191139 - unescape %80 using UTF-8 halts javascript execution

Status: RESOLVED DUPLICATE of bug 44272

(Core :: DOM: Core & HTML, defect)

Description

[Frankie]

Years ago I wrote a javascript page to display the first 256 characters. It runs
successfully on Netscape 4 and MSIE (Mac and Windows), as well as Safari, iCab,
and Opera. Mozilla, however, dies on the first table row with the following
javascript console message:

Error: uncaught exception: [Exception... "Component returned failure code:
0x8000ffff (NS_ERROR_UNEXPECTED) [nsIDOMWindowInternal.unescape]"  nsresult:
"0x8000ffff (NS_ERROR_UNEXPECTED)"  location: "JS frame ::
http://jhunix.hcf.jhu.edu/~fuy/character-lister.html :: tablerow :: line 27" 
data: no]

Further testing reveals that any attempt to unescape('%80') will halt the
running javascript.

Comment 1

[Frankie]

Attachment: unescape 80 testcase

Comment 2

[Ruslan Ismailov]

Work for me on Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b)
Gecko/20030127 under WinXP.

Comment 3

[Frankie]

Aha, I found the problem. I set default charset to UTF-8. If I switch to Latin 1
it works as expected.

What's wrong with Unicode character 0x80?

Comment 4

[Phil Schwartau]

The DOM [un]escape() functions supersede the JS Engine versions
in the browser. Reassigning to DOM Level 0.

Note that escape(), unescape() were earlier functions in the language
and are now deprecated. They appear only in the Appendix to ECMA-262
Edition 3. Instead, use encodeURI(), decodeURI().

Reference:
http://devedge.netscape.com/library/manuals/2000/javascript/1.5/guide/fcns.html,
where it states:

----
The escape and unescape functions let you encode and decode strings.
The escape function returns the hexadecimal encoding of an argument
in the ISO Latin character set. The unescape function returns the
ASCII string for the specified hexadecimal encoding value. 

The syntax of these functions is:

                         escape(string)
                       unescape(string) 

These functions are used primarily with server-side JavaScript to encode
and decode name/value pairs in URLs. 

The escape and unescape functions do not work properly for non-ASCII
characters and have been deprecated. In JavaScript 1.5 and later, use

   encodeURI, decodeURI, encodeURIComponent, and decodeURIComponent. 
----



I think that's why we get this DOM error on unescape('%80') when the
browser's charset is set to UTF-8. 

Compare bug 44272, 
"javascript escape and unescape don't work properly with unicode chars"


I think the present bug is either invalid, or a duplicate of that one -

Comment 5

[Frankie]

Thanks for the explanation, Phil.

This will remind me to put a meta content-type tag in all of my pages
(especially ones that try to play games with non-ASCII characters).


*** This bug has been marked as a duplicate of 44272 ***