XQuery: Module imports are not transitive

[ChristianGruen]

The following function should raise an error:

(: b.xqm :)
module namespace b  = 'b';
import module namespace c  = 'c'   at 'c.xqm';

(: c.xqm :)
module namespace c  = 'c';
declare function c:hello(){
  "can you see me now"
};

(: main.xq :)
import module namespace b  = 'b'   at 'b.xqm';
declare namespace c='c';
c:hello()

Original message: https://www.mail-archive.com/basex-talk@mailman.uni-konstanz.de/msg13873.html

[apb2006]

Example from https://www.mail-archive.com/basex-talk@mailman.uni-konstanz.de/msg14507.html

In this case it appears an error, [XQST0049] Duplicate declaration of static variable, is raised by BaseX 9.7 when it should not be.

(: main.xq  :)
import module namespace u = "u" at 'u.xqm'; 
import module namespace c = "c" at 'data/c.xqm';
$u:path

(: u.xqm :)
module  namespace u="u";
declare variable $u:path:="somewhere";

(: data/c.xqm :)
module  namespace c="c";
import module namespace u = "u" at 'u.xqm'; (: cf '../u.xqm' :)
declare function c:foo(){
  "foo"
};

(: data/u.xqm:)
module  namespace u="u";
declare variable $u:path:="somewhere";

Saxon does not raise an error
java -cp "%SAXON_HOME%/saxon9he-9.1.5.jar" net.sf.saxon.Query main.xq

issue.2048.zip