[libxml++] Multiple documents with one DomParser

[John Chronakis <linux vmpsoft com>]

Hello,

In my project I am parsing a number of xml documents, each one validated 
against a different inline dtd.
I using only one parser and I am not freeing anything between calls to 
parse_memory().
My program crashes when exiting at the destructor of DomParser (see the 
backtrace),
which means I am doing something wrong.

--- The backtrace of the core dump is the following 
----------------------------------------------------
#0  0x40cb5af4 in mallopt () from /lib/tls/libc.so.6
#1  0x40cb4a4b in free () from /lib/tls/libc.so.6
#2  0x407e694c in xmlRegFreeRegexp () from /usr/lib/libxml2.so.2
#3  0x407a2c78 in xmlSnprintfElementContent () from /usr/lib/libxml2.so.2
#4  0x40797b40 in xmlHashFree () from /usr/lib/libxml2.so.2
#5  0x407a30c9 in xmlFreeElementTable () from /usr/lib/libxml2.so.2
#6  0x407903fe in xmlFreeDtd () from /usr/lib/libxml2.so.2
#7  0x407905d7 in xmlFreeDoc () from /usr/lib/libxml2.so.2
#8  0x40746c13 in xmlpp::Document::~Document () from 
/usr/lib/libxml++-2.6.so.1
#9  0x4074bdbb in xmlpp::DomParser::release_underlying () from 
/usr/lib/libxml++-2.6.so.1
#10 0x4074ae40 in xmlpp::DomParser::~DomParser () from 
/usr/lib/libxml++-2.6.so.1
#11 0x080dfc81 in ~EnvLoader (this=0xbfffe5f4) at ldrScene.h:24
#12 0x08082313 in ~EnvDynSimulation (this=0xbfffdff0) at 
EnvDynSimulation.cpp:24
#13 0x08103d00 in main (argc=6, argv=0xbffffb54) at eds.cpp:28
--------------------------------------------------------------------------------------------------------

Can I use one parser to parse all of them or do I need one parser per 
document?
If one parser is enough, do I need to free any resources between parses?

System is: debian sarge (2.6.8-1-k7), libxml++2.6 (2.6.1-2)

Thanx
John Chronakis




PS: Here is the code I use and a few words, if they help

I want dtds hardcoded, and I couldnt find a method to force DomParser to 
use dtd from a char buffer.
So, I am loading the (plain ascii) xml file into a char buffer, then 
adding the dtd inline (<doctype... [dtdcontent]>)
and calling the parser like this:

...
try
{
       //mp_parser: pointer to my DomParser
       //docstring: the document with the inline dtd
       mp_parser->set_validate();
       mp_parser->set_substitute_entities();

       // Parse the document
       mp_parser->parse_memory(docstring);
      
       if(*mp_parser)
       {
               const xmlpp::Node* pNode = 
mp_parser->get_document()->get_root_node();
               this->parse(pNode);
               // this has a method parse that does the real parsing
               // delete mp_parser->get_document() !!!Crashes!!!
      }
}
...

I call this sniplet a number of times, and I do not free anything 
between calls.
When I tried to delete the document, it crashed.
Everything works fine for the lifetime of my program, but when I finaly 
exit from it, I get a segfault.