Re: [xml] XPath - crashing using xmlXPathCompiledEval (problem within xmlXPathCtxtCompile?) - long

[Daniel Veillard <veillard redhat com>]

On Mon, Nov 19, 2007 at 02:15:37PM +1100, Andrew Nelson wrote:
> Dear List,
> I am using the latest version of libxml2  (2.6.30) to provide XML  
> support for a program called IGOR Pro on Win32 + MacOSX.  This  
> project takes the form of a C plugin.

 Replying to this very old mail...

> -I compiled the libxml2 source myself.
> -My test XML file is:
> _______________________
> <?xml version="1.0"?>
> <XMLutils/>
> _______________________
>
> -the code fragment I have in my plugin is listed below.  When we get  
> to this stage doc is a valid xmlDocPtr, and xpathExpr = BAD_CAST ("/ 
> XMLutils")
> _____________________________________________________
[...]
> If I run this fragment on the console it works fine.  However, it  
> crashes everytime in my plugin. The stacktrace is
>
> 0   libxml2.2.dylib                   0x17ba9561 xmlPatternMaxDepth +  
> 111 (pattern.c:2545)
> 1   libxml2.2.dylib                   0x17b0d261 xmlXPathRunStreamEval  
> + 69 (xpath.c:14043)
> 2   libxml2.2.dylib                   0x17b0d823 xmlXPathRunEval + 296  
> (xpath.c:14295)
> 3   libxml2.2.dylib                   0x17b0e281  
> xmlXPathCompiledEvalInternal + 233 (xpath.c:14681)
> 4   libxml2.2.dylib                   0x17b0e3d2 xmlXPathCompiledEval +  
> 46 (xpath.c:14745)
> 5   com.apple.carbonbundletemplate    0x179e5186  
> execute_xpath_expression(_xmlDoc*, unsigned char*, unsigned char*,  
> int*) + 180 (XMLevaluateXPathExpression.cpp:126)
>
> I investigated the cause of the crash and it appears that in  
> xmlPatternMaxDepth(pattern.c:2545) the pointer comp->stream is  

  Are you sure when running in your plugin environment you are not
linking to a *different* libxml2 shared library with different options
compiled in ? This sounds the most probable source of the problem.

Daniel

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