287554 - Unicode BOM (byte-order mark) incorrectly displayed on top of page

Status: VERIFIED WORKSFORME

(Firefox :: General, defect)

Description

[Max Timchenko]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0

The summary says it all, actually. See example URL.

Same behavior on the following systems:

Mozilla 1.4.3
Mozilla/5.0 (X11; U; IRIX64 IP30; en-US; rv:1.4.3) Gecko/20040909

Firefox 1.0
MOzilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.5) Gecko/20041107
Firefox/1.0

Mozilla 1.7.1
Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7) Gecko/20040616

Reproducible: Always

Steps to Reproduce:
Visit the example URL. 

Actual Results:  
Unicode BOM (displayed as ) is shown on the page.

Expected Results:  
The BOM should not be displayed.

Comment 1

[Max Timchenko]

On second thought, probably the problem is on my end -- Firefox doesn't
recognize the document as UTF-8 although it is specified in <meta>, when
encoding is changed manually the BOM disappears.

Maybe Apache serves conflicting document encoding? Anyway this is not a Mozilla
bug, marking as WORKSFORME.

Comment 2

[PikeUK]

(In reply to comment #1)
> Maybe Apache serves conflicting document encoding?

Yes it looks like it, the server is sending:

Content-Type: text/html; charset=ISO-8859-1

Which overrules the meta.

Comment 3

[Leif Halvard Silli]

For the time being, the server for that page does not send out any HTTP header that includes encoding information. Hence, Firefox relies 100% on the UTF-8 Byte order mark.

(In reply to comment #1)
For the encoding, then the BOM should take have higher priority than the HTTP header. See:
http://malform.no/testing/html5/bom/
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12897
http://www.w3.org/TR/xml/#sec-guessing-with-ext-info

Therefore, you were originally correct when you complained: the BOM should not be displayed!