[xml] Possible improvement for xmlCleanupParser

[Marc Liyanage <mliyanage futurelab ch>]

Hi there,

Would it be possible to include calls to xmlCleanupInputCallbacks() and 
xmlCleanupOutputCallbacks() in xmlCleanupParser()?
That way, a user of the library who needs to reset everything would 
only have to make one cleanup call, not three.
Is there a reason for not making the two additional calls?


A friend here at work just debugged a hard to find problem with Apache 
2 and the corresponding mod_perl and the XML::LibXML Perl module.
It was in the scheme match/open/close/read callback code / table.

mod_perl loads the module code and the libxml library gets initialized, 
including some perl-specific match/open/close/read callback pointers to 
code in the scheme handler table.
Then for some reason mod_perl unloads the perl module (XS) code again 
and reloads it at a different location. The old pointers in the libxml 
tables are not cleared out by a call to xmlCleanupParser(), and the new 
(valid) ones which are registered a second time get added to the top of 
the table.
Now, when some code tries to access a resource with e.g. file://, the 
code works its way down the stack to the corresponding (default) entry 
in that table, but it crashes before getting there because of the (now 
invalid) code pointers into the already unloaded module in the middle 
of the stack.





-Marc


_________________________________________________________________
Marc Liyanage                                        futureLAB AG

                                         phone:  +41 52 260 22 10
mliyanage futurelab ch                   fax:    +41 52 260 22 23
http://www.futurelab.ch                  mobile: +41 76 554 22 10
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