Bug 5888 – WebKit ignores external (SYSTEM) entity definitions

• Status: RESOLVED
• Resolution: WONTFIX
• Component: DOM

[Eric Seidel (no email)]

WebKit ignores external (SYSTEM) entity definitions

This was done intentionally to prevent blocking the UI while loading a page, since libxml require 
synchronous loading.

This breaks all of the W3C SVG DOM test suite however.  And so far I've found no easy way to work around 
it.

[Eric Seidel (no email)]

I have a patch, I'll post with test cases this evening.

[Eric Seidel (no email)]

I've broken the xslt support part off into:
http://bugzilla.opendarwin.org/show_bug.cgi?id=7184

I'm not sure we'll actually ever want to support external DTD loading for normal xml/xhtml/svg.  The only use case I've seen so far is the SVG dom test suite from curt arnold.

[Alexey Proskuryakov]

*** Bug 8987 has been marked as a duplicate of this bug. ***

[Brett Zamir]

I really hope that you can support external DTDs. It is a useful part of XML and at least modular XHTML. Even if synchronous, given that the entities represent a part of the document, I think it is reasonable.

In any case, per the XML spec, missing entity definitions for an entity reference (unless no DTD is referenced, it is solely an internal document subset with no parameter entities, it is standalone=yes, or you are using a validating parser and the entity reference is not defined) should not be well-formed (single point of failure) errors.

What you can do to address the problem is:
1) Replace the entities
2) Provide a visual indication of the entity's presence and retrieve it for
display on demand
3) Or at the very least, it would seem permissible per the spec (since it doesn't specify exactly how it must be done), to just
indicate the entity's presence (Opera does this by indicating the entity in
source as though it had been manually indicated as an escaped ampersand +
entity text)

See http://www.w3.org/TR/REC-xml/#wf-entdeclared and http://www.w3.org/TR/REC-xml/#include-if-valid

For the record, even NASA was asking Mozilla to fix this bug in their browser ( https://bugzilla.mozilla.org/show_bug.cgi?id=204102 ) and another bug related to loading external DTDs (at https://bugzilla.mozilla.org/show_bug.cgi?id=22942 ) has 78 votes.

Thank you...

[Eric Seidel (no email)]

I'm closing this wontfix.  I don't think we want this.

[Brett Zamir]

Per section 4.4.3 of the XML specification, and per my earlier comment, 

"If a non-validating processor does not include the replacement text, it MUST inform the application that it recognized, but did not read, the entity....Browsers, for example, when encountering an external parsed entity reference, might choose to provide a visual indication of the entity's presence and retrieve it for display only on demand."

If you don't want to support entities, fine, but it is not saying to give a single point of failure (unless standalone=yes per http://www.w3.org/TR/REC-xml/#wf-entdeclared ).

[Lucas Forschler]

Mass moving XML DOM bugs to the "DOM" Component.