Created attachment 72960 [details]
Photo with lots of embedded XMP tags

This test photo, have been tagged by iViewMedia Pro. I put something on every tag field I could find.

1) Check the tags on the original photo with "strings <original photo> | more"
2) Import the photo to f-spot, and tag it as a favorite during import
3) Check the tags on the imported photo with "strings <imported photo> | more"

I get the following two exceptions during import/tagging.

loading exif data
Saved 1628 bytes
System.ArgumentException: Invalid attribute namespace for namespace declaration.
  at System.Xml.XmlAttribute..ctor (System.String prefix, System.String localName, System.String namespaceURI, System.Xml.XmlDocument doc, Boolean atomizedNames, Boolean checkNamespace) [0x00000] 
  at System.Xml.XmlDocument.CreateAttribute (System.String prefix, System.String localName, System.String namespaceURI, Boolean atomizedNames, Boolean checkNamespace) [0x00000] 
  at System.Xml.XmlDocument.CreateAttribute (System.String prefix, System.String localName, System.String namespaceURI) [0x00000] 
  at SemWeb.RdfXmlWriter.SetAttribute (System.Xml.XmlElement element, System.String nsuri, System.String prefix, System.String localname, System.String val) [0x00000] 
  at SemWeb.RdfXmlWriter.Close () [0x00000] 
  at FSpot.Xmp.XmpFile.Save (System.IO.Stream stream) [0x00000] 

...
...

loading exif data
old = "" new = "" heading = "ASCII"
loading exif data
value = 2005:09:02 16:57:11 len = 19
System.Xml.XmlException: Document element did not appear.  Line 1, position 1.
  at System.Xml.XmlTextReader.Read () [0x00000] 
  at Mono.Xml.EntityResolvingXmlReader.Read () [0x00000] 
  at Mono.Xml.DTDValidatingReader.ReadContent () [0x00000] 
  at Mono.Xml.DTDValidatingReader.Read () [0x00000] 
  at Mono.Xml.Schema.XsdValidatingReader.Read () [0x00000] 
  at System.Xml.XmlValidatingReader.Read () [0x00000] 
  at SemWeb.RdfXmlReader+XmlBaseAwareReader.Read () [0x00000] 
  at SemWeb.RdfXmlReader.Select (StatementSink storage) [0x00000] 
  at SemWeb.Store.Import (StatementSource source) [0x00000] 
  at SemWeb.MemoryStore.Import (StatementSource source) [0x00000] 
  at FSpot.Xmp.XmpFile.Load (System.IO.Stream stream) [0x00000] 
_:bnode1689108480 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag> .
_:bnode1689108480 <http://www.w3.org/1999/02/22-rdf-syntax-ns#li> "City String" .

Seems to be related with bug #356242

I suspect this is the new SemWeb getting upset about the empty About="" attributes... We need to fix SemWeb to handle this.

I checked this RDF extract in the W3 validator (http://www.w3.org/RDF/Validator/) and it parsed successfully (after I joined some tags that had a <CR> in it)

Testing the RDF validator (http://rdfabout.com/demo/validator/) with the same RDF extract (removed the first three lines, and the last two lines so I only kept everything between the first <rdf:RDF>) failed.

Validation failed: An empty relative URI was found in the document but could not be converted into an absolute URI because no base URI is known for the document.

============
W3 validator parsed successfully the following extract:
<?xpacket begin="
" id="W5M0MpCehiHzreSzNTczkc9d"?>
<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Public XMP Toolkit Core 4.0">
   <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
      <rdf:Description rdf:about=""
            xmlns:photoshop="http://ns.adobe.com/photoshop/1.0/">
         <photoshop:Urgency>8</photoshop:Urgency>
         <photoshop:Instructions>Instructions String</photoshop:Instructions>
         <photoshop:City>City String</photoshop:City>
         <photoshop:State>State String</photoshop:State>
         <photoshop:Country>Country String</photoshop:Country>
         <photoshop:TransmissionReference>Job Identifier
String</photoshop:TransmissionReference>
         <photoshop:Headline>Headline String</photoshop:Headline>
         <photoshop:Credit>Provider String</photoshop:Credit>
         <photoshop:Source>Source String</photoshop:Source>
         <photoshop:CaptionWriter>Description Writer
String</photoshop:CaptionWriter>
         <photoshop:AuthorsPosition>Creator Job
Title</photoshop:AuthorsPosition>
         <photoshop:SupplementalCategories>
            <rdf:Bag>
               <rdf:li>Categories 1</rdf:li>
               <rdf:li>Categories 2</rdf:li>
               <rdf:li>Categories 3</rdf:li>
            </rdf:Bag>
         </photoshop:SupplementalCategories>
         <photoshop:DateCreated>2006-09-16</photoshop:DateCreated>
         <photoshop:Category>Category String</photoshop:Category>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:dc="http://purl.org/dc/elements/1.1/">
         <dc:creator>
            <rdf:Seq>
               <rdf:li>Creator Name</rdf:li>
            </rdf:Seq>
         </dc:creator>
         <dc:subject>
            <rdf:Bag>
               <rdf:li>Keyword 1</rdf:li>
               <rdf:li>Keyword 2</rdf:li>
               <rdf:li>Keyword 3</rdf:li>
            </rdf:Bag>
         </dc:subject>
         <dc:description>
            <rdf:Alt>
               <rdf:li xml:lang="x-default">AppleMark&#xD;&#xA;</rdf:li>
            </rdf:Alt>
         </dc:description>
         <dc:title>
            <rdf:Alt>
               <rdf:li xml:lang="x-default">Title String</rdf:li>
            </rdf:Alt>
         </dc:title>
         <dc:rights>
            <rdf:Alt>
               <rdf:li xml:lang="x-default">Copyright Notice String</rdf:li>
            </rdf:Alt>
         </dc:rights>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:xapRights="http://ns.adobe.com/xap/1.0/rights/">
         <xapRights:WebStatement>URL.COM.String</xapRights:WebStatement>
         <xapRights:UsageTerms>
            <rdf:Alt>
               <rdf:li xml:lang="x-default">Rights Usage Terms String</rdf:li>
            </rdf:Alt>
         </xapRights:UsageTerms>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:xap="http://ns.adobe.com/xap/1.0/">
         <xap:Rating>4</xap:Rating>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:Iptc4xmpCore="http://iptc.org/std/Iptc4xmpCore/1.0/xmlns/">
         <Iptc4xmpCore:Location>Location String</Iptc4xmpCore:Location>
         <Iptc4xmpCore:CountryCode>US</Iptc4xmpCore:CountryCode>
         <Iptc4xmpCore:IntellectualGenre>Intellectual Genre
String</Iptc4xmpCore:IntellectualGenre>
         <Iptc4xmpCore:CreatorContactInfo rdf:parseType="Resource">
            <Iptc4xmpCore:CiAdrExtadr>Creator Address 1&#xD;&#xA;Creator
Address 1</Iptc4xmpCore:CiAdrExtadr>
            <Iptc4xmpCore:CiAdrCity>Creator City</Iptc4xmpCore:CiAdrCity>
            <Iptc4xmpCore:CiAdrRegion>Creator
State/Province</Iptc4xmpCore:CiAdrRegion>
            <Iptc4xmpCore:CiAdrPcode>Creator Postal
Code</Iptc4xmpCore:CiAdrPcode>
            <Iptc4xmpCore:CiAdrCtry>Creator Country</Iptc4xmpCore:CiAdrCtry>
            <Iptc4xmpCore:CiTelWork>Creator Phone 1&#xD;&#xA;Creator Phone
2</Iptc4xmpCore:CiTelWork>
            <Iptc4xmpCore:CiEmailWork>Creator email@address1&#xD;&#xA;Creator
email@address2</Iptc4xmpCore:CiEmailWork>
            <Iptc4xmpCore:CiUrlWork>Creator web.address.com1&#xD;&#xA;Creator
web.address.com2</Iptc4xmpCore:CiUrlWork>
         </Iptc4xmpCore:CreatorContactInfo>
         <Iptc4xmpCore:SubjectCode>
            <rdf:Bag>
               <rdf:li>12345678</rdf:li>
               <rdf:li>23456789</rdf:li>
               <rdf:li>34567890</rdf:li>
            </rdf:Bag>
         </Iptc4xmpCore:SubjectCode>
         <Iptc4xmpCore:Scene>
            <rdf:Bag>
               <rdf:li>123456</rdf:li>
               <rdf:li>234567</rdf:li>
               <rdf:li>345678</rdf:li>
            </rdf:Bag>
         </Iptc4xmpCore:Scene>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:mediapro="http://ns.iview-multimedia.com/mediapro/1.0/">
         <mediapro:Status>Status String</mediapro:Status>
         <mediapro:Event>Event String</mediapro:Event>
         <mediapro:People>
            <rdf:Bag>
               <rdf:li>People 1</rdf:li>
               <rdf:li>People 2</rdf:li>
               <rdf:li>People 3</rdf:li>
            </rdf:Bag>
         </mediapro:People>
      </rdf:Description>
   </rdf:RDF>
</x:xmpmeta>                         
<?xpacket end="w"?>

===
The RDF parser at SEMWEB failed the above RDF extract (after removing the first three lines (keeping everything between the first <rdf:RDF> pair)
Error message:
Validation failed: An empty relative URI was found in the document but could not  be converted into an absolute URI because no base URI is known for the document.

Posted a message to the semweb's yahoo group.

http://tech.groups.yahoo.com/group/semweb-dotnet/message/114

Confirmed.

I removed the empty >>about=""<< attribute, and semweb validates it fine. 

Got an answer from semweb.
---
The solution is to set the BaseURI property on the RdfXmlReader before
reading in the document --- a URI that will represent the photo itself.
The URI itself doesn't matter, as long as it won't potentially clash
with other resources that might be found in the RDF.
---

Been trying to modify 
MetadataStore.cs - row 204
	RdfXmlReader rxr = new RdfXmlReader(stream);
	// Set a default BaseUri
	rxr.BaseUri = "dummyforunknowndocs";
	descriptions.Import (rxr);

XmpFile.cs - row 33
	RdfXmlReader rxr = new SemWeb.RdfXmlReader(stream);
	// Set a default BaseUri
	rxr.BaseUri = "dummyforunknowndocs";
	store.Import (rxr);

XmpFile.cs - row 52
        writer = new RdfXmlWriter(rdfdoc);
        // Set a default BaseUri
	writer.BaseUri = "dummyforunknowndocs";


No luck.

I added a debug message, and got the following extra information:
prefix=>rdf<, localname=>nodeID<, nsuri=>http://www.w3.org/1999/02/22-rdf-syntax-ns#<
prefix=>rdf<, localname=>nodeID<, nsuri=>http://www.w3.org/1999/02/22-rdf-syntax-ns#<
prefix=>xmlns<, localname=>CiAdrExtadr<, nsuri=>http://iptc.org/std/Iptc4xmpCore/1.0/xmlns/<
System.ArgumentException: Invalid attribute namespace for namespace declaration.
  at System.Xml.XmlAttribute..ctor (System.String prefix, System.String localName, System.String namespaceURI, System.Xml.XmlDocument doc, Boolean atomizedNames, Boolean checkNamespace) [0x00000] 
  at System.Xml.XmlDocument.CreateAttribute (System.String prefix, System.String localName, System.String namespaceURI, Boolean atomizedNames, Boolean checkNamespace) [0x00000] 
  at System.Xml.XmlDocument.CreateAttribute (System.String prefix, System.String localName, System.String namespaceURI) [0x00000] 
  at SemWeb.RdfXmlWriter.SetAttribute (System.Xml.XmlElement element, System.String nsuri, System.String prefix, System.String localname, System.String val) [0x00000] 
  at SemWeb.RdfXmlWriter.Close () [0x00000] 
  at FSpot.Xmp.XmpFile.Save (System.IO.Stream stream) [0x00000] 

Another answer from semweb (Joshua Tauberer)
==========

> I tried to set the BaseUri just before the Import was done.
> But I still get the following error.
> 
> System.ArgumentException: Invalid attribute namespace for namespace
> declaration.

That's a real bug.  It was caused by the library trying to make up a
namespace prefix, and it came up with a bad one: "xmlns", which is of
course reserved for XML namespaces.

I'm pushing version 0.75 to the website in a few minutes
(http://razor.occams.info/code/semweb) which fixes this, plus a number
of other things that have been waiting to be released for a few months.

==========
Have not tried this latest release of their semweb though.

ok, well I just commited a hack to work around that in our code as well.  The code in cvs should work properly at least.