Re: [xslt] Bug 538580 – wrong xpath matching on text()[ position-number ]

[Daniel Veillard <veillard redhat com>]

  First sorry for the delay, I'm still behind !

On Fri, Jan 30, 2009 at 10:49:35PM -0800, Ron Burk wrote:
> In looking at this bug, I tried just testing the XPath
> behavior directly, and it seemed to do the right thing,
> making me assume that the XSLT code was passing in the
> wrong context positions.
>
> That led me to pattern.c in the libxslt directory.
> In the function xsltTestCompMatch(), it sure enough
> looks like the code does context renumbering for
> XSLT_OP_ELEM and XSLT_OP_ALL, but fails to do so
> for XSLT_OP_TEXT. Thus, in template match patterns
> like "text()[2]", it may produce erroneous results
> when the current selection set contains non-text
> nodes because it passes incorrect position numbers
> to XPath.
>
> I'm happy to take a stab at patching this (by cutting,
> pasting, and tweaking one of the other two highly
> similar position renumbering loops) if someone
> with more experience with the code can a) confirm
> this is the right place for a fix and b) review
> the patch attempt (and (c) tell me what the heck
> the tab settings are supposed to be in this
> code, 'cause I sure can't find any that actually
> make the indentation come out right!). Or,
> if there's something else I can do to help get
> the bug fixed, I'm happy to do that too.
>
> I also don't see any renumbering going on for comments,
> processing instructions, or named processing instructions.
> Would those be bugs as well?

  yes looking at the bug and description it seems libxslt is in
error and the area you spotted is the right place to fix. This
doesn't look urgent, but if you could try to fix his, yes that
would be very welcome :-)

  thanks !

Daniel

-- 
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