I have heavy problems with equality and lifetime of on-fly created DOM
Nodes. Anyway I also have working prototype.

Integrated:

<--  ContentModel.java new revision: 1.2
<--  DTDGrammar.java new revision: 1.10
<--  DTDParser.java new revision: 1.4
<--  SyntaxElement.java new revision: 1.6
<--  SyntaxNode.java new revision: 1.4
<--  Tag.java new revision: 1.10

*** Issue 19775 has been marked as a duplicate of this issue. ***

*** Issue 19775 has been marked as a duplicate of this issue. ***

Rolling back. I must improve the ContentModel class reliability.

Reintegrated. Added netbeans.xml.completion system property that can
take following values: fast, default or accurate. Fast maps to
original behaviour, default to behaviour with this fix/enhancement and
accurate is reserved for #20762 implementation.

Default content model doesn't offer all appropriate elements.
e.g. in the xhtml <table> element doesn't offer:
<tr>, ...

Sucesfully tested with XHTML tables. 6 new tests added. Comparing to
infinite input/output possibilities...

I tried on Build 200303132350 with Jesse's sample and completion
doesn't work at all.

Yes, I've been having serious problems with completion lately too (dev
mar 11 I think) but forgot to file it. Working on a <MIME-resolver>, I
think I had a <file> with three <ext>s in it followed by a <resolver>,
and when positioning the cursor after the first <ext>, I could not get
any element completion. Or something like that.

Silent code completion is another issue #32042.

I'm using NB 3.5-RC1.  The implementation which was 
intended to solve this issue seems to be very buggy and 
causes the XML code completion to be usless in many cases.

Try for example:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE root [
	<!ELEMENT root (sub1,sub2?,sub3?,sub4?)>
	<!ELEMENT sub1 (#PCDATA)>
	<!ELEMENT sub2 (#PCDATA)>
	<!ELEMENT sub3 (#PCDATA)>
	<!ELEMENT sub4 (#PCDATA)>
]>

<root>
	<sub1>test</sub1>
	<sub3>test3</sub3>
	 <!-- press ctrl-space here -->
</root>

sub3 and sub4 should be allowed here but nothing is 
allowed.  I use the XML editor a lot to write docbook 
documents, but I can't use v3.5 because of this bug.  I 
thus prefer that this fix will be rollbacked until later 
versions, if it isn't too late for v3.5 final.

I'm affraid that for NB 3.5 it's too late.

Meanwhile there is a system property:

  runide -J-Dnetbeans.xml.completion=fast

fast is another name for the old implementation (that offers more
possibilities).

*** Issue 34453 has been marked as a duplicate of this issue. ***

34453 excerpt:

This may be more XML-module related thing.
When either creating or mounting web module
filesystem then there is code-completion support
in its deployment descriptor (web.xml). However
this works only at begining of that file:

<!-- xml declaration and dtd prolog is here -->
<web-app>
    <!-- here is the place where code-completion
works -->
    <session-config>        
        <session-timeout>
            30
        </session-timeout>
    </session-config>

    <!-- here it does not work -->        
</web-app>

Created attachment 10774 [details]
Another sample.

Created attachment 10781 [details]
Project branch patch

Fixed in prj40_prototype branch.

This patch is worth to deliver to users ASAP, it affects all XML
documents following many common DTDs.

It's safe to backport to release35 (and release the patch via NB-AU).
It's covered by unit tests.

Created attachment 10785 [details]
release35 patch (prepared for beta AU deployment)

This looks like a SIMPLEFIX to me, do you agree? Only a couple of
lines of code changed.

Yes indeed. I just have not been aware of the SIMPLEFIX kw.

I have asked aumasters to deploy updated nbm to beta AU.

VERIFIED 

Fixed also in Nevada Patch 1 and in Arrow.