Re: [xml] xmllint reports non-determinist content model for schema
On Wed, Aug 22, 2012 at 10:40:20PM +0200, Johan Corveleyn wrote: On Fri, Aug 17, 2012 at 10:32 PM, Johan Corveleyn jcor...@gmail.com wrote: On Fri, Feb 24, 2012 at 2:14 PM, Johan Corveleyn jcor...@gmail.com wrote: ... I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. On Tue, Feb 28, 2012 at 6:00 AM, Daniel Veillard veill...@redhat.com wrote: ... Well in that case it seems the underlying code is generating a wrong automata so it should be a matter of running that minimal test case under gdb with the breakpoint appropriately set to find out what wrong transition got added ... I'd like to take a stab at this issue. I've been able to get the latest 2.9.0 snapshot (from ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz) to build in Visual Studio 2010. I can still reproduce the issue. But I need some guidance. What part of the code should I be looking at? Where do I have to set the breakpoint appropriately to find out the wrong transition that got added? Alternatively, if you or anyone else on this list can fix the issue already, that would be even better :-). To summarize, the issue is this: Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint complains with Schemas parser error : local complex type: The content model is not determinist. But it isn't. See also https://bugzilla.gnome.org/show_bug.cgi?id=670865. Hi, I could really use some guidance here. I've been able to set up everything in Visual Studio 2010, and reproduced the issue from within the debugger. So I can set a breakpoint etc. But I mostly lack some basic knowledge about how this all works. Is there some (preferable concise) reading about basic concepts like how xml schemas automata work, how these are built, etc? What should the automata in this case look like (in terms of the data structures inside the code)? How can I see that the automata is non-determinist, and what would a determinist automata look like, ... ? Johan, sorry for the slow answer, I will look at this, promise, but all that code is rooted in automata theory, there is quite some litterature about it, and well unless you go though the process of learning that code and possibly the theory behind it, it's not something that can be hacked trivially. Basically I run this in debug mode, look at the automata generated, there is pro bably an error there and then this need fixing and a lot of checking. To be honnest that one of the hardest part of the library to change with the core of the parser. Theory is usually learnt though the 'Dragon Book', by Aho and Al. and the code is actually more complex since using extended automata operations not found in basic automata ... If you have time looking at this may be interesting, but it's really not trivial at least more complex than other parts of the code :-) Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ dan...@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/ ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org https://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
On Thu, Aug 23, 2012 at 3:03 PM, Daniel Veillard veill...@redhat.com wrote: On Wed, Aug 22, 2012 at 10:40:20PM +0200, Johan Corveleyn wrote: On Fri, Aug 17, 2012 at 10:32 PM, Johan Corveleyn jcor...@gmail.com wrote: On Fri, Feb 24, 2012 at 2:14 PM, Johan Corveleyn jcor...@gmail.com wrote: ... I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. On Tue, Feb 28, 2012 at 6:00 AM, Daniel Veillard veill...@redhat.com wrote: ... Well in that case it seems the underlying code is generating a wrong automata so it should be a matter of running that minimal test case under gdb with the breakpoint appropriately set to find out what wrong transition got added ... I'd like to take a stab at this issue. I've been able to get the latest 2.9.0 snapshot (from ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz) to build in Visual Studio 2010. I can still reproduce the issue. But I need some guidance. What part of the code should I be looking at? Where do I have to set the breakpoint appropriately to find out the wrong transition that got added? Alternatively, if you or anyone else on this list can fix the issue already, that would be even better :-). To summarize, the issue is this: Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint complains with Schemas parser error : local complex type: The content model is not determinist. But it isn't. See also https://bugzilla.gnome.org/show_bug.cgi?id=670865. Hi, I could really use some guidance here. I've been able to set up everything in Visual Studio 2010, and reproduced the issue from within the debugger. So I can set a breakpoint etc. But I mostly lack some basic knowledge about how this all works. Is there some (preferable concise) reading about basic concepts like how xml schemas automata work, how these are built, etc? What should the automata in this case look like (in terms of the data structures inside the code)? How can I see that the automata is non-determinist, and what would a determinist automata look like, ... ? Johan, sorry for the slow answer, I will look at this, promise, but all that code is rooted in automata theory, there is quite some litterature about it, and well unless you go though the process of learning that code and possibly the theory behind it, it's not something that can be hacked trivially. Basically I run this in debug mode, look at the automata generated, there is pro bably an error there and then this need fixing and a lot of checking. To be honnest that one of the hardest part of the library to change with the core of the parser. Theory is usually learnt though the 'Dragon Book', by Aho and Al. and the code is actually more complex since using extended automata operations not found in basic automata ... If you have time looking at this may be interesting, but it's really not trivial at least more complex than other parts of the code :-) Thanks for your answer, and for pointing out that it's not so simple :-). It seems that this is a bit over my head then (I have little clue about automata theory, so it would probably take me weeks or months to understand what's going on ...). I hope you can find some time to dig in further in the not-too-distant future :-). I'm always willing to help out, test, ... if that would be useful (though my usefulness might be limited because of my non-understanding of things ...). Thanks for all your efforts, -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org https://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
On Thu, Aug 23, 2012 at 5:32 PM, Daniel Veillard veill...@redhat.com wrote: On Thu, Aug 23, 2012 at 09:03:44PM +0800, Daniel Veillard wrote: On Wed, Aug 22, 2012 at 10:40:20PM +0200, Johan Corveleyn wrote: [...] Is there some (preferable concise) reading about basic concepts like how xml schemas automata work, how these are built, etc? What should the automata in this case look like (in terms of the data structures inside the code)? How can I see that the automata is non-determinist, and what would a determinist automata look like, ... ? Johan, sorry for the slow answer, I will look at this, promise, but all that code is rooted in automata theory, there is quite some litterature about it, and well unless you go though the process of learning that code and possibly the theory behind it, it's not something that can be hacked trivially. Basically I run this in debug mode, look at the automata generated, there is pro bably an error there and then this need fixing and a lot of checking. To be honnest that one of the hardest part of the library to change with the core of the parser. Theory is usually learnt though the 'Dragon Book', by Aho and Al. and the code is actually more complex since using extended automata operations not found in basic automata ... If you have time looking at this may be interesting, but it's really not trivial at least more complex than other parts of the code :-) Okay simce people may get curious: 1/ I fixed the issue see the tiny patch attached 2/ following is an explanation of what I did to debug the issue in case people may want to fix other issues there of if they are just curious how a developper may spend half an hour of his time :-) Steps: 0/ make minimal xsd and xml the one given were quite good 1/ think about the pattern that is being expressed, it's rule * (specialRule rule *) ? that should be determinist actually so yes that looks like a bug 2/ run xmllint --schema tst.xsd tst.xml clearly libxml2 regexp think it's not determinist, and there is a construction problem as hinted before 3/ edit xmlregexp.c comment off the 4 debugging macros at the top recompile xmllint and run it on the example 4/ start to study the nice output given: --- thinkpad:~/XML - xmllint --schema tst.xsd tst.xml Add trans from 0 to 1 atom: string once 'rule' Add trans from 1 to 1 atom: string once 'rule' Add trans from 0 to 1 epsilon transition Add trans from 1 to 2 atom: string once 'specialRule' Add trans from 2 to 3 atom: string once 'rule' Add trans from 3 to 3 atom: string once 'rule' Add trans from 2 to 3 epsilon transition Add trans from 1 to 3 epsilon transition Found epsilon trans 1 from 2 to 3 xmlFAReduceEpsilonTransitions(2, 3) State 3 is final, so 2 becomes final Add trans from 2 to 3 atom: string once 'rule' Found epsilon trans 2 from 1 to 3 xmlFAReduceEpsilonTransitions(1, 3) State 3 is final, so 1 becomes final Add trans from 1 to 3 atom: string once 'rule' Found epsilon trans 1 from 0 to 1 xmlFAReduceEpsilonTransitions(0, 1) State 1 is final, so 0 becomes final Add trans from 0 to 1 atom: string once 'rule' Add trans from 0 to 2 atom: string once 'specialRule' Add trans from 0 to 3 atom: string once 'rule' xmlFAComputesDeterminism ctxt: '(null)' 5 atoms: 00 atom: string once 'rule' 01 atom: string once 'rule' 02 atom: string once 'specialRule' 03 atom: string once 'rule' 04 atom: string once 'rule' 4 states: start: 0 state: FINAL 0, 5 transitions: trans: atom 0, to 1 trans: removed trans: atom 1, to 1 trans: atom 2, to 2 trans: atom 4, to 3 state: FINAL 1, 4 transitions: trans: atom 1, to 1 trans: atom 2, to 2 trans: removed trans: atom 4, to 3 state: FINAL 2, 3 transitions: trans: atom 3, to 3 trans: removed trans: atom 4, to 3 state: FINAL 3, 1 transitions: trans: atom 4, to 3 0 counters: Final: 4 states Final: 2 atoms Indet: state 0 trans 4, atom 4 to 3 : 0 to 3 previous to is 2 tst.xsd:4: element complexType: Schemas parser error : local complex type: The content model is not determinist. 5/ make the graph of the automata as it is created and then transformed by epsilon rules reductions, c.f. the picture P1020568.JPG attached something is wrong when adding the 3rd epsilon transition from state 1 to state 3, as the indeterminism is created there, suddenly a rule while in state 0 or 1 could be consumed to go to 1 or to 3. 6/ there is a need to separate the state from the end of the sequence from state 3 to avoid the problem 7/ make the patch adding an extra state at end of
Re: [xml] xmllint reports non-determinist content model for schema
On Fri, Aug 24, 2012 at 12:15 AM, Johan Corveleyn jcor...@gmail.com wrote: [...] I'll give your patch a try on my real-world sample (from which the rules example was deduced), just to be sure. And it works perfectly. Thanks again, you made my day :-). -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org https://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
On Fri, Aug 17, 2012 at 10:32 PM, Johan Corveleyn jcor...@gmail.com wrote: On Fri, Feb 24, 2012 at 2:14 PM, Johan Corveleyn jcor...@gmail.com wrote: ... I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. On Tue, Feb 28, 2012 at 6:00 AM, Daniel Veillard veill...@redhat.com wrote: ... Well in that case it seems the underlying code is generating a wrong automata so it should be a matter of running that minimal test case under gdb with the breakpoint appropriately set to find out what wrong transition got added ... I'd like to take a stab at this issue. I've been able to get the latest 2.9.0 snapshot (from ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz) to build in Visual Studio 2010. I can still reproduce the issue. But I need some guidance. What part of the code should I be looking at? Where do I have to set the breakpoint appropriately to find out the wrong transition that got added? Alternatively, if you or anyone else on this list can fix the issue already, that would be even better :-). To summarize, the issue is this: Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint complains with Schemas parser error : local complex type: The content model is not determinist. But it isn't. See also https://bugzilla.gnome.org/show_bug.cgi?id=670865. Hi, I could really use some guidance here. I've been able to set up everything in Visual Studio 2010, and reproduced the issue from within the debugger. So I can set a breakpoint etc. But I mostly lack some basic knowledge about how this all works. Is there some (preferable concise) reading about basic concepts like how xml schemas automata work, how these are built, etc? What should the automata in this case look like (in terms of the data structures inside the code)? How can I see that the automata is non-determinist, and what would a determinist automata look like, ... ? A bit clueless, -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org https://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
On Fri, Feb 24, 2012 at 2:14 PM, Johan Corveleyn jcor...@gmail.com wrote: ... I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. On Tue, Feb 28, 2012 at 6:00 AM, Daniel Veillard veill...@redhat.com wrote: ... Well in that case it seems the underlying code is generating a wrong automata so it should be a matter of running that minimal test case under gdb with the breakpoint appropriately set to find out what wrong transition got added ... I'd like to take a stab at this issue. I've been able to get the latest 2.9.0 snapshot (from ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz) to build in Visual Studio 2010. I can still reproduce the issue. But I need some guidance. What part of the code should I be looking at? Where do I have to set the breakpoint appropriately to find out the wrong transition that got added? Alternatively, if you or anyone else on this list can fix the issue already, that would be even better :-). To summarize, the issue is this: Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint complains with Schemas parser error : local complex type: The content model is not determinist. But it isn't. See also https://bugzilla.gnome.org/show_bug.cgi?id=670865. -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org https://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
Thanks for confirming. That's already a big help :-). Too bad that there is no other way to express this in XML Schema, which works with xmllint. I'll file an issue in the issue tracker, and hopefully someone will find the time to fix this some day. Cheers, -- Johan On Fri, Feb 24, 2012 at 2:58 PM, Pete Cordell petexml...@codalogic.com wrote: FWIW, the schema looks OK to me and neither Visual Studio or the W3C's XSV seem to report an error, so it does look like a libxml2 bug. And I can't think of another way of expressing what you want that isn't truly non-deterministic. HTH a bit! Pete Cordell Codalogic Ltd Interface XML to C++ the easy way using C++ XML data binding to convert XSD schemas to C++ classes. Visit http://codalogic.com/lmx/ or http://www.xml2cpp.com for more info - Original Message - From: Johan Corveleyn jcor...@gmail.com To: xml@gnome.org Sent: Friday, February 24, 2012 1:14 PM Subject: [xml] xmllint reports non-determinist content model for schema Hi, This is my first post to this list. I searched the mailing list archives and bugzilla, but couldn't find the exact issue I'm confronted with (if I missed something, please point me to it). I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint version 20708 complains with Schemas parser error : local complex type: The content model is not determinist. The intention is to express that there can be any number of rule elements, and there can be at most one specialRule (at any position in between, before, or after the rules). So the following xml's are all valid: ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ specialRule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ rule/ /rules But this one isn't (two specialRules): ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ specialRule/ rule/ /rules Is this a bug in libxml2? And whether or not it's a bug: any workarounds? Can I write my schema in another way to make xmllint succeed, and still express the same constraints? -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
I think it's fair to say that Daniel isn't a great fan is XML XSD Schema, so I imagine it won't be fixed too quickly. I think libxml2's support for Relax NG is better. It might be worth seeing if you can do what you want with that. I've never tried it, but by all accounts Trang should be able to give you a start at converting your XSD to Relax NG if your schema is non-trivial. HTH, Pete Cordell Codalogic Ltd Interface XML to C++ the easy way using C++ XML data binding to convert XSD schemas to C++ classes. Visit http://codalogic.com/lmx/ or http://www.xml2cpp.com for more info - Original Message - From: Johan Corveleyn jcor...@gmail.com To: Pete Cordell petexml...@codalogic.com Cc: xml@gnome.org Sent: Monday, February 27, 2012 8:29 AM Subject: Re: [xml] xmllint reports non-determinist content model for schema Thanks for confirming. That's already a big help :-). Too bad that there is no other way to express this in XML Schema, which works with xmllint. I'll file an issue in the issue tracker, and hopefully someone will find the time to fix this some day. Cheers, -- Johan On Fri, Feb 24, 2012 at 2:58 PM, Pete Cordell petexml...@codalogic.com wrote: FWIW, the schema looks OK to me and neither Visual Studio or the W3C's XSV seem to report an error, so it does look like a libxml2 bug. And I can't think of another way of expressing what you want that isn't truly non-deterministic. HTH a bit! Pete Cordell Codalogic Ltd Interface XML to C++ the easy way using C++ XML data binding to convert XSD schemas to C++ classes. Visit http://codalogic.com/lmx/ or http://www.xml2cpp.com for more info - Original Message - From: Johan Corveleyn jcor...@gmail.com To: xml@gnome.org Sent: Friday, February 24, 2012 1:14 PM Subject: [xml] xmllint reports non-determinist content model for schema Hi, This is my first post to this list. I searched the mailing list archives and bugzilla, but couldn't find the exact issue I'm confronted with (if I missed something, please point me to it). I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint version 20708 complains with Schemas parser error : local complex type: The content model is not determinist. The intention is to express that there can be any number of rule elements, and there can be at most one specialRule (at any position in between, before, or after the rules). So the following xml's are all valid: ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ specialRule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ rule/ /rules But this one isn't (two specialRules): ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ specialRule/ rule/ /rules Is this a bug in libxml2? And whether or not it's a bug: any workarounds? Can I write my schema in another way to make xmllint succeed, and still express the same constraints? -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml
Re: [xml] xmllint reports non-determinist content model for schema
FWIW, the schema looks OK to me and neither Visual Studio or the W3C's XSV seem to report an error, so it does look like a libxml2 bug. And I can't think of another way of expressing what you want that isn't truly non-deterministic. HTH a bit! Pete Cordell Codalogic Ltd Interface XML to C++ the easy way using C++ XML data binding to convert XSD schemas to C++ classes. Visit http://codalogic.com/lmx/ or http://www.xml2cpp.com for more info - Original Message - From: Johan Corveleyn jcor...@gmail.com To: xml@gnome.org Sent: Friday, February 24, 2012 1:14 PM Subject: [xml] xmllint reports non-determinist content model for schema Hi, This is my first post to this list. I searched the mailing list archives and bugzilla, but couldn't find the exact issue I'm confronted with (if I missed something, please point me to it). I'm running into a non-determinist error with a schema even though I don't think it's non-determinist (and both XSV and Xerces agree with me; they too have no problem with the schema). I have reduced my test-case to a simple example, see below. Given the following schema: ?xml version=1.0 encoding=UTF-8? xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema; xs:element name=rules xs:complexType xs:sequence xs:element name=rule minOccurs=0 maxOccurs=unbounded/ xs:sequence minOccurs=0 maxOccurs=1 xs:element name=specialRule minOccurs=1 maxOccurs=1/ xs:element name=rule minOccurs=0 maxOccurs=unbounded/ /xs:sequence /xs:sequence /xs:complexType /xs:element /xs:schema xmllint version 20708 complains with Schemas parser error : local complex type: The content model is not determinist. The intention is to express that there can be any number of rule elements, and there can be at most one specialRule (at any position in between, before, or after the rules). So the following xml's are all valid: ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ specialRule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ /rules ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ rule/ /rules ?xml version=1.0 encoding=UTF-8? rules rule/ rule/ rule/ /rules But this one isn't (two specialRules): ?xml version=1.0 encoding=UTF-8? rules specialRule/ rule/ rule/ specialRule/ rule/ /rules Is this a bug in libxml2? And whether or not it's a bug: any workarounds? Can I write my schema in another way to make xmllint succeed, and still express the same constraints? -- Johan ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml ___ xml mailing list, project page http://xmlsoft.org/ xml@gnome.org http://mail.gnome.org/mailman/listinfo/xml
