From 989cebe79ec708e589265201b4f205ba54474975 Mon Sep 17 00:00:00 2001
From: Alexey Andreev <Alexey.Andreev@jetbrains.com>
Date: Thu, 24 Aug 2017 16:18:55 +0300
Subject: [PATCH] JS: fix bug in temporary variable eliminator

The problem was in considering `a` as trivial in following case:

```
var a = b;
```

However, that's wrong assumption, since `b` can be temporary variable
itself which is further substituted by a non-trivial expression.
---
 .../clean/TemporaryVariableElimination.kt     |  2 +-
 .../js/test/semantics/BoxJsTestGenerated.java |  6 ++++
 .../temporaryVarNonTrivial.kt                 | 31 +++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 js/js.translator/testData/box/inlineEvaluationOrder/temporaryVarNonTrivial.kt

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 75ee37ae41f..6e11fb8dc9c 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
@@ -615,7 +615,7 @@ internal class TemporaryVariableElimination(private val function: JsFunction) {
         is JsNameRef -> {
             val qualifier = expr.qualifier
             if (expr.sideEffects == SideEffectKind.PURE && (qualifier == null || isTrivial(qualifier))) {
-                true
+                expr.name !in temporary
             }
             else {
                 val name = expr.name
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
index 3883d18650e..a3c11659849 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
@@ -4484,6 +4484,12 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             doTest(fileName);
         }
 
+        @TestMetadata("temporaryVarNonTrivial.kt")
+        public void testTemporaryVarNonTrivial() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/inlineEvaluationOrder/temporaryVarNonTrivial.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("ternaryConditional.kt")
         public void testTernaryConditional() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/inlineEvaluationOrder/ternaryConditional.kt");
diff --git a/js/js.translator/testData/box/inlineEvaluationOrder/temporaryVarNonTrivial.kt b/js/js.translator/testData/box/inlineEvaluationOrder/temporaryVarNonTrivial.kt
new file mode 100644
index 00000000000..6e06fe2cf0c
--- /dev/null
+++ b/js/js.translator/testData/box/inlineEvaluationOrder/temporaryVarNonTrivial.kt
@@ -0,0 +1,31 @@
+// EXPECTED_REACHABLE_NODES: 1002
+var log = ""
+
+fun bar(): A {
+    log += "foo;"
+    return A()
+}
+
+class A {
+    fun f() {
+        log += "f;"
+    }
+
+    fun g() {
+        log += "g;"
+    }
+}
+
+inline fun <T> with(x: T, a: T.() -> Unit) = x.a()
+
+fun box(): String {
+    with(bar()) {
+        f()
+        g()
+    }
+
+    if (log != "foo;f;g;") return "fail: $log"
+
+    return "OK"
+}
+