Re: [xml] xmlIO enhancements?

[Daniel Veillard <veillard redhat com>]

On Tue, Apr 05, 2005 at 03:49:05PM -0400, Joel Reed wrote:
> On Tue, Apr 05, 2005 at 01:34:32PM -0400, Daniel Veillard wrote:
> > On Tue, Apr 05, 2005 at 01:22:50PM -0400, Joel Reed wrote:
> > > I'm reviewing xmlFileOpen_real and xmlGzfileOpen_real in xmlIO.c and have
> > > two quick questions/possible improvements (i'll fire off a patch if no
> > > dissenters).
> > >
> > > 1) xmlFileOpen_real does a
> > >
> > >   if (!xmlCheckFilename(path)) return(NULL);
> > >
> > > before the fopen(path, "r") call. This quick-out prevents library users
> > > from ever seeing a message in their structure error handler like
> > > "No such file or directory." By deleting this check, we can let fopen call
> > > fail and set errno, then let normal libxml error handling bubble the
> > > error back up to library users. Any reason why not to do this?
> >
> >    the optimistic way might be better yes. Might be faster too, see
> >
> > http://bugzilla.gnome.org/show_bug.cgi?id=168414
>
> ok, did the patch & i think it uncovered a few test case inconsistencies.
> for example in XMLtests, we do:
>
> 1) $(top_builddir)/xmllint test/$$i 2>&1 > result.$$name
> 2) $(top_builddir)/xmllint result.$$name
>
> this fails for test/ent2 which has a line:
>
>   <!ENTITY title PUBLIC "-//MY-TITLE//FR" "title.xml">
>
> it fails because title.xml is in test/ and #2 above produces a 
> "No such file or directory I/O error." because "result.$$name"
> is not in test/
>
> basically, the patch is making visible these errors which silently failed 
> before. 
>
> how should i fix the testcases? would it be acceptable to say 
>
> 1) $(top_builddir)/xmllint test/$$i 2>&1 > test/result.$$name
> 2) $(top_builddir)/xmllint test/result.$$name

  it is more complex than that I'm afraid. It's is a lookup for an external
parsed entity, which is not required . It does show up:

paphio:~/XML -> xmllint test/ent2 > ent2
paphio:~/XML -> xmllint ent2
warning: failed to load external entity "title.xml"
<?xml version="1.0"?>
<!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
<!ENTITY xml "Extensible Markup Language">
<!ENTITY title PUBLIC "-//MY-TITLE//FR" "title.xml">
<!ENTITY image SYSTEM "img.gif" NDATA GIF>
]>
<EXAMPLE>
  &title;
This text is about XML, the &xml; and this is an embedded <IMG src="image"/>
</EXAMPLE>
paphio:~/XML ->

  but as a warning only. Turning it into a (fatal) error and you simply break
the XML spec compatibility of the parser !
  You cannot raise an I/O error as a fatal error all the time. Also if the
file doesn't exist on-disk it may still be present in a catalog, in that
case no warning and no error should be raised.

Daniel

-- 
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veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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