Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

55 files changed, 2201 insertions, 0 deletions

diff --git a/js/src/tests/non262/lexical-conventions/browser.js b/js/src/tests/non262/lexical-conventions/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical-conventions/browser.js
diff --git a/js/src/tests/non262/lexical-conventions/lexical-001.js b/js/src/tests/non262/lexical-conventions/lexical-001.js
new file mode 100644
index 0000000000..308b7a2a82
--- /dev/null
+++ b/js/src/tests/non262/lexical-conventions/lexical-001.js
@@ -0,0 +1,146 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+/*
+ * Date: 26 November 2000
+ *
+ *SUMMARY: Testing numeric literals that begin with 0.
+ *This test arose from Bugzilla bug 49233.
+ *The best explanation is from jsscan.c:               
+ *
+ *     "We permit 08 and 09 as decimal numbers, which makes
+ *     our behaviour a superset of the ECMA numeric grammar. 
+ *     We might not always be so permissive, so we warn about it."
+ *
+ *Thus an expression 010 will evaluate, as always, as an octal (to 8).
+ *However, 018 will evaluate as a decimal, to 18. Even though the
+ *user began the expression as an octal, he later used a non-octal
+ *digit. We forgive this and assume he intended a decimal. If the
+ *JavaScript "strict" option is set though, we will give a warning.
+ */
+
+//-------------------------------------------------------------------------------------------------
+var BUGNUMBER = '49233';
+var summary = 'Testing numeric literals that begin with 0';
+var statprefix = 'Testing ';
+var quote = "'";
+var asString = new Array();
+var actual = new Array();
+var expect = new Array();
+
+
+  asString[0]='01'
+  actual[0]=01
+  expect[0]=1
+
+  asString[1]='07'
+  actual[1]=07
+  expect[1]=7
+
+  asString[2]='08'
+  actual[2]=08
+  expect[2]=8
+
+  asString[3]='09'
+  actual[3]=09
+  expect[3]=9
+
+  asString[4]='010'
+  actual[4]=010
+  expect[4]=8
+
+  asString[5]='017'
+  actual[5]=017
+  expect[5]=15
+
+  asString[6]='018'
+  actual[6]=018
+  expect[6]=18
+
+  asString[7]='019'
+  actual[7]=019
+  expect[7]=19
+
+  asString[8]='079'
+  actual[8]=079
+  expect[8]=79
+
+  asString[9]='0079'
+  actual[9]=0079
+  expect[9]=79
+
+  asString[10]='099'
+  actual[10]=099
+  expect[10]=99
+
+  asString[11]='0099'
+  actual[11]=0099
+  expect[11]=99
+
+  asString[12]='000000000077'
+  actual[12]=000000000077
+  expect[12]=63
+
+  asString[13]='000000000078'
+  actual[13]=000000000078
+  expect[13]=78
+
+  asString[14]='0000000000770000'
+  actual[14]=0000000000770000
+  expect[14]=258048
+
+  asString[15]='0000000000780000'
+  actual[15]=0000000000780000
+  expect[15]=780000
+
+  asString[16]='0765432198'
+  actual[16]=0765432198
+  expect[16]=765432198
+
+  asString[17]='00076543219800'
+  actual[17]=00076543219800
+  expect[17]=76543219800
+
+  asString[18]='0000001001007'
+  actual[18]=0000001001007
+  expect[18]=262663
+
+  asString[19]='0000001001009'
+  actual[19]=0000001001009
+  expect[19]=1001009
+
+  asString[20]='070'
+  actual[20]=070
+  expect[20]=56
+
+  asString[21]='080'
+  actual[21]=080
+  expect[21]=80
+
+
+
+//-------------------------------------------------------------------------------------------------
+  test();
+//-------------------------------------------------------------------------------------------------
+
+
+function showStatus(msg)
+{
+  return (statprefix  + quote  +  msg  + quote);
+}
+
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+
+
+  for (i=0; i !=asString.length; i++)
+  {
+    reportCompare (expect[i], actual[i], showStatus(asString[i]));
+  }
+}
diff --git a/js/src/tests/non262/lexical-conventions/regress-177314.js b/js/src/tests/non262/lexical-conventions/regress-177314.js
new file mode 100644
index 0000000000..ce677b77a4
--- /dev/null
+++ b/js/src/tests/non262/lexical-conventions/regress-177314.js
@@ -0,0 +1,73 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ *
+ * Date:    30 Oct 2002
+ * SUMMARY: '\400' should lex as a 2-digit octal escape + '0'
+ * See http://bugzilla.mozilla.org/show_bug.cgi?id=177314
+ *
+ * Bug was that Rhino interpreted '\400' as a 3-digit octal escape. As such
+ * it is invalid, since octal escapes may only run from '\0' to '\377'. But
+ * the lexer should interpret this as '\40' + '0' instead, and throw no error.
+ *
+ */
+//-----------------------------------------------------------------------------
+var UBound = 0;
+var BUGNUMBER = 177314;
+var summary = "'\\" + "400' should lex as a 2-digit octal escape + '0'";
+var status = '';
+var statusitems = [];
+var actual = '';
+var actualvalues = [];
+var expect= '';
+var expectedvalues = [];
+
+
+// the last valid octal escape is '\377', which should equal hex escape '\xFF'
+status = inSection(1);
+actual = '\377';
+expect = '\xFF';
+addThis();
+
+// now exercise the lexer by going one higher in the last digit
+status = inSection(2);
+actual = '\378';
+expect = '\37' + '8';
+addThis();
+
+// trickier: 400 is a valid octal number, but '\400' isn't a valid octal escape
+status = inSection(3);
+actual = '\400';
+expect = '\40' + '0';
+addThis();
+
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+
+
+function addThis()
+{
+  statusitems[UBound] = status;
+  actualvalues[UBound] = actual;
+  expectedvalues[UBound] = expect;
+  UBound++;
+}
+
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus(summary);
+
+  for (var i=0; i<UBound; i++)
+  {
+    reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]);
+  }
+}
diff --git a/js/src/tests/non262/lexical-conventions/regress-469940.js b/js/src/tests/non262/lexical-conventions/regress-469940.js
new file mode 100644
index 0000000000..d8169671c6
--- /dev/null
+++ b/js/src/tests/non262/lexical-conventions/regress-469940.js
@@ -0,0 +1,35 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 469940;
+var summary = 'Do not insert semi-colon after var with multiline initializer';
+var actual = '';
+var expect = '';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+ 
+  expect = 'SyntaxError: unexpected token: identifier';
+
+  var s = 'var x = function f() { \n return 42; } print(x);';
+
+  try
+  {
+    eval(s);
+  }
+  catch(ex)
+  {
+    actual = ex + '';
+  }
+  reportCompare(expect, actual, summary);
+}
diff --git a/js/src/tests/non262/lexical-conventions/shell.js b/js/src/tests/non262/lexical-conventions/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical-conventions/shell.js
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-arguments.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-arguments.js
new file mode 100644
index 0000000000..efc263b66f
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-arguments.js
@@ -0,0 +1,10 @@
+// Test that Annex B function interaction with 'arguments'.
+
+(function() {
+  assertEq(typeof arguments, "object");
+  { function arguments() {} }
+  assertEq(typeof arguments, "function");
+})();
+
+if (typeof reportCompare === "function")
+  reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-eval.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-eval.js
new file mode 100644
index 0000000000..9f4e4d7fe8
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-eval.js
@@ -0,0 +1,51 @@
+var log = "";
+
+function f() {
+  log += g();
+  function g() { return "outer-g"; }
+
+  var o = { g: function () { return "with-g"; } };
+  with (o) {
+    // Annex B.3.3.3 says g should be set on the nearest VariableEnvironment,
+    // and so should not change o.g.
+    eval(`{
+      function g() { return "eval-g"; }
+    }`);
+  }
+
+  log += g();
+  log += o.g();
+}
+
+f();
+
+function h() {
+  eval(`
+    // Should return true, as var bindings introduced by eval are configurable.
+    log += (delete q);
+    {
+      function q() { log += "q"; }
+      // Should return false, as lexical bindings introduced by eval are not
+      // configurable.
+      log += (delete q);
+    }
+  `);
+  return q;
+}
+
+h()();
+
+function f2() {
+  // Should not throw, just simply not synthesize an Annex B var in the eval
+  // because there's an outer const.
+  eval("{ function a() {} }");
+  const a = 1;
+}
+
+function f3() {
+  // As above, but for let.
+  eval("{ function a() {} }");
+  let a;
+}
+
+reportCompare(log, "outer-geval-gwith-gtruefalseq");
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-generators.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-generators.js
new file mode 100644
index 0000000000..dbef82bcfc
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-generators.js
@@ -0,0 +1,26 @@
+// Tests by André Bargull <andrebargull@googlemail.com>
+
+// Annex B.3.3.1
+function f1() {
+    { function* g() {} }
+    assertEq(typeof g, "undefined");
+}
+f1();
+
+// Annex B.3.3.2
+{ function* g() {} }
+assertEq(typeof g, "undefined");
+
+// Annex B.3.3.3
+function f2() {
+    eval("{ function* g() {} }");
+    assertEq(typeof g, "undefined");
+}
+f2();
+
+// Annex B.3.3.3
+eval("{ function* g() {} }");
+assertEq(typeof g, "undefined");
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-if.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-if.js
new file mode 100644
index 0000000000..ce63aeeea2
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-if.js
@@ -0,0 +1,42 @@
+var log = "";
+
+function f(x) {
+  if (x)
+    function g() { return "g0"; }
+  else
+    function g() { return "g1"; }
+
+  log += g();
+
+  if (x)
+    function g() { return "g2"; }
+  else {
+  }
+
+  log += g();
+
+  if (x) {
+  } else
+    function g() { return "g3"; }
+
+  log += g();
+
+  if (x)
+    function g() { return "g4"; }
+
+  log += g();
+}
+
+f(true);
+f(false);
+
+try {
+  eval(`
+    if (1)
+      l: function foo() {}
+  `);
+} catch (e) {
+  log += "e";
+}
+
+reportCompare(log, "g0g2g2g4g1g1g3g3e");
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-label.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-label.js
new file mode 100644
index 0000000000..0fe9f45fca
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-label.js
@@ -0,0 +1,43 @@
+function expectSyntaxError(str) {
+  var threwSyntaxError;
+  try {
+    eval(str);
+  } catch (e) {
+    threwSyntaxError = e instanceof SyntaxError;
+  }
+  assertEq(threwSyntaxError, true);
+
+  try {
+    eval('"use strict";' + str);
+  } catch (e) {
+    threwSyntaxError = e instanceof SyntaxError;
+  }
+  assertEq(threwSyntaxError, true);
+}
+
+function expectSloppyPass(str) {
+  eval(str);
+
+  try {
+    eval('"use strict";' + str);
+  } catch (e) {
+    threwSyntaxError = e instanceof SyntaxError;
+  }
+  assertEq(threwSyntaxError, true);
+}
+
+expectSloppyPass(`l: function f1() {}`);
+expectSloppyPass(`l0: l: function f1() {}`);
+expectSloppyPass(`{ f1(); l: function f1() {} }`);
+expectSloppyPass(`{ f1(); l0: l: function f1() {} }`);
+expectSloppyPass(`{ f1(); l: function f1() { return 42; } } assertEq(f1(), 42);`);
+expectSloppyPass(`eval("fe(); l: function fe() {}")`);
+expectSyntaxError(`if (1) l: function f2() {}`);
+expectSyntaxError(`if (1) {} else l: function f3() {}`);
+expectSyntaxError(`do l: function f4() {} while (0)`);
+expectSyntaxError(`while (0) l: function f5() {}`);
+expectSyntaxError(`for (;;) l: function f6() {}`);
+expectSloppyPass(`switch (1) { case 1: l: function f7() {} }`);
+expectSloppyPass(`switch (1) { case 1: assertEq(f8(), 'f8'); case 2: l: function f8() { return 'f8'; } } assertEq(f8(), 'f8');`);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-notapplicable.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-notapplicable.js
new file mode 100644
index 0000000000..4c5e2527a8
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-notapplicable.js
@@ -0,0 +1,14 @@
+// Test that functions in block that do not exhibit Annex B do not override
+// previous functions that do exhibit Annex B.
+
+function f() {
+  var outerX;
+  { function x() {1} outerX = x; }
+  { { function x() {2}; } let x; }
+  { let x; { function x() {3}; } }
+  assertEq(x, outerX);
+}
+f();
+
+if (typeof reportCompare === "function")
+  reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-parameter.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-parameter.js
new file mode 100644
index 0000000000..ae7fbe879c
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-parameter.js
@@ -0,0 +1,21 @@
+// Annex B.3.3.1 disallows Annex B lexical function behavior when redeclaring a
+// parameter.
+
+(function(f) {
+  if (true) function f() {  }
+  assertEq(f, 123);
+}(123));
+
+(function(f) {
+  { function f() {  } }
+  assertEq(f, 123);
+}(123));
+
+(function(f = 123) {
+  assertEq(f, 123);
+  { function f() { } }
+  assertEq(f, 123);
+}());
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-property.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-property.js
new file mode 100644
index 0000000000..a295de5081
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-property.js
@@ -0,0 +1,18 @@
+// |reftest| skip-if(!xulRuntime.shell)
+
+// Define a global getter without a setter.
+Object.defineProperty(this, "x", {
+  get: function () { return "get-x"; },
+  configurable: true
+});
+
+// Simulate loading a 2nd script with evaluate, else we would DEFVAR the x and
+// the above defineProperty would fail in trying to redefine a non-configurable
+// property on the global.
+evaluate(`{
+  function x() { return "fun-x"; }
+}`);
+
+// Annex B is supposed to be like an assignment. Should not blow away the
+// existing setter-less getter.
+reportCompare(x, "get-x");
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-same-name.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-same-name.js
new file mode 100644
index 0000000000..b89f91c59a
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-same-name.js
@@ -0,0 +1,7 @@
+{
+  function f() { return "inner"; }
+}
+
+function f() { return "outer"; }
+
+reportCompare(f(), "inner");
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-with.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-with.js
new file mode 100644
index 0000000000..d9bdd98dc9
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b-with.js
@@ -0,0 +1,18 @@
+var o = { f: "string-f" };
+with (o) {
+  var desc = Object.getOwnPropertyDescriptor(this, "f");
+  assertEq(desc.value, undefined);
+  assertEq(desc.writable, true);
+  assertEq(desc.enumerable, true);
+  assertEq(desc.configurable, false);
+  function f() {
+    return "fun-f";
+  }
+}
+
+// Annex B explicitly assigns to the nearest VariableEnvironment, so the
+// with-object "o" should have its property unchanged.
+assertEq(o.f, "string-f");
+assertEq(f(), "fun-f");
+
+reportCompare(true, true)
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b.js
new file mode 100644
index 0000000000..16c40774ca
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-annex-b.js
@@ -0,0 +1,31 @@
+var log = "";
+
+log += typeof f;
+
+{
+  log += f();
+
+  function f() {
+    return "f1";
+  }
+}
+
+log += f();
+
+function g() {
+  log += typeof h;
+
+  {
+    log += h();
+
+    function h() {
+      return "h1";
+    }
+  }
+
+  log += h();
+}
+
+g();
+
+reportCompare(log, "undefinedf1f1undefinedh1h1");
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-deprecated-redecl.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-deprecated-redecl.js
new file mode 100644
index 0000000000..af32be5d3d
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-deprecated-redecl.js
@@ -0,0 +1,78 @@
+{
+  assertEq(f(), 4);
+  function f() { return 3; }
+  assertEq(f(), 4);
+  function f() { return 4; }
+  assertEq(f(), 4);
+}
+
+// Annex B still works.
+assertEq(f(), 4);
+
+// The same thing with labels.
+{
+  assertEq(f(), 4);
+  function f() { return 3; }
+  assertEq(f(), 4);
+  l: function f() { return 4; }
+  assertEq(f(), 4);
+}
+
+// Annex B still works.
+assertEq(f(), 4);
+
+function test() {
+  {
+    assertEq(f(), 2);
+    function f() { return 1; }
+    assertEq(f(), 2);
+    function f() { return 2; }
+    assertEq(f(), 2);
+  }
+
+  // Annex B still works.
+  assertEq(f(), 2);
+}
+
+test();
+
+var log = '';
+
+try {
+  // Strict mode still cannot redeclare.
+  eval(`"use strict";
+  {
+    function f() { }
+    function f() { }
+  }`);
+} catch (e) {
+  assertEq(e instanceof SyntaxError, true);
+  log += 'e';
+}
+
+try {
+  // Redeclaring an explicitly 'let'-declared binding doesn't work.
+  eval(`{
+    let x = 42;
+    function x() {}
+  }`);
+} catch (e) {
+  assertEq(e instanceof SyntaxError, true);
+  log += 'e';
+}
+
+try {
+  // Redeclaring an explicitly 'const'-declared binding doesn't work.
+  eval(`{
+    const x = 42;
+    function x() {}
+  }`);
+} catch (e) {
+  assertEq(e instanceof SyntaxError, true);
+  log += 'e';
+}
+
+assertEq(log, 'eee');
+
+if ('reportCompare' in this)
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-hoisted-tdz.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-hoisted-tdz.js
new file mode 100644
index 0000000000..e5f9baf446
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-hoisted-tdz.js
@@ -0,0 +1,30 @@
+var log = "";
+try {
+  (function() {
+    {
+      let y = f();
+      function f() { y; }
+    }
+  })()
+} catch (e) {
+  log += e instanceof ReferenceError;
+}
+
+try {
+  function f() {
+    switch (1) {
+      case 0:
+        let x;
+      case 1:
+        (function() { x; })();
+    }
+  }
+  f();
+} catch (e) {
+  log += e instanceof ReferenceError;
+}
+
+assertEq(log, "truetrue");
+
+if ("reportCompare" in this)
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/block-scoped-functions-strict.js b/js/src/tests/non262/lexical-environment/block-scoped-functions-strict.js
new file mode 100644
index 0000000000..2b780d7dd1
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/block-scoped-functions-strict.js
@@ -0,0 +1,45 @@
+"use strict"
+
+var log = "";
+
+function f() {
+  return "f0";
+}
+
+log += f();
+
+{
+  log += f();
+
+  function f() {
+    return "f1";
+  }
+
+  log += f();
+}
+
+log += f();
+
+function g() {
+  function h() {
+    return "h0";
+  }
+
+  log += h();
+
+  {
+    log += h();
+
+    function h() {
+      return "h1";
+    }
+
+    log += h();
+  }
+
+  log += h();
+}
+
+g();
+
+reportCompare(log, "f0f1f1f0h0h1h1h0");
diff --git a/js/src/tests/non262/lexical-environment/browser.js b/js/src/tests/non262/lexical-environment/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/browser.js
diff --git a/js/src/tests/non262/lexical-environment/bug-1216623.js b/js/src/tests/non262/lexical-environment/bug-1216623.js
new file mode 100644
index 0000000000..cbdbe9722e
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/bug-1216623.js
@@ -0,0 +1,19 @@
+// Scoping in the head of for(let;;) statements.
+
+let x = 0;
+for (let i = 0, a = () => i; i < 4; i++) {
+  assertEq(i, x++);
+  assertEq(a(), 0);
+}
+assertEq(x, 4);
+
+x = 11;
+let q = 0;
+for (let {[++q]: r} = [0, 11, 22], s = () => r; r < 13; r++) {
+  assertEq(r, x++);
+  assertEq(s(), 11);
+}
+assertEq(x, 13);
+assertEq(q, 1);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/catch-body.js b/js/src/tests/non262/lexical-environment/catch-body.js
new file mode 100644
index 0000000000..43b9d2bfe3
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/catch-body.js
@@ -0,0 +1,19 @@
+function f() {
+  var probeParam, probeBlock;
+  let x = 'outside';
+
+  try {
+    throw [];
+  } catch ([_ = probeParam = function() { return x; }]) {
+    probeBlock = function() { return x; };
+    let x = 'inside';
+  }
+
+  assertEq(probeBlock(), 'inside');
+  assertEq(probeParam(), 'outside');
+}
+
+f();
+
+if (typeof reportCompare === 'function')
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/const-declaration-in-for-loop.js b/js/src/tests/non262/lexical-environment/const-declaration-in-for-loop.js
new file mode 100644
index 0000000000..4001220ba3
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/const-declaration-in-for-loop.js
@@ -0,0 +1,88 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = "const-declaration-in-for-loop.js";
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 1146644;
+var summary =
+  "Don't crash compiling a non-body-level for-loop whose loop declaration is " +
+  "a const";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+// Don't attempt execution as a script if we can't properly emulate it.  We
+// could perhaps use eval, but eval, while also doing global execution, is its
+// own can of messiness.  Ongoing work on for-loop scoping for lexical
+// declarations will likely make these tests redundant with other tests to be
+// added, anyway, in the very short term.
+var executeGlobalScript = typeof evaluate === "function"
+                        ? evaluate
+                        : function(s) {};
+
+for (const a1 = 3; false; )
+  continue;
+
+Function(`for (const a2 = 3; false; )
+            continue;
+         `)();
+
+if (true)
+{
+  for (const a3 = 3; false; )
+    continue;
+}
+
+Function(`if (true)
+          {
+            for (const a4 = 3; false; )
+              continue;
+          }`)();
+
+executeGlobalScript(`for (const a5 of [])
+                       continue;`);
+
+Function(`for (const a6 of [])
+            continue;`)();
+
+executeGlobalScript(`if (true)
+                     {
+                       for (const a7 of [])
+                         continue;
+                     }`);
+
+Function(`if (true)
+          {
+            for (const a8 of [])
+              continue;
+          }`)();
+
+executeGlobalScript(`for (const a9 in {})
+                       continue;`);
+
+Function(`for (const a10 in {})
+            continue;`)();
+
+executeGlobalScript(`if (true)
+                     {
+                       for (const a11 in {})
+                         continue;
+                     }`);
+
+Function(`if (true)
+          {
+            for (const a12 in {})
+              continue;
+          }`)();
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical-environment/eval-has-lexical-environment.js b/js/src/tests/non262/lexical-environment/eval-has-lexical-environment.js
new file mode 100644
index 0000000000..16ffb06d19
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/eval-has-lexical-environment.js
@@ -0,0 +1,45 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = "eval-has-lexical-environment.js"
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 1193583;
+var summary =
+  "Eval always has a lexical environment";
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+eval(`
+let foo = 42;
+const kay = foo;
+var bar = 84;
+function f() {
+  return foo + kay;
+}
+     `);
+
+(1, eval)(`
+let foo2 = 42;
+const kay2 = foo2;
+`);
+
+// Lexical declarations should not have escaped eval.
+assertEq(typeof foo, "undefined");
+assertEq(typeof kay, "undefined");
+assertEq(typeof foo2, "undefined");
+assertEq(typeof kay2, "undefined");
+
+// Eval'd functions can close over lexical bindings.
+assertEq(f(), 84);
+
+// Var can escape direct eval.
+assertEq(bar, 84);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical-environment/eval-nondefinable-function.js b/js/src/tests/non262/lexical-environment/eval-nondefinable-function.js
new file mode 100644
index 0000000000..bd5dcf7978
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/eval-nondefinable-function.js
@@ -0,0 +1,10 @@
+try {
+  eval("var shouldNotBeDefined1; function NaN(){}; var shouldNotBeDefined2;");
+} catch (e) {
+}
+
+assertEq(Object.getOwnPropertyDescriptor(this, 'shouldNotBeDefined2'), undefined);
+assertEq(Object.getOwnPropertyDescriptor(this, 'shouldNotBeDefined1'), undefined);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/for-loop-with-bindings-added-at-runtime.js b/js/src/tests/non262/lexical-environment/for-loop-with-bindings-added-at-runtime.js
new file mode 100644
index 0000000000..f6abf3d0cd
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/for-loop-with-bindings-added-at-runtime.js
@@ -0,0 +1,125 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = "for-loop-with-bindings-added-at-runtime.js";
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 1149797;
+var summary =
+  "Don't assert when freshening the scope chain for a for-loop whose head " +
+  "contains a lexical declaration, where the loop body might add more " +
+  "bindings at runtime";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+for (let x = 0; x < 9; ++x)
+  eval("var y");
+
+{
+  for (let x = 0; x < 9; ++x)
+    eval("var y");
+}
+
+function f1()
+{
+  for (let x = 0; x < 9; ++x)
+    eval("var y");
+}
+f1();
+
+function f2()
+{
+  {
+    for (let x = 0; x < 9; ++x)
+      eval("var y");
+  }
+}
+f2();
+
+for (let x = 0; x < 9; ++x)
+{
+  // deliberately inside a block statement
+  eval("var y");
+}
+
+{
+  for (let x = 0; x < 9; ++x)
+  {
+    // deliberately inside a block statement
+    eval("var y");
+  }
+}
+
+function g1()
+{
+  for (let x = 0; x < 9; ++x)
+  {
+    // deliberately inside a block statement
+    eval("var y");
+  }
+}
+g1();
+
+function g2()
+{
+  {
+    for (let x = 0; x < 9; ++x)
+    {
+      // deliberately inside a block statement
+      eval("var y");
+    }
+  }
+}
+g2();
+
+for (let x = 0; x < 9; ++x) {
+  (function() {
+      eval("var y");
+  })();
+}
+
+{
+  for (let x = 0; x < 9; ++x)
+  {
+    // deliberately inside a block statement
+    (function() {
+        eval("var y");
+    })();
+  }
+}
+
+function h1()
+{
+  for (let x = 0; x < 9; ++x)
+  {
+    // deliberately inside a block statement
+    (function() {
+        eval("var y");
+    })();
+  }
+}
+h1();
+
+function h2()
+{
+  {
+    for (let x = 0; x < 9; ++x)
+    {
+      // deliberately inside a block statement
+      (function() { eval("var y"); })();
+    }
+  }
+}
+h2();
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical-environment/for-loop.js b/js/src/tests/non262/lexical-environment/for-loop.js
new file mode 100644
index 0000000000..60e3799d62
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/for-loop.js
@@ -0,0 +1,121 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = "for-loop.js";
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 985733;
+var summary =
+  "ES6 for-loop semantics for for(;;) loops whose heads contain lexical "
+  "declarations";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+function isError(code, type)
+{
+  try
+  {
+    Function(code);
+    throw new Error("didn't throw");
+  }
+  catch (e)
+  {
+    assertEq(e instanceof type, true,
+             "unexpected error for `" + code + "`: got " + e);
+  }
+}
+
+function isOK(code)
+{
+  Function(code);
+}
+
+isError("for (const x; ; ) ;", SyntaxError);
+isError("for (const x = 5, y; ; ) ;", SyntaxError);
+isError("for (const [z]; ; ) ;", SyntaxError);
+//isError("for (const [z, z]; ; ) ;", SyntaxError);
+//isError("for (const [z, z] = [0, 1]; ; ) ;", SyntaxError);
+
+isOK("for (let x; ; ) ;");
+isOK("for (let x = 5, y; ; ) ;");
+
+// I'm fairly sure this is supposed to work: the negative-lookahead rules in
+// IterationStatement ensure that |for (let| *always* is a loop header starting
+// with a lexical declaration.  But I'm not 100% certain, so these tests might
+// need to be fixed when we implement the negative-lookahead restrictions.
+isOK("for (let [z] = [3]; ; ) ;");
+isError("for (let [z, z]; ; ) ;", SyntaxError); // because missing initializer
+
+isError("for (let [z, z] = [0, 1]; ; ) ;", SyntaxError);
+
+// A for-loop with lexical declarations, with a mixture of bindings that are and
+// aren't aliased.  (The mixture stress-tests any code that incorrectly assumes
+// all bindings are aliased.)
+var funcs = [];
+for (let [i, j, k] = [0, 1, 2]; i < 10; i++)
+  funcs.push(() => i);
+
+assertEq(funcs[0](), 0);
+assertEq(funcs[1](), 1);
+assertEq(funcs[2](), 2);
+assertEq(funcs[3](), 3);
+assertEq(funcs[4](), 4);
+assertEq(funcs[5](), 5);
+assertEq(funcs[6](), 6);
+assertEq(funcs[7](), 7);
+assertEq(funcs[8](), 8);
+assertEq(funcs[9](), 9);
+
+var outer = "OUTER V IGNORE";
+var save;
+for (let outer = (save = function() { return outer; }); ; )
+  break;
+assertEq(save(), save);
+
+var funcs = [];
+function t(i, name, expect)
+{
+  assertEq(funcs[i].name, name);
+  assertEq(funcs[i](), expect);
+}
+
+if (save() !== "OUTER V IGNORE")
+{
+  var v = "OUTER V IGNORE";
+  var i = 0;
+  for (let v = (funcs.push(function init() { return v; }),
+               0);
+      v = (funcs.push(function test() { return v; }),
+           v + 1);
+      v = (funcs.push(function incr() { return v; }),
+           v + 1))
+  {
+    v = (funcs.push(function body() { return v; }),
+         v + 1);
+    i++;
+    if (i >= 3)
+      break;
+  }
+  t(0, "init", 0);
+  t(1, "test", 2);
+  t(2, "body", 2);
+  t(3, "incr", 5);
+  t(4, "test", 5);
+  t(5, "body", 5);
+  t(6, "incr", 8);
+  t(7, "test", 8);
+  t(8, "body", 8);
+  assertEq(funcs.length, 9);
+}
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical-environment/implicit-this-in-with.js b/js/src/tests/non262/lexical-environment/implicit-this-in-with.js
new file mode 100644
index 0000000000..7c112e2447
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/implicit-this-in-with.js
@@ -0,0 +1,18 @@
+// Test that callees that resolve to bindings on the global object or the
+// global lexical environment get an 'undefined' this inside with scopes.
+
+let g = function () { "use strict"; assertEq(this, undefined); }
+function f() { "use strict"; assertEq(this, undefined); }
+
+with ({}) { 
+  // f is resolved on the global object
+  f();
+  // g is resolved on the global lexical environment
+  g();
+}
+
+f();
+g();
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/nondefinable-function-same-script.js b/js/src/tests/non262/lexical-environment/nondefinable-function-same-script.js
new file mode 100644
index 0000000000..5d569fe4a0
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/nondefinable-function-same-script.js
@@ -0,0 +1,24 @@
+// |reftest| skip-if(!xulRuntime.shell)
+
+function assertEvaluateAndIndirectEvalThrows(str) {
+  assertThrowsInstanceOf(() => evaluate(str), TypeError);
+  assertThrowsInstanceOf(() => (1,eval)(str), TypeError);
+}
+
+// Regular vars
+assertEvaluateAndIndirectEvalThrows(`var NaN; function NaN() {}`);
+
+// for-of vars
+assertEvaluateAndIndirectEvalThrows(`for (var NaN of []); function NaN() {}`);
+
+// Annex B.3.3 synthesized vars
+assertEvaluateAndIndirectEvalThrows(`{ function NaN() {} } function NaN() {}`);
+
+// Non-data properties
+Object.defineProperty(this, 'foo', { set: function() {} });
+assertEvaluateAndIndirectEvalThrows(`var foo; function foo() {}`);
+assertEvaluateAndIndirectEvalThrows(`for (var foo of []); function foo() {}`);
+assertEvaluateAndIndirectEvalThrows(`{ function foo() {} } function foo() {}`);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/redeclaring-global-properties.js b/js/src/tests/non262/lexical-environment/redeclaring-global-properties.js
new file mode 100644
index 0000000000..7fb2f82db1
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/redeclaring-global-properties.js
@@ -0,0 +1,64 @@
+// |reftest| skip-if(!xulRuntime.shell) -- needs evaluate
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+// Attempting to lexically redefine a var is a syntax error.
+evaluate("var a;");
+assertThrowsInstanceOf(() => evaluate("let a;"), SyntaxError);
+
+// Attempting to lexically redefine a configurable global property that's not a
+// var is okay.
+this.b = 42;
+assertEq(b, 42);
+evaluate("let b = 17;");
+assertEq(b, 17);
+
+// Attempting to lexically redefine a configurable global property that wasn't
+// a var initially but was later declared as one, isn't okay.
+this.c = 8675309;
+assertEq(c, 8675309);
+evaluate("var c;");
+assertThrowsInstanceOf(() => evaluate("let c;"), SyntaxError);
+
+// Attempting to lexically redefine a var added by eval code isn't okay.
+assertEq(typeof d, "undefined");
+eval("var d = 33;");
+assertEq(d, 33);
+assertThrowsInstanceOf(() => evaluate("let d;"), SyntaxError);
+
+// Attempting to lexically redefine a var added by eval code, then deleted *as a
+// name*, is okay.  (The |var| will add the name to the global environment
+// record's [[VarNames]], but deletion will go through the global environment
+// record's DeleteBinding and so will remove it.)
+assertEq(typeof e, "undefined");
+eval("var e = 'ohia';");
+assertEq(e, "ohia");
+delete e;
+assertEq(this.hasOwnProperty("e"), false);
+evaluate("let e = 3.141592654;");
+assertEq(e, 3.141592654);
+
+// Attempting to lexically redefine a var added by eval code, then deleted *as a
+// property*, isn't okay.  (Deletion by property doesn't go through the global
+// environment record's DeleteBinding algorithm, and so the name isn't removed
+// from [[VarNames]].)  And it remains non-okay even if the var is subsequently
+// deleted as a name, because if the property doesn't exist, it's not removed
+// from [[VarNames]].  But if we add the global property again and then delete
+// by name, it *will* get removed from [[VarNames]].
+assertEq(typeof f, "undefined");
+eval("var f = 8675309;");
+assertEq(f, 8675309);
+delete this.f;
+assertEq(this.hasOwnProperty("f"), false);
+assertThrowsInstanceOf(() => evaluate("let f;"), SyntaxError);
+delete f;
+assertThrowsInstanceOf(() => evaluate("let f;"), SyntaxError);
+this.f = 999;
+assertThrowsInstanceOf(() => evaluate("let f;"), SyntaxError);
+delete f;
+evaluate("let f;");
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical-environment/shell.js b/js/src/tests/non262/lexical-environment/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/shell.js
diff --git a/js/src/tests/non262/lexical-environment/unscopables-basics.js b/js/src/tests/non262/lexical-environment/unscopables-basics.js
new file mode 100644
index 0000000000..4032b27746
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-basics.js
@@ -0,0 +1,22 @@
+// Basics of @@unscopables support.
+
+// In with(obj), if obj[@@unscopables][id] is truthy, then the identifier id
+// is not present as a binding in the with-block's scope.
+var x = "global";
+with ({x: "with", [Symbol.unscopables]: {x: true}})
+    assertEq(x, "global");
+
+// But if obj[@@unscopables][id] is false or not present, there is a binding.
+with ({y: "with", z: "with", [Symbol.unscopables]: {y: false}}) {
+    assertEq(y, "with");
+    assertEq(z, "with");
+}
+
+// ToBoolean(obj[@@unscopables][id]) determines whether there's a binding.
+let someValues = [0, -0, NaN, "", undefined, null, "x", {}, []];
+for (let v of someValues) {
+    with ({x: "with", [Symbol.unscopables]: {x: v}})
+        assertEq(x, v ? "global" : "with");
+}
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-closures.js b/js/src/tests/non262/lexical-environment/unscopables-closures.js
new file mode 100644
index 0000000000..bdade1f113
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-closures.js
@@ -0,0 +1,23 @@
+// @@unscopables continues to work after exiting the relevant `with` block,
+// if the environment is captured by a closure.
+
+let env = {
+    x: 9000,
+    [Symbol.unscopables]: {x: true}
+};
+
+function make_adder(x) {
+    with (env)
+        return function (y) { return x + y; };
+}
+assertEq(make_adder(3)(10), 13);
+
+// Same test, but with a bunch of different parts for bad luck
+let x = 500;
+function make_adder_with_eval() {
+    with (env)
+        return eval('y => eval("x + y")');
+}
+assertEq(make_adder_with_eval()(10), 510);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-const.js b/js/src/tests/non262/lexical-environment/unscopables-const.js
new file mode 100644
index 0000000000..7e1d0e07c6
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-const.js
@@ -0,0 +1,8 @@
+// @@unscopables prevents a property from having any effect on assigning to a
+// const binding (which is an error).
+
+const x = 1;
+with ({x: 1, [Symbol.unscopables]: {x: true}})
+    assertThrowsInstanceOf(() => {x = 2;}, TypeError);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-delete.js b/js/src/tests/non262/lexical-environment/unscopables-delete.js
new file mode 100644
index 0000000000..3cd296f4b9
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-delete.js
@@ -0,0 +1,27 @@
+// If obj[@@unscopables][id], then `delete id` works across `with (obj)` scope.
+
+this.niche = 7;
+let obj = { niche: 8, [Symbol.unscopables]: { niche: true } };
+with (obj) {
+    delete niche;
+}
+
+assertEq(obj.niche, 8);
+assertEq("niche" in this, false);
+
+// Same thing, but delete a variable introduced by sloppy direct eval.
+this.niche = 9;
+function f() {
+    eval("var niche = 10;");
+    with (obj) {
+        assertEq(niche, 10);
+        delete niche;
+    }
+    assertEq(niche, 9);
+}
+
+// Of course none of this affects a qualified delete.
+assertEq(delete this.niche, true);
+assertEq("niche" in this, false);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-getters.js b/js/src/tests/non262/lexical-environment/unscopables-getters.js
new file mode 100644
index 0000000000..1360787983
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-getters.js
@@ -0,0 +1,41 @@
+// @@unscopables checks can call getters.
+
+// The @@unscopables property itself can be a getter.
+let hit1 = 0;
+let x = "global x";
+let env1 = {
+    x: "env1.x",
+    get [Symbol.unscopables]() {
+        hit1++;
+        return {x: true};
+    }
+};
+with (env1)
+    assertEq(x, "global x");
+assertEq(hit1, 1);
+
+// It can throw; the exception is propagated out.
+function Fit() {}
+with ({x: 0, get [Symbol.unscopables]() { throw new Fit; }})
+    assertThrowsInstanceOf(() => x, Fit);
+
+// Individual properties on the @@unscopables object can have getters.
+let hit2 = 0;
+let env2 = {
+    x: "env2.x",
+    [Symbol.unscopables]: {
+        get x() {
+            hit2++;
+            return true;
+        }
+    }
+};
+with (env2)
+    assertEq(x, "global x");
+assertEq(hit2, 1);
+
+// And they can throw.
+with ({x: 0, [Symbol.unscopables]: {get x() { throw new Fit; }}})
+    assertThrowsInstanceOf(() => x, Fit);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-global.js b/js/src/tests/non262/lexical-environment/unscopables-global.js
new file mode 100644
index 0000000000..1aa4a52bda
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-global.js
@@ -0,0 +1,18 @@
+// @@unscopables does not affect the global environment.
+
+this.x = "global property x";
+let y = "global lexical y";
+this[Symbol.unscopables] = {x: true, y: true};
+assertEq(x, "global property x");
+assertEq(y, "global lexical y");
+assertEq(eval("x"), "global property x");
+assertEq(eval("y"), "global lexical y");
+
+// But it does affect `with` statements targeting the global object.
+{
+    let x = "local x";
+    with (this)
+        assertEq(x, "local x");
+}
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-ignored.js b/js/src/tests/non262/lexical-environment/unscopables-ignored.js
new file mode 100644
index 0000000000..08b042a3b5
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-ignored.js
@@ -0,0 +1,22 @@
+// In these cases, @@unscopables should not be consulted.
+
+// Because obj has no properties `assertEq` or `x`,
+// obj[@@unscopables] is not checked here:
+var obj = {
+    get [Symbol.unscopables]() {
+        throw "tried to read @@unscopables";
+    }
+};
+var x = 3;
+with (obj)
+    assertEq(x, 3);
+
+// If @@unscopables is present but not an object, it is ignored:
+for (let nonObject of [undefined, null, "nothing", Symbol.for("moon")]) {
+    let y = 4;
+    let obj2 = {[Symbol.unscopables]: nonObject, y: 5};
+    with (obj2)
+        assertEq(y, 5);
+}
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-miss.js b/js/src/tests/non262/lexical-environment/unscopables-miss.js
new file mode 100644
index 0000000000..b86d510787
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-miss.js
@@ -0,0 +1,7 @@
+// Trying to access a binding that doesn't exist due to @@unscopables
+// is a ReferenceError.
+
+with ({x: 1, [Symbol.unscopables]: {x: true}})
+    assertThrowsInstanceOf(() => x, ReferenceError);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-mutation-frozen.js b/js/src/tests/non262/lexical-environment/unscopables-mutation-frozen.js
new file mode 100644
index 0000000000..632785c05a
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-mutation-frozen.js
@@ -0,0 +1,18 @@
+// When env[@@unscopables].x changes, bindings can appear even if env is inextensible.
+
+let x = "global";
+let unscopables = {x: true};
+let env = Object.create(null);
+env[Symbol.unscopables] = unscopables;
+env.x = "object";
+Object.freeze(env);
+
+for (let i = 0; i < 1004; i++) {
+    if (i === 1000)
+        unscopables.x = false;
+    with (env) {
+        assertEq(x, i < 1000 ? "global" : "object");
+    }
+}
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-mutation.js b/js/src/tests/non262/lexical-environment/unscopables-mutation.js
new file mode 100644
index 0000000000..2f35e1dd3c
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-mutation.js
@@ -0,0 +1,44 @@
+// When obj[@@unscopables].x changes, bindings appear and disappear accordingly.
+
+let x = "global";
+function getX() { return x; }
+
+let unscopables = {x: true};
+let obj = {x: "obj", [Symbol.unscopables]: unscopables};
+
+with (obj) {
+    assertEq(x, "global");
+    x = "global-1";
+    assertEq(x, "global-1");
+    assertEq(obj.x, "obj");
+
+    unscopables.x = false;  // suddenly x appears in the with-environment
+
+    assertEq(x, "obj");
+    x = "obj-1";
+    assertEq(getX(), "global-1");  // unchanged
+    assertEq(obj.x, "obj-1");
+
+    unscopables.x = true;  // *poof*
+
+    assertEq(x, "global-1");
+    x = "global-2";
+    assertEq(getX(), "global-2");
+    assertEq(obj.x, "obj-1");  // unchanged
+
+    // The determination of which binding is assigned happens when the LHS of
+    // assignment is evaluated, before the RHS. This is observable if we make
+    // the binding appear or disappear during evaluation of the RHS, before
+    // assigning.
+    x = (unscopables.x = false, "global-3");
+    assertEq(getX(), "global-3");
+    assertEq(obj.x, "obj-1");
+
+    x = (unscopables.x = true, "obj-2");
+    assertEq(getX(), "global-3");
+    assertEq(obj.x, "obj-2");
+}
+
+assertEq(x, "global-3");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-proto.js b/js/src/tests/non262/lexical-environment/unscopables-proto.js
new file mode 100644
index 0000000000..dbbfb712d3
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-proto.js
@@ -0,0 +1,39 @@
+// @@unscopables treats properties found on prototype chains the same as other
+// properties.
+
+const x = "global x";
+const y = "global y";
+
+// obj[@@unscopables].x works when obj.x is inherited via the prototype chain.
+let proto = {x: "object x", y: "object y"};
+let env = Object.create(proto);
+env[Symbol.unscopables] = {x: true, y: false};
+with (env) {
+    assertEq(x, "global x");
+    assertEq(delete x, false);
+    assertEq(y, "object y");
+}
+assertEq(env.x, "object x");
+
+// @@unscopables works if is inherited via the prototype chain.
+env = {
+    x: "object",
+    [Symbol.unscopables]: {x: true, y: true}
+};
+for (let i = 0; i < 50; i++)
+    env = Object.create(env);
+env.y = 1;
+with (env) {
+    assertEq(x, "global x");
+    assertEq(y, "global y");
+}
+
+// @@unscopables works if the obj[@@unscopables][id] property is inherited.
+env = {
+    x: "object",
+    [Symbol.unscopables]: Object.create({x: true})
+};
+with (env)
+    assertEq(x, "global x");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-proxy.js b/js/src/tests/non262/lexical-environment/unscopables-proxy.js
new file mode 100644
index 0000000000..fcf241ee46
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-proxy.js
@@ -0,0 +1,46 @@
+// Object operations are performed in the right order, as observed by proxies.
+
+let log = [];
+function LoggingProxyHandlerWrapper(name, handler={}) {
+    return new Proxy(handler, {
+        get(t, id) {
+            let method = handler[id];
+            return function (...args) {
+                log.push([name + "." + id, ...args.filter(v => typeof v !== "object")]);
+                if (method === undefined)
+                    return Reflect[id].apply(null, args);
+                return method.apply(this, args);
+            };
+        }
+    });
+}
+
+function LoggingProxy(name, target) {
+    return new Proxy(target, new LoggingProxyHandlerWrapper(name));
+}
+
+let proto = {x: 44};
+let proto_proxy = new LoggingProxy("proto", proto);
+let unscopables = {x: true};
+let unscopables_proxy = new LoggingProxy("unscopables", {x: true});
+let env = Object.create(proto_proxy, {
+    [Symbol.unscopables]: { value: unscopables_proxy }
+});
+let env_proxy = new LoggingProxy("env", env);
+
+let x = 11;
+function f() {
+    with (env_proxy)
+        return x;
+}
+
+assertEq(f(), 11);
+
+assertDeepEq(log, [
+    ["env.has", "x"],
+    ["proto.has", "x"],
+    ["env.get", Symbol.unscopables],
+    ["unscopables.get", "x"]
+]);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-strict.js b/js/src/tests/non262/lexical-environment/unscopables-strict.js
new file mode 100644
index 0000000000..fd0413ed7b
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-strict.js
@@ -0,0 +1,32 @@
+// Strict assignment to the name of a property that's masked by @@unscopables
+// throws a ReferenceError.
+
+let env = {k: 1};
+let f;
+with (env) {
+    f = function () {
+        "use strict";
+        k = 2;
+    };
+}
+
+f();
+assertEq(env.k, 2);
+
+env[Symbol.unscopables] = {k: true};
+assertThrowsInstanceOf(f, ReferenceError);
+
+// @@unscopables is tested when the LHS of assignment is evaluated, so there is
+// no effect on the assignment if it is changed while evaluating the RHS.
+let g;
+with (env) {
+    g = function () {
+        "use strict";
+        k = (env[Symbol.unscopables].k = true, 3);
+    }
+}
+env[Symbol.unscopables].k = false;
+g();
+assertEq(env.k, 3);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/non262/lexical-environment/unscopables-tdz.js b/js/src/tests/non262/lexical-environment/unscopables-tdz.js
new file mode 100644
index 0000000000..ce6b1df929
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/unscopables-tdz.js
@@ -0,0 +1,9 @@
+// Accessing an uninitialized variable due to @@unscopables is still a ReferenceError.
+
+with ({x: 1, [Symbol.unscopables]: {x: true}})
+    assertThrowsInstanceOf(() => x, ReferenceError);
+
+let x;
+
+reportCompare(0, 0);
+
diff --git a/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-destructuring.js b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-destructuring.js
new file mode 100644
index 0000000000..06174013e8
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-destructuring.js
@@ -0,0 +1,10 @@
+// |reftest| skip-if(!xulRuntime.shell)
+
+assertThrowsInstanceOf(() => evaluate(`try { throw {} } catch ({e}) { var e; }`), SyntaxError);
+assertThrowsInstanceOf(() => evaluate(`try { throw {} } catch ({e}) { eval('var e'); }`), SyntaxError);
+
+assertThrowsInstanceOf(() => new Function(`try { throw {} } catch ({e}) { var e; }`), SyntaxError);
+assertThrowsInstanceOf(new Function(`try { throw {} } catch ({e}) { eval('var e'); }`), SyntaxError);
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-for-of.js b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-for-of.js
new file mode 100644
index 0000000000..b433b68b6e
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval-for-of.js
@@ -0,0 +1,12 @@
+// |reftest| skip-if(!xulRuntime.shell)
+
+evaluate(`
+    try { throw null; } catch (e) { eval("for (var e of []) {}") }
+`);
+
+new Function(`
+    try { throw null; } catch (e) { eval("for (var e of []) {}") }
+`)();
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);
diff --git a/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval.js b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval.js
new file mode 100644
index 0000000000..e380846e25
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b-eval.js
@@ -0,0 +1,21 @@
+// Tests annex B.3.5 that introduces a var via direct eval.
+
+var x = "global-x";
+var log = "";
+
+// Tests that direct eval works.
+function g() {
+  try { throw 8; } catch (x) {
+    eval("var x = 42;");
+    log += x;
+  }
+  x = "g";
+  log += x;
+}
+g();
+
+assertEq(x, "global-x");
+assertEq(log, "42g");
+
+if ("reportCompare" in this)
+  reportCompare(true, true)
diff --git a/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b.js b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b.js
new file mode 100644
index 0000000000..6e6a24f213
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/var-in-catch-body-annex-b.js
@@ -0,0 +1,114 @@
+// Tests annex B.3.5.
+
+assertThrowsInstanceOf(function () {
+  eval(`
+       function f() {
+         let x;
+         try {} catch (x) {
+           var x;
+         }
+       }
+       `);
+}, SyntaxError);
+
+assertThrowsInstanceOf(function () {
+  eval(`
+       function f() {
+         try {} catch (x) {
+           let y;
+           var y;
+         }
+       }
+       `);
+}, SyntaxError);
+
+assertThrowsInstanceOf(function () {
+  eval(`
+       function f() {
+         try {} catch (x) {
+           let x;
+         }
+       }
+       `);
+}, SyntaxError);
+
+assertThrowsInstanceOf(function () {
+  eval(`
+       function f() {
+         try {} catch (x) {
+           const x;
+         }
+       }
+       `);
+}, SyntaxError);
+
+// Tests that redeclaring a var inside the catch is not allowed if there's a
+// body-level lexical.
+assertThrowsInstanceOf(function () {
+  eval(`
+    let x;
+    try {} catch (x) {
+      var x;
+    }
+    `);
+}, SyntaxError);
+
+var log = '';
+var x = 'global-x';
+
+function g() {
+  x = 'g';
+  try { throw 8; } catch (x) {
+    var x = 42;
+    log += x;
+  }
+  log += x;
+}
+g();
+
+// Tests that var declaration is allowed in for-in head.
+function h0() {
+  try {} catch (e) {
+    for (var e in {});
+  }
+}
+h0();
+
+// Tests that var declaration is allowed in C-for head.
+function h1() {
+  try {} catch (e) {
+    for (var e;;);
+  }
+}
+h1();
+
+// Tests that var declaration is allowed in for-of head.
+function h2() {
+  try {} catch (e) {
+    for (var e of {});
+  }
+}
+h2();
+
+// Tests that redeclaring a var inside the catch is allowed.
+function h3() {
+  var e;
+  try {} catch (e) {
+    var e;
+  }
+}
+h3();
+
+if (typeof evaluate === "function") {
+  assertThrowsInstanceOf(function () {
+    evaluate(`
+             let y;
+             try {} catch (y) { var y; }
+             `);
+  }, SyntaxError);
+}
+
+assertEq(log, "42g");
+
+if ("reportCompare" in this)
+  reportCompare(true, true)
diff --git a/js/src/tests/non262/lexical-environment/with-global-ignores-global-let-variables.js b/js/src/tests/non262/lexical-environment/with-global-ignores-global-let-variables.js
new file mode 100644
index 0000000000..042f92f688
--- /dev/null
+++ b/js/src/tests/non262/lexical-environment/with-global-ignores-global-let-variables.js
@@ -0,0 +1,18 @@
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+let v = "global-v";
+
+function f(v, global)
+{
+  with (global)
+    return v;
+}
+
+assertEq(f("argument-v", this), "argument-v",
+         "let-var shouldn't appear in global for |with| purposes");
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");
diff --git a/js/src/tests/non262/lexical/browser.js b/js/src/tests/non262/lexical/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical/browser.js
diff --git a/js/src/tests/non262/lexical/regress-336376-01.js b/js/src/tests/non262/lexical/regress-336376-01.js
new file mode 100644
index 0000000000..ef6a0f435d
--- /dev/null
+++ b/js/src/tests/non262/lexical/regress-336376-01.js
@@ -0,0 +1,322 @@
+/* -*- tab-width: 2; indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER     = "336376";
+var summary = "Tests reserved words in contexts in which they are not reserved";
+var actual, expect;
+
+printBugNumber(BUGNUMBER);
+printStatus(summary);
+
+/**************
+ * TEST SETUP *
+ **************/
+
+//
+// New tests go in Tester.prototype._tests.  A test is called with a single
+// argument, the keyword to test in the syntax tested by that test.  Tests
+// should not return anything, and they should signal failure by throwing an
+// explanatory exception and success by not throwing one.
+//
+// If you define a new test, make sure to name it using an informative string
+// for ease of use if any keywords ever manually define the array of tests they
+// should pass, and add it as a string to ALL_TESTS.
+//
+
+// all tests
+const ALL_TESTS =
+  [
+    "CONTEXT_OBJECT_LITERAL_PROPERTY",
+    "CONTEXT_OBJECT_PROPERTY_DOT_REFERENCE",
+    "CONTEXT_OBJECT_PROPERTY_DOT_REFERENCE_IS_FUNCTION",
+    "CONTEXT_OBJECT_PROPERTY_DOT_GET",
+    "CONTEXT_OBJECT_PROPERTY_DOT_SET",
+    ];
+
+function r(keyword, tests)
+{
+  /**
+   * @param keyword
+   *   the keyword as a string
+   * @param tests
+   *   array of test numbers against it, or leave undefined to run all tests
+   *   against it
+   */
+  function Reserved(keyword, tests)
+  {
+    this.keyword = keyword;
+    if (tests)
+      this.tests = tests;
+    else
+      this.tests = ALL_TESTS;
+  }
+  Reserved.prototype =
+    {
+      toString:
+      function()
+      {
+	return "'" + this.keyword + "' being run against tests " +
+	this.tests;
+      }
+    };
+  return new Reserved(keyword, tests);
+}
+
+// ECMA-262, 3rd. ed. keywords -- see 7.5.2
+const ECMA_262_3_KEYWORD =
+  [
+    r("break"),
+    r("case"),
+    r("catch"),
+    r("continue"),
+    r("default"),
+    r("delete"),
+    r("do"),
+    r("else"),
+    r("finally"),
+    r("for"),
+    r("function"),
+    r("if"),
+    r("in"),
+    r("instanceof"),
+    r("new"),
+    r("return"),
+    r("switch"),
+    r("this"),
+    r("throw"),
+    r("try"),
+    r("typeof"),
+    r("var"),
+    r("void"),
+    r("while"),
+    r("with"),
+    ];
+
+// ECMA-262, 3rd. ed. future reserved keywords -- see 7.5.3
+const ECMA_262_3_FUTURERESERVEDKEYWORD =
+  [
+    r("abstract"),
+    r("boolean"),
+    r("byte"),
+    r("char"),
+    r("class"),
+    r("const"),
+    r("debugger"),
+    r("double"),
+    r("enum"),
+    r("export"),
+    r("extends"),
+    r("final"),
+    r("float"),
+    r("goto"),
+    r("implements"),
+    r("import"),
+    r("int"),
+    r("interface"),
+    r("long"),
+    r("native"),
+    r("package"),
+    r("private"),
+    r("protected"),
+    r("public"),
+    r("short"),
+    r("static"),
+    r("super"),
+    r("synchronized"),
+    r("throws"),
+    r("transient"),
+    r("volatile"),
+    ];
+
+// like reserved words, but not quite reserved words
+const PSEUDO_RESERVED =
+  [
+    r("true"),
+    r("false"),
+    r("null"),
+    ];
+
+// new-in-ES4 reserved words -- fill this as each is implemented
+const ECMA_262_4_RESERVED_WORDS =
+  [
+    r("let")
+    ];
+
+
+
+/**
+ * @param keyword
+ *   string containing the tested keyword
+ * @param test
+ *   the number of the failing test
+ * @param error
+ *   the exception thrown when running the test
+ */
+function Failure(keyword, test, error)
+{
+  this.keyword = keyword;
+  this.test = test;
+  this.error = error;
+}
+Failure.prototype =
+{
+  toString:
+  function()
+  {
+    return "*** FAILURE on '" + this.keyword + "'!\n" +
+    "* test:     " + this.test + "\n" +
+    "* error:    " + this.error + "\n";
+  }
+};
+
+function Tester()
+{
+  this._failedTests = [];
+}
+Tester.prototype =
+{
+  testReservedWords:
+  function(reservedArray)
+  {
+    var rv;
+    for (var i = 0, sz = reservedArray.length; i < sz; i++)
+    {
+      var res = reservedArray[i];
+      if (!res)
+	continue;
+
+      var tests = res.tests;
+      for (var j = 0, sz2 = tests.length; j < sz2; j++)
+      {
+	var test = tests[j];
+	if (!test)
+	  continue;
+
+	try
+	{
+	  this._tests[test](res.keyword);
+	}
+	catch (e)
+	{
+	  this._failedTests.push(new Failure(res.keyword, test, e));
+	}
+      }
+    }
+  },
+  flushErrors:
+  function ()
+  {
+    if (this._failedTests.length > 0) {
+      var except = "*************************\n" +
+      "* FAILURES ENCOUNTERED! *\n" +
+      "*************************\n";
+      for (var i = 0, sz = this._failedTests.length; i < sz; i++)
+	except += this._failedTests[i];
+      throw except;
+    }
+  },
+  _tests:
+  {
+    CONTEXT_OBJECT_LITERAL_PROPERTY:
+    function(keyword)
+    {
+      try
+      {
+	eval("var o = { " + keyword + ": 17 };\n" +
+	     "if (o['" + keyword + "'] != 17)\n" +
+	     "throw \"o['" + keyword + "'] == 17\";");
+      }
+      catch (e)
+      {
+	throw e;
+      }
+    },
+    CONTEXT_OBJECT_PROPERTY_DOT_REFERENCE:
+    function(keyword)
+    {
+      try
+      {
+	eval("var o = { \"" + keyword + "\": 17, baz: null };\n" +
+	     "if (o." + keyword + " != 17)\n" +
+	     "throw \"o." + keyword + " == 17\";");
+      }
+      catch (e)
+      {
+	throw e;
+      }
+    },
+    CONTEXT_OBJECT_PROPERTY_DOT_REFERENCE_IS_FUNCTION:
+    function(keyword)
+    {
+      try
+      {
+	eval("var o = { '" + keyword + "': function() { return 17; }, baz: null };\n" +
+	     "if (o." + keyword + "() != 17)\n" +
+	     "throw \"o." + keyword + " == 17\";");
+      }
+      catch (e)
+      {
+	throw e;
+      }
+    },
+    CONTEXT_OBJECT_PROPERTY_DOT_GET:
+    function(keyword)
+    {
+      try
+      {
+	var o = {};
+	eval("o['" + keyword + "'] = 17;\n" +
+	     "if (o." + keyword + " != 17)\n" +
+	     "throw \"'o." + keyword + " != 17' failed!\";");
+      }
+      catch (e)
+      {
+	throw e;
+      }
+    },
+    CONTEXT_OBJECT_PROPERTY_DOT_SET:
+    function(keyword)
+    {
+      try
+      {
+	var o = {};
+	eval("o." + keyword + " = 17;\n" +
+	     "if (o['" + keyword + "'] != 17)\n" +
+	     "throw \"'o." + keyword + " = 17' failed!\";");
+      }
+      catch (e)
+      {
+	throw e;
+      }
+    },
+  }
+};
+
+
+/***************
+ * BEGIN TESTS *
+ ***************/
+
+var failed = false;
+
+try
+{
+  var tester = new Tester();
+  tester.testReservedWords(ECMA_262_3_KEYWORD);
+  tester.testReservedWords(ECMA_262_3_FUTURERESERVEDKEYWORD);
+  tester.testReservedWords(PSEUDO_RESERVED);
+  tester.testReservedWords(ECMA_262_4_RESERVED_WORDS);
+  tester.flushErrors();
+}
+catch (e)
+{
+  failed = e;
+}
+
+expect = false;
+actual = failed;
+
+reportCompare(expect, actual, summary);
diff --git a/js/src/tests/non262/lexical/regress-346642-04.js b/js/src/tests/non262/lexical/regress-346642-04.js
new file mode 100644
index 0000000000..6898864904
--- /dev/null
+++ b/js/src/tests/non262/lexical/regress-346642-04.js
@@ -0,0 +1,33 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 346642;
+var summary = 'decompilation of destructuring assignment';
+var actual = '';
+var expect = '';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+ 
+  expect = 'No Crash';
+  actual = 'No Crash';
+  try
+  {
+    (function() { for (var [a, b] in []) for ([c, d] in []) { } });
+  }
+  catch(ex)
+  {
+    actual = ex + '';
+  }
+  reportCompare(expect, actual, summary);
+}
diff --git a/js/src/tests/non262/lexical/regress-351515.js b/js/src/tests/non262/lexical/regress-351515.js
new file mode 100644
index 0000000000..47690b7455
--- /dev/null
+++ b/js/src/tests/non262/lexical/regress-351515.js
@@ -0,0 +1,94 @@
+/* -*- tab-width: 2; indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 351515;
+var summary = 'Invalid uses of yield, let keywords in js17';
+var actual = '';
+var expect = '';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+try
+{
+  expect = "No Error";
+  eval('yield = 1;');
+  actual = 'No Error';
+}
+catch(ex)
+{
+  actual = ex.name;
+}
+reportCompare(expect, actual, summary + ': global: yield = 1');
+
+try
+{
+  expect = "No Error";
+  eval('(function(){yield = 1;})');
+  actual = 'No Error';
+}
+catch(ex)
+{
+  actual = ex.name;
+}
+reportCompare(expect, actual, summary + ': local: yield = 1');
+
+try
+{
+  expect = "No Error";
+  eval('let = 1;');
+  actual = 'No Error';
+}
+catch(ex)
+{
+  actual = ex.name;
+}
+reportCompare(expect, actual, summary + ': global: let = 1');
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+ 
+  try
+  {
+    expect = "No Error";
+    eval('function f(yield, let) { return yield+let; }');
+    actual = 'No Error';
+  }
+  catch(ex)
+  {
+    actual = ex.name;
+  }
+  reportCompare(expect, actual, summary +
+		': function f(yield, let) { return yield+let; }');
+
+  try
+  {
+    expect = "No Error";
+    eval('var yield = 1;');
+    actual = 'No Error';
+  }
+  catch(ex)
+  {
+    actual = ex.name;
+  }
+  reportCompare(expect, actual, summary + ': function () {var yield;}');
+
+  try
+  {
+    expect = "No Error";
+    eval('var let = 1;');
+    actual = 'No Error';
+  }
+  catch(ex)
+  {
+    actual = ex.name;
+  }
+  reportCompare(expect, actual, summary + ': function () { var let;}');
+}
diff --git a/js/src/tests/non262/lexical/shell.js b/js/src/tests/non262/lexical/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/non262/lexical/shell.js