From 33a26d456be26341ada729056c2f02882eb9ae4c Mon Sep 17 00:00:00 2001
From: kzc <kzc@users.noreply.github.com>
Date: Sun, 5 Mar 2017 16:15:13 +0800
Subject: [PATCH] patch up #1543 for harmony

fixes #1537
---
 lib/compress.js                |  2 +
 test/compress/collapse_vars.js | 78 ++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/lib/compress.js b/lib/compress.js
index dfc7e21f405..1442113ae17 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -549,6 +549,7 @@ merge(Compressor.prototype, {
                     if (var_decl.value.is_constant()) {
                         var ctt = new TreeTransformer(function(node) {
                             if (node === ref
+                                && !ctt.find_parent(AST_Destructuring)
                                 && !ctt.find_parent(AST_ForIn)) {
                                 return replace_var(node, ctt.parent(), true);
                             }
@@ -581,6 +582,7 @@ merge(Compressor.prototype, {
                             if (unwind) return node;
                             var parent = tt.parent();
                             if (node instanceof AST_Lambda
+                                || node instanceof AST_Destructuring
                                 || node instanceof AST_Try
                                 || node instanceof AST_With
                                 || node instanceof AST_Case
diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index c8fa046051b..6d9961ff463 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -1343,3 +1343,81 @@ issue_1537_for_of: {
         for (k of {prop: 'val'});
     }
 }
+
+issue_1537_destructuring_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var x = 1, y = 2;
+        [x] = [y];
+    }
+    expect: {
+        var x = 1;
+        [x] = [2];
+    }
+}
+
+issue_1537_destructuring_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var x = foo();
+        [x] = [1];
+    }
+    expect: {
+        var x = foo();
+        [x] = [1];
+    }
+}
+
+issue_1537_destructuring_3: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var x = Math.random();
+        ({p: x = 9} = {v: 1});
+    }
+    expect: {
+        var x = Math.random();
+        ({p: x = 9} = {v: 1});
+    }
+}
+
+issue_1537_destructuring_for_in: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var x = 1, y = 2;
+        (function() {
+            for ([[x], y] in a);
+        })();
+    }
+    expect: {
+        var x = 1, y = 2;
+        (function() {
+            for ([[x], y] in a);
+        })();
+    }
+}
+
+issue_1537_destructuring_for_of: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var x = 1, y = 2;
+        (function() {
+            for ([[x], y] of a);
+        })();
+    }
+    expect: {
+        var x = 1, y = 2;
+        (function() {
+            for ([[x], y] of a);
+        })();
+    }
+}