Bug 205785 – String.prototype.replace() incorrectly handles named references on RegExp w/o named groups

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Alexey Shvayka]

Test case:
  "ab".replace(/a/, "$<c>$<d>")

Expected:
  "$<c>$<d>b"

Actual:
  "$<$<d>b"

ECMA262: https://tc39.es/ecma262/#sec-getsubstitution (step 11)
Test262: https://test262.report/browse/built-ins/RegExp/named-groups/string-replace-nocaptures.js

[Alexey Shvayka]

Created attachment 386812 [details]
Patch

[Ross Kirsling]

Comment on attachment 386812 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=386812&action=review

Wow, what an interesting bug.
r=me, but a couple of questions.

> Source/JavaScriptCore/runtime/StringPrototype.cpp:-226
> -                result.append(replacement.substring(i, 2));
> -                offset = i + 2;
> -                advance = 1;

So was this the correct behavior prior to named capture groups? Or is this too associated with https://github.com/tc39/proposal-regexp-named-groups/issues/29?

> Source/JavaScriptCore/runtime/StringPrototype.cpp:-232
> -                // FIXME: https://bugs.webkit.org/show_bug.cgi?id=176434

We should also close the referenced bug, right?

[Alexey Shvayka]

(In reply to Ross Kirsling from comment #2)
> So was this the correct behavior prior to named capture groups? Or is this
> too associated with
> https://github.com/tc39/proposal-regexp-named-groups/issues/29?

No, I believe it wasn't.
For backwards compatibility, named capture groups leave "$<..>" as-is for a RegExp w/o named groups.

This patch isn't associated with https://github.com/tc39/proposal-regexp-named-groups/issues/29:
I've only removed FIXMEs to avoid submitting another patch.

> We should also close the referenced bug, right?

I've just closed https://bugs.webkit.org/show_bug.cgi?id=176434, thank you.

[WebKit Commit Bot]

The commit-queue encountered the following flaky tests while processing attachment 386812 [details]:

transitions/default-timing-function.html bug 138901 (authors: [e-mail] and [e-mail])
The commit-queue is continuing to process your patch.

[WebKit Commit Bot]

Comment on attachment 386812 [details]
Patch

Clearing flags on attachment: 386812

Committed r254088: <https://trac.webkit.org/changeset/254088>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/58355159>

[Alexey Shvayka]

*** Bug 213023 has been marked as a duplicate of this bug. ***