XSLT3 test case on-empty-115b constructs a namespace node in which the namespace name comprises a single space character. The spec offers no clear guidance on whether this is allowed or not. Section 2.6 of XDM sits on the fence:
Namespace names, whatever form they take, are treated as character strings and compared for equality using codepoint-by-codepoint comparison, subject only to whitespace normalization if they appear in a context (for example, within an attribute value) where this is appropriate.
It is highly unlikely that namespace names containing spaces will work; there are certainly many places where they won't work.
A namespace name consisting entirely of spaces is particularly problematic, because it is not always clear whether it should be treated as a declaration or an undeclaration.
We currently say:
In this and related specifications, the use of the type xs:anyURI to hold a namespace name does not imply any restrictions on the value space beyond those described in this section: implementations may reject character strings that are not valid URIs or IRIs, but they are not required to do so.
and I would like to see this extended to say:
XSD 1.1 Part 2 states that the use of spaces in xs:anyURIs is strongly discouraged. This applies particularly to URIs used as namespace names. It is therefore RECOMMENDED that character strings containing spaces should not be accepted as namespace names.
XSLT3 test case on-empty-115b constructs a namespace node in which the namespace name comprises a single space character. The spec offers no clear guidance on whether this is allowed or not. Section 2.6 of XDM sits on the fence:
It is highly unlikely that namespace names containing spaces will work; there are certainly many places where they won't work.
A namespace name consisting entirely of spaces is particularly problematic, because it is not always clear whether it should be treated as a declaration or an undeclaration.
We currently say:
and I would like to see this extended to say:
XSD 1.1 Part 2 states that the use of spaces in xs:anyURIs is strongly discouraged. This applies particularly to URIs used as namespace names. It is therefore RECOMMENDED that character strings containing spaces should not be accepted as namespace names.