Bug 6639

Summary:

for/in returns duplicate keys when key exists on object and its prototype

Product:

WebKit

Reporter:

Jesse Costello-Good <jesse>

Component:

JavaScriptCore

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

ap, ian, maksim, mrowe, tolmasky

Priority:

Keywords:

HasReduction

Version:

420+

Hardware:

Mac

OS:

OS X 10.4

Bug Depends on:

Bug Blocks:

10489

Attachments:

Description	Flags
Test case packged suitable for a layout test	none
Further simplified test case	none

Jesse Costello-Good

Reported 2006-01-17 20:52:55 PST

The following code evaluates to "toString toString", however, for...in should never return duplicate keys. var A = function() {}; A.prototype.toString = function() { "A" }; var B = function() {}; B.prototype = new A(); B.prototype.toString = function() { "B" }; var s = ""; for (var f in B.prototype) s += f + " "; s

Attachments
Test case packged suitable for a layout test (1.08 KB, text/html) 2006-01-17 21:56 PST, Mark Rowe (bdash)	no flags	Details
Further simplified test case (931 bytes, text/html) 2006-03-08 02:51 PST, Mark Rowe (bdash)	no flags	Details
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Jesse Costello-Good

Comment 1 2006-01-17 20:53:15 PST

I am evaluating Safari for a port of TIBCO(R) General Interface, a mature AJAX platform that is currently IE only. Fixing this bug would make the port more feasible.

Mark Rowe (bdash)

Comment 2 2006-01-17 21:56:42 PST

Created attachment 5754 [details] Test case packged suitable for a layout test

Mark Rowe (bdash)

Comment 3 2006-01-17 21:58:26 PST

Thanks for the bug report. I can confirm this fails in both WebKit 417.9 and ToT WebKit.

Maciej Stachowiak

Comment 4 2006-02-20 06:42:51 PST

I had a possible fix for this at one point but it caused an apparent performance regression. Maybe time to retest.

Mark Rowe (bdash)

Comment 5 2006-03-08 02:51:22 PST

Created attachment 6937 [details] Further simplified test case

Mark Rowe (bdash)

Comment 6 2006-03-08 02:52:03 PST

*** Bug 7658 has been marked as a duplicate of this bug. ***

Alexey Proskuryakov

Comment 7 2006-07-16 21:44:23 PDT

*** This bug has been marked as a duplicate of 9950 ***

Jesse Costello-Good

Comment 8 2006-11-18 17:22:33 PST

Thanks to the Safari team for being so responsive regarding requests for better advanced AJAX support. Safari is quickly becoming a 1st class AJAX platform.

Jesse Costello-Good

Comment 9 2007-09-04 14:42:32 PDT

This is fixed in Safari 3 for iPhone 1.0.2

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