From 776c7447b1ae068f8504457cf5a7f9e0f4812640 Mon Sep 17 00:00:00 2001
From: Alexey Andreev <Alexey.Andreev@jetbrains.com>
Date: Wed, 4 May 2016 17:59:20 +0300
Subject: [PATCH] JS/Inlining: in temporary variable elimination introduce
 better recognition of FQNs without side effects

---
 .../js/inline/clean/TemporaryVariableElimination.kt  | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/TemporaryVariableElimination.kt b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/TemporaryVariableElimination.kt
index fa428dd841f..3697c69783b 100644
--- a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/TemporaryVariableElimination.kt
+++ b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/TemporaryVariableElimination.kt
@@ -488,8 +488,16 @@ internal class TemporaryVariableElimination(private val root: JsStatement) {
         return (expr != null && isTrivial(expr)) || usages[name] ?: 0 == 1
     }
 
-    private fun isTrivial(expr: JsExpression) = when (expr) {
-        is JsNameRef -> expr.qualifier == null && (expr.name?.let { definitions[it] ?: 0 <= 1 } ?: false)
+    private fun isTrivial(expr: JsExpression): Boolean = when (expr) {
+        is JsNameRef -> {
+            val qualifier = expr.qualifier
+            if (qualifier == null) {
+                !expr.sideEffects || (expr.name?.let { definitions[it] ?: 0 <= 1 } ?: false)
+            }
+            else {
+                !expr.sideEffects && isTrivial(qualifier)
+            }
+        }
         is JsLiteral.JsValueLiteral -> true
         else -> false
     }