Re: [Tclxml-users] Re: Question on -final usage in tclxml-2.4

[Steve B. <Ste...@zv...>]

Mats Bengtsson wrote:
> I checked out a fresh copy of tclxml (version 2.5 released today),
> and found that most (all?) of my changes already were applied
> (by Steve Ball presumably). I've been running my patched tclxml
> daily for a year, with a lot of chopped off xml, and that works fine.
> However, the cvs version does not work as previously noted.
> There are some more changes to the cvs version compared to my version.
> The main difference seems to be in sgmlparser, and after some
> search I found the code:
> 	# Patch from bug report #596959, Marshall Rose
> to be the reason.
> Just do:
> 	if {0} {
> 	# Patch from bug report #596959, Marshall Rose
> 	if {[string compare [lindex $sgml 4] ""]} {
> 	    set sgml [linsert $sgml 0 {} {} {} {} {}]
> 	}
> 	}
> 
> I don't know the reason for this code. This must be sorted out
> by the author. This would never have happened if there were a test
> case with -final 0 and chopped off xml. So, please someone,
> add this so we wont see bugs like this again.

It is quite clear that making this change will break
regression tests.  At this stage we need three things:

1. A test case for bug #596959
2. A test case for bug #413341
3. Make sure that *both* tests pass

According to Marshall's bug report, the Jabber client's
use of TclXML tickled the bug so applying your change
will break that program.

> There remains a question of how to actually use the -final option.
> I use it always when there is a risc of incomplete xml.
> Is there any reason for using -final 1? What's the advantage?

The simpler case when you know that the document is complete.
See also below.

> Test case on mac (I've a special pkgIndex file that sets version to 3.0 in order
> to not interfere with other installations):

Until we release v3.0...

> % package require xml
> 3.0
> (Build) 2 % 
> (Build) 3 % proc cdata {data args} {
> 
>>        puts $data
>>}
> 
> (Build) 4 % 
> (Build) 5 % set parser [::xml::parser parseit \
> 
>>        -characterdatacommand cdata -final 0]
> 
> parseit
> (Build) 6 % 
> (Build) 7 % $parser parse "<the>"
> 
> (Build) 8 % $parser parse "world"
> world
> (Build) 9 % $parser parse "</the>"

Don't you set '-final 1' at all?  Setting that configuration
option to 1 from 0 does a final check that the document
is well-formed.  Consider:

	$parser parse "<the>"
	$parser parse "world"

"<the>world" is not well-formed XML, but you will never
know that because the parsing ends and no error is raised.

Cheers,
Steve Ball

-- 
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