xmldb:rename() function fails if the collection name contains spaces

[daliboris]

Collection with spaces in name cannot be renamed

If the collection name contains spaces, calling function xmldb:rename($source-collection-uri as xs:string, $new-collection-name as xs:string) fails with the following error:

exerr:ERROR Could not locate collection: /db/test/data%20with%20spaces [at line 1, column 1, source: String/2077783963999039558]

Expected behavior

Collection with spaces should be renamed.

The xmldb:rename() function with 4 parametrs works if the renamed resource contains spaces, for instance

xmldb:rename('/db/test/', replace('xml with spaces.xml', ' ', '%20'), 'clean-xml.xml')

To Reproduce

xquery version "3.1";

module namespace t="http://exist-db.org/xquery/test";

declare namespace test="http://exist-db.org/xquery/xqsuite";

declare
    %test:setUp
function t:setup() {
    let $testCol := xmldb:create-collection("/db", "test")
    let $spacesCol := xmldb:create-collection("/db/test", "data%20with%20spaces")
    return ()
};

declare
    %test:tearDown
function t:tearDown() {
    xmldb:remove("/db/test")
};

declare
    %test:assertEquals('data%20with%20spaces')
function t:collection-with-spaces-exists() {
    let $result := xmldb:get-child-collections('/db/test/')
    return $result
};

declare
    %test:assertTrue
function t:collection-exists() {
    let $result := xmldb:get-child-collections('/db/test/')
    return
       count($result) eq 1
};

declare
%test:assertError
function t:rename-collection-throws-error() {
    xmldb:rename('/db/test/data%20with%20spaces', '/db/test/data-with-dashes')
};

Context

• Build: eXist-6.2.0 (c8fa4958b6d4a50bd0cba7f3e76a150226414187)
• Java: 1.8.0_332 (Oracle Corporation)
• OS: Linux 5.15.146.1-microsoft-standard-WSL2 (amd64)

[daliboris]

Workaround

• create a new collection
• copy resources from the old collection to the new one
• remove the old collection

let $main-colection := '/db/test'
let $old-collection-name := 'data with spaces'
let $new-collection-name := 'data-with-dashes'

let $old-collection := $main-colection || replace($old-collection-name, ' ', '%20')
let $new-collection := $main-colection || $new-collection-name 

let $resources := xmldb:get-child-resources($old-collection)[matches(., ".*\.*")]
let $created-collection := xmldb:create-collection($main-colection, $new-collection-name)
let $result :=
  for $resource in $resources return
    xmldb:copy-resource($old-collection, $resource, $new-collection, $resource, true())
return (xmldb:remove($old-collection),  $created-collection, $result)

[joewiz]

See discussion at https://github.com/eXist-db/exist/issues/1824. From my summary:

In conclusion, these cases suggest that eXist sometimes silently performs URI-encoding, sometimes doesn't, and may produce identical or different results when you pre-encode a collection name depending on the characters used, and may raise different errors or produce unexpected outcomes if you don't pre-encode. These differences make it difficult to create applications that handle characters consistently, and thus cause users confusion when they encounter inconsistency or errors caused by this design.

[daliboris]

From my point of view, there is an inconsistency in the treatment of collection names.

The following function call works

• xmldb:remove('/db/test/data%20with%20spaces'),

but this one fails

• xmldb:rename('/db/test/data%20with%20spaces', '/db/test/data-with-dashes')

It uses the same (encoded) name of the collection.

[line-o]

@daliboris I tried to reproduce the issue and found it to work with collections with %-encoded spaces:

xquery version "3.1";

let $_ := xmldb:create-collection("/db", "test")
let $_ := xmldb:create-collection("/db/test", "data%20with%20spaces")

return xmldb:rename("/db/test/data%20with%20spaces", "a")

Maybe the issue was just that xmldb:rename expects just the new name of the collection in the second parameter and not the entire path.

[daliboris]

You're right @line-o, your code works.

Maybe the documentation is misleading:

xmldb:rename($source-collection-uri as xs:string, $new-collection-name as xs:string) as item()

Renames the collection $source-collection-uri with new name $new-collection-name.

But the $new-collection-name forms only the last part of the $source-collection-uri.

Or does it mean that the collection name represented by the URI is only the outermost part of the URI, not the entire URI?