From ee74342fbed127379adc04dbfd6fff8621ad75ad Mon Sep 17 00:00:00 2001
From: Alexey Andreev <Alexey.Andreev@jetbrains.com>
Date: Tue, 10 Jan 2017 12:35:04 +0300
Subject: [PATCH] JS: fix compiler crash when optimizing JS AST with empty
 do..while statement. See KT-15513

---
 .../breakContinueInExpressions/breakFromOuter.kt          | 3 ---
 .../kotlin/js/inline/clean/DoWhileGuardElimination.kt     | 2 +-
 .../js/test/optimizer/DoWhileGuardEliminationTest.kt      | 2 ++
 .../js/test/semantics/JsCodegenBoxTestGenerated.java      | 8 +-------
 .../do-while-guard-elimination/emptyDoWhile.optimized.js  | 5 +++++
 .../do-while-guard-elimination/emptyDoWhile.original.js   | 5 +++++
 6 files changed, 14 insertions(+), 11 deletions(-)
 create mode 100644 js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.optimized.js
 create mode 100644 js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.original.js

diff --git a/compiler/testData/codegen/box/controlStructures/breakContinueInExpressions/breakFromOuter.kt b/compiler/testData/codegen/box/controlStructures/breakContinueInExpressions/breakFromOuter.kt
index af81659efc5..7566e7c14a9 100644
--- a/compiler/testData/codegen/box/controlStructures/breakContinueInExpressions/breakFromOuter.kt
+++ b/compiler/testData/codegen/box/controlStructures/breakContinueInExpressions/breakFromOuter.kt
@@ -1,6 +1,3 @@
-// TODO: muted automatically, investigate should it be ran for JS or not
-// IGNORE_BACKEND: JS
-
 fun box(): String {
     OUTER@while (true) {
         var x = ""
diff --git a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/DoWhileGuardElimination.kt b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/DoWhileGuardElimination.kt
index 8e1490948bb..4e837e41c57 100644
--- a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/DoWhileGuardElimination.kt
+++ b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/DoWhileGuardElimination.kt
@@ -62,7 +62,7 @@ internal class DoWhileGuardElimination(private val root: JsStatement) {
                 val body = x.body
                 val guard = when (body) {
                     is JsBlock -> {
-                        val firstStatement = body.statements.first()
+                        val firstStatement = body.statements.firstOrNull()
                         if (firstStatement is JsLabel && body.statements.size == 1) {
                             firstStatement
                         }
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/DoWhileGuardEliminationTest.kt b/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/DoWhileGuardEliminationTest.kt
index 01183662217..a12acbf6914 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/DoWhileGuardEliminationTest.kt
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/DoWhileGuardEliminationTest.kt
@@ -24,4 +24,6 @@ class DoWhileGuardEliminationTest : BasicOptimizerTest("do-while-guard-eliminati
     @Test fun innerContinue() = box()
 
     @Test fun innerBreakInLoopWithoutLabel() = box()
+
+    @Test fun emptyDoWhile() = box()
 }
\ No newline at end of file
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
index 1b66e22edc3..e8c78ed62f9 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
@@ -5033,13 +5033,7 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             @TestMetadata("breakFromOuter.kt")
             public void testBreakFromOuter() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/controlStructures/breakContinueInExpressions/breakFromOuter.kt");
-                try {
-                    doTest(fileName);
-                }
-                catch (Throwable ignore) {
-                    return;
-                }
-                throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
+                doTest(fileName);
             }
 
             @TestMetadata("breakInDoWhile.kt")
diff --git a/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.optimized.js b/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.optimized.js
new file mode 100644
index 00000000000..52a535d885f
--- /dev/null
+++ b/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.optimized.js
@@ -0,0 +1,5 @@
+function box() {
+    do {
+    } while (false);
+    return "OK"
+}
\ No newline at end of file
diff --git a/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.original.js b/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.original.js
new file mode 100644
index 00000000000..52a535d885f
--- /dev/null
+++ b/js/js.translator/testData/js-optimizer/do-while-guard-elimination/emptyDoWhile.original.js
@@ -0,0 +1,5 @@
+function box() {
+    do {
+    } while (false);
+    return "OK"
+}
\ No newline at end of file