From f294aa213c8313c8ab6d42da022ef26f6a39705d Mon Sep 17 00:00:00 2001
From: Adam Vandolder <avandolder@mozilla.com>
Date: Wed, 10 Jun 2020 13:40:13 +0000
Subject: [PATCH] Bug 1644581 - Remove Iterator.prototype[@@toStringTag].
 r=jorendorff

Differential Revision: https://phabricator.services.mozilla.com/D78983
---
 js/src/tests/jstests.list                   |  1 -
 js/src/tests/non262/Iterator/proto.js       |  3 +++
 js/src/tests/non262/Iterator/toStringTag.js | 12 ------------
 js/src/vm/Iteration.cpp                     |  7 +------
 4 files changed, 4 insertions(+), 19 deletions(-)
 delete mode 100644 js/src/tests/non262/Iterator/toStringTag.js

diff --git a/js/src/tests/jstests.list b/js/src/tests/jstests.list
index b1031cc92d46..8ffdb6804f25 100644
--- a/js/src/tests/jstests.list
+++ b/js/src/tests/jstests.list
@@ -746,7 +746,6 @@ shell-option(--enable-iterator-helpers) script non262/Iterator/constructor.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/constructor-subclassable.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/constructor-throw-when-called-directly.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/constructor-throw-without-new.js
-shell-option(--enable-iterator-helpers) script non262/Iterator/toStringTag.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/from/call-from-with-different-this.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/from/Iterator.from-descriptor.js
 shell-option(--enable-iterator-helpers) script non262/Iterator/from/Iterator.from-length.js
diff --git a/js/src/tests/non262/Iterator/proto.js b/js/src/tests/non262/Iterator/proto.js
index 5b32f5d34b7f..2ab92641e7d3 100644
--- a/js/src/tests/non262/Iterator/proto.js
+++ b/js/src/tests/non262/Iterator/proto.js
@@ -10,5 +10,8 @@ assertEq(propDesc.writable, false);
 assertEq(propDesc.enumerable, false);
 assertEq(propDesc.configurable, false);
 
+// Make sure @@toStringTag hasn't been set.
+assertEq(Symbol.toStringTag in propDesc.value, false);
+
 if (typeof reportCompare === 'function')
   reportCompare(0, 0);
diff --git a/js/src/tests/non262/Iterator/toStringTag.js b/js/src/tests/non262/Iterator/toStringTag.js
deleted file mode 100644
index 91557dcb084e..000000000000
--- a/js/src/tests/non262/Iterator/toStringTag.js
+++ /dev/null
@@ -1,12 +0,0 @@
-// |reftest| skip-if(!this.hasOwnProperty('Iterator')) -- Iterator is not enabled unconditionally
-const propDesc = Reflect.getOwnPropertyDescriptor(Iterator.prototype, Symbol.toStringTag);
-assertEq(propDesc.value, 'Iterator');
-assertEq(propDesc.writable, false);
-assertEq(propDesc.enumerable, false);
-assertEq(propDesc.configurable, true);
-
-class TestIterator extends Iterator {}
-assertEq(new TestIterator().toString(), '[object Iterator]');
-
-if (typeof reportCompare == 'function')
-  reportCompare(0, 0);
diff --git a/js/src/vm/Iteration.cpp b/js/src/vm/Iteration.cpp
index 3bd4bbb66b7b..124d1ae886d4 100644
--- a/js/src/vm/Iteration.cpp
+++ b/js/src/vm/Iteration.cpp
@@ -1523,11 +1523,6 @@ static const JSFunctionSpec iterator_methods_with_helpers[] = {
     JS_SELF_HOSTED_SYM_FN(iterator, "IteratorIdentity", 0, 0),
     JS_FS_END};
 
-static const JSPropertySpec iterator_properties[] = {
-    JS_STRING_SYM_PS(toStringTag, js_Iterator_str, JSPROP_READONLY),
-    JS_PS_END,
-};
-
 /* static */
 bool GlobalObject::initIteratorProto(JSContext* cx,
                                      Handle<GlobalObject*> global) {
@@ -1666,7 +1661,7 @@ static const ClassSpec IteratorObjectClassSpec = {
     iterator_static_methods,
     nullptr,
     iterator_methods_with_helpers,
-    iterator_properties,
+    nullptr,
     nullptr,
 };