Hello Sergey,

Based on the spec (http://www.w3.org/TR/xpath-functions-30/#func-generate-id) generate-id() uses the context-item if no argument is present. As the context item is the same in each of your calls, it will return the same id.

Using generate-id($b) should be enough to generate distinct ids.

Cheers, Dirk

On 10/07/14 02:56, Sergey Alekhin wrote:

Hello, this seems to be critical bug in [BaseX7.8.2]. The following code

let $a := <element></element>

for $i in (1 to 5)

return copy $b := $a modify (

insert node attribute id { generate-id() } into $b

)

return $b

will return elements with the same IDs, i.e.:

<element id="id31442"/>

<element id="id31442"/>

<element id="id31442"/>

<element id="id31442"/>

<element id="id31442"/>