From e7cef797099ccb9ef0844796ca2497d53665f8f9 Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <Mikhail.Glukhikh@jetbrains.com>
Date: Thu, 27 Oct 2016 14:56:08 +0300
Subject: [PATCH] If then to elvis: now not applicable for is with type
 unrelated to original #KT-14520 Fixed

---
 .../intentions/IfThenToElvisIntention.kt             |  6 +++++-
 .../ifThenToElvis/isCheckForUnrelatedType.kt         | 12 ++++++++++++
 .../idea/intentions/IntentionTestGenerated.java      |  6 ++++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 idea/testData/intentions/branched/ifThenToElvis/isCheckForUnrelatedType.kt

diff --git a/idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt b/idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt
index 877bce6f667..19ec0521e4e 100644
--- a/idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt
@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.resolve.calls.callUtil.getType
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode.Companion.PARTIAL
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.typeUtil.TypeNullability
+import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 import org.jetbrains.kotlin.types.typeUtil.nullability
 
 class IfThenToElvisInspection : IntentionBasedInspection<KtIfExpression>(IfThenToElvisIntention::class)
@@ -69,7 +70,10 @@ class IfThenToElvisIntention : SelfTargetingOffsetIndependentIntention<KtIfExpre
                 else -> false
             }
             is KtIsExpression -> {
-                if (!context[BindingContext.TYPE, condition.typeReference].isNotNull()) return false
+                val targetType = context[BindingContext.TYPE, condition.typeReference] ?: return false
+                if (!targetType.isNotNull()) return false
+                val originalType = condition.leftHandSide.getType(context) ?: return false
+                if (!targetType.isSubtypeOf(originalType)) return false
 
                 when (condition.isNegated) {
                     true -> checkedExpression.clausesReplaceableByElvis(thenClause, elseClause, context)
diff --git a/idea/testData/intentions/branched/ifThenToElvis/isCheckForUnrelatedType.kt b/idea/testData/intentions/branched/ifThenToElvis/isCheckForUnrelatedType.kt
new file mode 100644
index 00000000000..d5995260f0a
--- /dev/null
+++ b/idea/testData/intentions/branched/ifThenToElvis/isCheckForUnrelatedType.kt
@@ -0,0 +1,12 @@
+// IS_APPLICABLE: false
+
+interface A
+interface B
+
+fun prepare(x: A) = x
+fun use(x: A) {}
+
+fun test(x: A) {
+    val xx = <caret>if (x is B) x else prepare(x)
+    use(xx)
+}
\ 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 dbdfcb338f2..3098e46584c 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
@@ -1308,6 +1308,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("isCheckForUnrelatedType.kt")
+            public void testIsCheckForUnrelatedType() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/isCheckForUnrelatedType.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("isCheckWithSelector.kt")
             public void testIsCheckWithSelector() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/isCheckWithSelector.kt");