From c227e6015080a1dd5ac256b4faeafa11328be083 Mon Sep 17 00:00:00 2001
From: Kirill Rakhman <kirill.rakhman@jetbrains.com>
Date: Tue, 12 Mar 2024 14:38:00 +0100
Subject: [PATCH] [FIR] Fix resolution of LHS of augmented assignment operator
 call

Resolve it like a receiver of a call.
This makes the resolution result consistent with the equivalent
function call.

The K1 difference is covered by KT-66453.

#KT-66504 Fixed
---
 .../body/resolve/FirExpressionsResolveTransformer.kt           | 3 ++-
 .../diagnostics/tests/resolve/operatorAndInfixResolve.fir.kt   | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt
index 10ca607d05a..b3b486f5823 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt
@@ -629,7 +629,8 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
 
         assignmentOperatorStatement.transformAnnotations(transformer, ResolutionMode.ContextIndependent)
         dataFlowAnalyzer.enterCallArguments(assignmentOperatorStatement, listOf(assignmentOperatorStatement.rightArgument))
-        val leftArgument = assignmentOperatorStatement.leftArgument.transformSingle(transformer, ResolutionMode.ContextIndependent)
+        val leftArgument = assignmentOperatorStatement.leftArgument
+            .transformAsExplicitReceiver(ResolutionMode.ReceiverResolution, isUsedAsGetClassReceiver = false)
         val rightArgument = assignmentOperatorStatement.rightArgument.transformSingle(transformer, ResolutionMode.ContextDependent)
         dataFlowAnalyzer.exitCallArguments()
 
diff --git a/compiler/testData/diagnostics/tests/resolve/operatorAndInfixResolve.fir.kt b/compiler/testData/diagnostics/tests/resolve/operatorAndInfixResolve.fir.kt
index 787972dcc39..ac90bfaf376 100644
--- a/compiler/testData/diagnostics/tests/resolve/operatorAndInfixResolve.fir.kt
+++ b/compiler/testData/diagnostics/tests/resolve/operatorAndInfixResolve.fir.kt
@@ -59,7 +59,7 @@ fun test() {
     X()
 
     X.<!UNRESOLVED_REFERENCE!>plusAssign<!>("")
-    X += ""
+    X <!UNRESOLVED_REFERENCE!>+=<!> ""
     X<!NO_GET_METHOD!>[X]<!> += ""
 
     // Must resolve to property