From 6047746c90f1d26282126e724ffb26043a96c94b Mon Sep 17 00:00:00 2001
From: Alexey Andreev <Alexey.Andreev@jetbrains.com>
Date: Thu, 27 Apr 2017 17:32:27 +0300
Subject: [PATCH] Fix optimization in JS BE

Don't apply while condition folding when corresponding break
statement breaks outer loop.
---
 .../js/inline/clean/WhileConditionFolding.kt  |  2 +-
 .../optimizer/WhileConditionFoldingTest.kt    |  2 ++
 .../labeledBreak.optimized.js                 | 19 +++++++++++++++++++
 .../labeledBreak.original.js                  | 19 +++++++++++++++++++
 4 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.optimized.js
 create mode 100644 js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.original.js

diff --git a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/WhileConditionFolding.kt b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/WhileConditionFolding.kt
index 5a90ada6a93..c5b863b3006 100644
--- a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/WhileConditionFolding.kt
+++ b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/WhileConditionFolding.kt
@@ -105,7 +105,7 @@ class WhileConditionFolding(val body: JsBlock) {
                 // therefore for single `break` we should return `false`.
                 is JsBreak -> {
                     val target = statement.label?.name
-                    if (label == null || label == target) JsLiteral.FALSE else null
+                    if (label == target) JsLiteral.FALSE else null
                 }
 
                 // Code like this
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/WhileConditionFoldingTest.kt b/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/WhileConditionFoldingTest.kt
index c3f7fddd79e..86e5e6fa4b8 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/WhileConditionFoldingTest.kt
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/optimizer/WhileConditionFoldingTest.kt
@@ -40,4 +40,6 @@ class WhileConditionFoldingTest : BasicOptimizerTest("while-condition-folding")
     @Test fun doWhileWithNestedContinue() = box()
 
     @Test fun labeledContinueInNestedLoop() = box()
+
+    @Test fun labeledBreak() = box()
 }
\ No newline at end of file
diff --git a/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.optimized.js b/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.optimized.js
new file mode 100644
index 00000000000..b7c64c8cb39
--- /dev/null
+++ b/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.optimized.js
@@ -0,0 +1,19 @@
+function box() {
+    var i = 0;
+    var j = 0;
+    var log = "";
+    outer: while (i < 10) {
+        while (j < 10) {
+            if (i + j >= 3) {
+                break outer;
+            }
+            log += i + "," + j + ";";
+            j++;
+        }
+        i++;
+    }
+
+    if (log != "0,0;0,1;0,2;") return "fail: " + log;
+
+    return "OK"
+}
\ No newline at end of file
diff --git a/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.original.js b/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.original.js
new file mode 100644
index 00000000000..b7c64c8cb39
--- /dev/null
+++ b/js/js.translator/testData/js-optimizer/while-condition-folding/labeledBreak.original.js
@@ -0,0 +1,19 @@
+function box() {
+    var i = 0;
+    var j = 0;
+    var log = "";
+    outer: while (i < 10) {
+        while (j < 10) {
+            if (i + j >= 3) {
+                break outer;
+            }
+            log += i + "," + j + ";";
+            j++;
+        }
+        i++;
+    }
+
+    if (log != "0,0;0,1;0,2;") return "fail: " + log;
+
+    return "OK"
+}
\ No newline at end of file