110734 - Report 404 [file not found] for XSLT document

Status: VERIFIED FIXED

(Core :: XSLT, defect)

Description

[Alex Vincent [:WeirdAl]]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.5+) Gecko/20011116
BuildID:    Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.5+) Gecko/20011116

Loading an XHTML document saved as .xml, I have a missing XSLT document
referenced by a <?xml-stylesheet ?> processing instruction.  This 404 means the
XML parser should ignore the processing instruction; it does not.

Reproducible: Always
Steps to Reproduce:
1. Load the attached testcase (coming up)

Actual Results:  Blank page.

Expected Results:  "If you can read this, you don't need glasses" appears on the
page in H1 format.

Mozilla 0.9.5 renders the page without the special H1 formatting.  So this is
definitely a regression on an already bad bug.

Comment 1

[Alex Vincent [:WeirdAl]]

Attachment: Testcase

Comment 2

[Alex Vincent [:WeirdAl]]

Strange... my local copy of said testcase is coming up blank, but the online
page is giving me plaintext.  :(

Comment 3

[Axel Hecht]

Neither http://www.w3.org/TR/xml-stylesheet/ nor http://www.w3.org/TR/xslt 
specify the behaviour for a 404 in a stylesheet. It's an error, and it should
be reported. A "just do as if nothing ever happened" is plain wrong, IMHO.

Comment 4

[Bradley Baetz (:bbaetz)]

bz touched this in the last couple of days, at least for css

Comment 5

[Peter Van der Beken [:peterv]]

CSS stylesheet loading and XSLT stylesheet loading is totally different afaik. I
doubt it is related.

Comment 6

[Axel Hecht]

*** Bug 144396 has been marked as a duplicate of this bug. ***

Comment 7

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Peter should look at this.

Comment 8

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Btw, in the case of CSS we just act as if there was no stylesheet so one could
argue the same should happen with XSLT. On the other hand, it is very likely
that the data would be totally unusable or seriously wrong, so an error result
is also justified. I think I'd prefer seeing an error message. What does IE do?

Comment 9

[Tim Danner]

IE6 displays this error message when a referenced xslt stylesheet can't be loaded:

The XML page cannot be displayed 
Cannot view XML input using style sheet. Please correct the error and then click
the Refresh button, or try again later. 
--------------------------------------------------------------------------------
XML document must have a top level element. Error processing resource '<url>'. 

In my opinion, an error message like this is the correct behavior. However, when
using IE in this manner, I wish it had a link/button/something to display the
xml without the stylesheet (perhaps in the spiffy IE xml-pretty printing mode).

Comment 10

[Alex Vincent [:WeirdAl]]

IE's behavior is wrong in that they totally deny access to the XML document
underneath.  They block access to the data.

Heikki:  why would it be "totally unusable or seriously wrong"?  MathML and
XHTML are two XML languages Mozilla currently renders (relatively) correctly
without XSLT stylesheets; if the stylesheet is 404 or the wrong mimetype
(there's been another bug filed for that, which this may be a dupe of), an error
is justified, but that doesn't mean the MathML or XHTML aren't any good because
the stylesheet's busted...

For the record, the Amaya 6.1 editor does give the wrong stylesheet PI, which
breaks MathML in Mozilla.  Other than that, the MathML Amaya puts out is on very
solid ground.  (I filed a bug on this, and duped it to that other bug.)

Comment 11

[Heikki Toivonen (remove -bugzilla when emailing directly)]

For example, if I send you a P3P policy file in XML, you will have a hard time
reading it without a stylesheet. An XSLT stylesheet can order the data in
logical order, make summaries, indices, links, and generate content to explain
the terse markup. I think this would be a typical situation where XSLT is used:
the raw XML is useless to most people, and needs some kind of stylesheet to make
any sense for humans.

Also it is quite possible that the raw XML would contain information for several
mutually excusive situations, needing a stylesheet to show and hide the relevant
parts. Without a stylesheet you could easily draw wrong conclusions.

Comment 12

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

*** Bug 181571 has been marked as a duplicate of this bug. ***

Comment 13

[Alex Vincent [:WeirdAl]]

Re comment 2:  Behavior seems to have changed.  In a recent nightly,
Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4a) Gecko/20030328

I get a blank gray screen.

I'm going to e-mail the W3C lists for xml-stylesheet and XSLT.  We really should
get an answer on this.

Comment 14

[Alex Vincent [:WeirdAl]]

http://lists.w3.org/Archives/Public/xsl-editors/2003JanMar/0040.html

Comment 15

[Alex Vincent [:WeirdAl]]

:( W3C hasn't said much yet; the one reply I got says
"implementation-dependent".  We're on our own.

Comment 16

[Axel Hecht]

This should be done with a nsIStreamListener, either directly in txStylesheetSink
or in a separate object. This needs to hook itself up between the channel and
the parser.
This should detect all netwerk errors, including 404 and bad mime.
It could provide a hook for both chrome and file schemes to trigger content
sniffing, too. This would be in OnStartRequest, check for unknown-content and
the right scheme, get the stream-converter-service and convert it. But that
should be a separate bug, IMHO.

Comment 17

[Boris Zbarsky [:bzbarsky]]

> It could provide a hook for both chrome and file schemes to trigger content
> sniffing, too.

That should arguably be moved down into the channel impls, a la ftp and http
channels.

Comment 18

[Peter Van der Beken [:peterv]]

Fixed with checkin for bug 203192.

Comment 19

[Axel Hecht]

mass verifying