xmllint failing on ccmm_sample due to wrong schemaLocation

[roman-dvorak]

Dobrý den,

When trying to validate the provided CCMM sample XML file against the CCMM schema using xmllint:

xmllint --noout --schema dataset/schema.xsd ccmm_sample.xml

Ends with this errors:

error : Unknown IO error
warning: failed to load external entity "http://www.w3.org/XML/1998/namespace"
language-system/schema.xsd:3: element import: Schemas parser warning : Element '{http://www.w3.org/2001/XMLSchema}import': Failed to locate a schema at location 'http://www.w3.org/XML/1998/namespace'. Skipping the import.
...

The issue is that XSD files import the XML namespace like this:

<xs:import namespace="http://www.w3.org/XML/1998/namespace"
           schemaLocation="http://www.w3.org/XML/1998/namespace"/>

SchemaLocation assumes that there is link to XSD file. The correct schema file ('schemaLocitain' atribut) is http://www.w3.org/2001/xml.xsd.

How to solve this issue manually

Replace all occurrences of

schemaLocation="http://www.w3.org/XML/1998/namespace"

with

schemaLocation="http://www.w3.org/2001/xml.xsd"

This can be replaced manually with sed command with:

grep -rl --include='*.xsd' 'schemaLocation="http://www.w3.org/XML/1998/namespace"' . \
| xargs sed -i.bak \
  's|schemaLocation="http://www.w3.org/XML/1998/namespace"|schemaLocation="http://www.w3.org/2001/xml.xsd"|g'

After this fix, the validation is succeessful:

xmllint --noout --schema dataset/schema.xsd ccmm_sample.xml
ccmm_sample.xml validates

---

I would like to add some instructions to the README or Wiki, how we can validate our own schema using the xmllint tool.

_I hope this hasn’t already been solved or discussed somewhere else, I can't find it.

[MichalMed]

Problem is there is n real XML file containing XML definitions. According to W3C, it shall look like this:

<xs:import namespace="http://www.w3.org/XML/1998/namespace"
           schemaLocation="http://www.w3.org/2001/xml.xsd"/>

However, this structure is generated from dataspecer tool. I'm creating issue there.