From e6e46809deb50d6c1f97ce08cf2f6d3fdfb1ad32 Mon Sep 17 00:00:00 2001
From: Kirill Rakhman <kirill.rakhman@gmail.com>
Date: Sat, 20 Aug 2016 14:11:57 +0200
Subject: [PATCH] fix "Can be replaced with comparison" false positive if
 extension method called 'equals' is used Fixes #KT-13480

---
 .../ReplaceCallWithBinaryOperatorIntention.kt        | 12 +++++++++---
 .../equalsExtensionFunction.kt                       | 11 +++++++++++
 .../idea/intentions/IntentionTestGenerated.java      |  6 ++++++
 3 files changed, 26 insertions(+), 3 deletions(-)
 create mode 100644 idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt

diff --git a/idea/src/org/jetbrains/kotlin/idea/intentions/conventionNameCalls/ReplaceCallWithBinaryOperatorIntention.kt b/idea/src/org/jetbrains/kotlin/idea/intentions/conventionNameCalls/ReplaceCallWithBinaryOperatorIntention.kt
index 6ab00e7c2a1..0baa079311f 100644
--- a/idea/src/org/jetbrains/kotlin/idea/intentions/conventionNameCalls/ReplaceCallWithBinaryOperatorIntention.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/intentions/conventionNameCalls/ReplaceCallWithBinaryOperatorIntention.kt
@@ -32,6 +32,8 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getLastParentOfTypeInRow
 import org.jetbrains.kotlin.resolve.calls.model.ArgumentMatch
 import org.jetbrains.kotlin.resolve.calls.model.isReallySuccess
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
+import org.jetbrains.kotlin.resolve.findOriginalTopMostOverriddenDescriptors
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.expressions.OperatorConventions
 import org.jetbrains.kotlin.util.OperatorNameConventions
@@ -107,16 +109,20 @@ class ReplaceCallWithBinaryOperatorIntention : SelfTargetingRangeIntention<KtDot
 
     private fun operation(calleeExpression: KtSimpleNameExpression): KtSingleValueToken? {
         val identifier = calleeExpression.getReferencedNameAsName()
+        val dotQualified = calleeExpression.parent?.parent as? KtDotQualifiedExpression ?: return null
         return when (identifier) {
             OperatorNameConventions.EQUALS -> {
-                val prefixExpression = calleeExpression.parent?.parent?.getWrappingPrefixExpressionIfAny()
+                val resolvedCall = dotQualified.toResolvedCall(BodyResolveMode.PARTIAL) ?: return null
+                val overriddenDescriptors = resolvedCall.resultingDescriptor.findOriginalTopMostOverriddenDescriptors()
+                if (overriddenDescriptors.none { it.fqNameUnsafe.asString() == "kotlin.Any.equals" }) return null
+
+                val prefixExpression = dotQualified.getWrappingPrefixExpressionIfAny()
                 if (prefixExpression != null && prefixExpression.operationToken == KtTokens.EXCL) KtTokens.EXCLEQ
                 else KtTokens.EQEQ
             }
             OperatorNameConventions.COMPARE_TO -> {
                 // callee -> call -> DotQualified -> Binary
-                val dotQualified = calleeExpression.parent?.parent
-                val binaryParent = dotQualified?.parent as? KtBinaryExpression ?: return null
+                val binaryParent = dotQualified.parent as? KtBinaryExpression ?: return null
                 val notZero = when {
                     binaryParent.right?.text == "0" -> binaryParent.left
                     binaryParent.left?.text == "0" -> binaryParent.right
diff --git a/idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt b/idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt
new file mode 100644
index 00000000000..cf6eeae1287
--- /dev/null
+++ b/idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt
@@ -0,0 +1,11 @@
+// IS_APPLICABLE: false
+
+class Foo
+
+fun Foo?.equals(other: Foo?) = true
+
+fun bar(f1: Foo?, f2: Foo?) {
+    if (f1.equals<caret>(f2)) {
+
+    }
+}
\ 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 270fd38ab15..5d28a6fd0a4 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
@@ -2807,6 +2807,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("equalsExtensionFunction.kt")
+            public void testEqualsExtensionFunction() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("extensionFunction.kt")
             public void testExtensionFunction() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/extensionFunction.kt");