Bug 220142

Summary:	A possible issue about variable redeclaration
Product:	WebKit	Reporter:	Yang Tian <nwu_ty>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED DUPLICATE
Severity:	Normal	CC:	ashvayka, fpizlo, webkit-bug-importer, ysuzuki
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	PC
OS:	Linux

Description Yang Tian 2020-12-24 05:20:53 PST

# Version
d940b47(https://github.com/WebKit/WebKit-http/commit/d940b477848884f63752d25491d9dd0b9d3ccb2d)

# Testcase1:
// Will throw an SyntaxError
function func() {
    if (1) {
        function o() {}
        var o = 1;
    }
}

# Testcase2:
// Will not throw an SyntaxError
if (1) {
    function o() {};
    var o = 1;
}

# Description
In both of the above examples, an variable 'o' declaration error occurred, however Testcase1 throws an exception and Testcase2 doesn't.

I've tried other engines(such as V8, SpiderMonkey), and they all throw SyntaxError, So i suspect it's a bug of jsc.

Please let me know the result whether this is a bug or not. Looking forward to your reply, thanks! 😆

Comment 1 Radar WebKit Bug Importer 2020-12-31 05:21:13 PST

<rdar://problem/72754003>

Comment 2 Yusuke Suzuki 2020-12-31 12:28:26 PST

Thanks, this is dupe of 163209 :)

*** This bug has been marked as a duplicate of bug 163209 ***