 100644 idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt
 create mode 100644 idea/testData/intentions/removeUnnecessaryParentheses/elvisRhsEmptyReturn.kt

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java b/compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java
index 3409f30fc41..f39657bde07 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java
+++ b/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 &&
-            innerOperation != KtTokens.ELVIS &&
-            isKeepBinaryExpressionParenthesized((KtBinaryExpression) innerExpression)) {
-            return true;
+        if (innerExpression instanceof KtBinaryExpression) {
+            // '(x operator return [...]) operator ...' case
+            if (parentElement instanceof KtBinaryExpression) {
+                KtBinaryExpression innerBinary = (KtBinaryExpression) innerExpression;
+                if (innerBinary.getRight() instanceof KtReturnExpression) {
+                    return true;
+                }
+            }
+            // '(x operator y)' case
+            if (innerOperation != KtTokens.ELVIS &&
+                isKeepBinaryExpressionParenthesized((KtBinaryExpression) innerExpression)) {
+                return true;
+            }
         }
 
         int innerPriority = getPriority(innerExpression);
diff --git a/idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt b/idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt
new file mode 100644
index 00000000000..de82156154f
--- /dev/null
+++ b/idea/testData/intentions/removeUnnecessaryParentheses/elvisRhs.kt
@@ -0,0 +1,5 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+fun foo(): Boolean {
+    return <caret>("" ?: return false) in listOf("")
+}
\ No newline at end of file
diff --git a/idea/testData/intentions/removeUnnecessaryParentheses/elvisRhsEmptyReturn.kt b/idea/testData/intentions/removeUnnecessaryParentheses/elvisRhsEmptyReturn.kt
new file mode 100644
index 00000000000..0968e2bc96e
--- /dev/null
+++ b/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) {}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
index f004cf2f427..ffbee40d147 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
+++ b/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");