NextCursorPage auto-pagination stops on empty pages with a next cursor #890

Summary

NextCursorPage can carry an explicit server-provided next cursor, but both GetNextPage() and the auto-pager currently stop as soon as the current page has an empty data array.

That means an empty first or intermediate page silently terminates iteration even when has_more is true and next points to a later page containing results.

This is observable through public endpoints using NextCursorPage, including Admin.Organization.Groups.ListAutoPaging.

Reproduction

Using a custom HTTP client, return these pages from Admin.Organization.Groups.ListAutoPaging:

GET /organization/groups
{"data":[],"has_more":true,"next":"cursor-1"}

GET /organization/groups?after=cursor-1
{"data":[{"id":"group-1","created_at":1,"group_type":"group","is_scim_managed":false,"name":"one"}],"has_more":false,"next":null}

On current main, auto-pagination yields no groups and makes only the first request.

The same happens for an empty intermediate page:

page 1: data=[group-1], next=cursor-1
page 2: data=[],        next=cursor-2
page 3: data=[group-2], terminal

Current result is only group-1; page 3 is never requested.

Root cause

NextCursorPage.GetNextPage() returns early on len(r.Data) == 0 before consulting HasMore or Next, and NextCursorPageAutoPager.Next() has the same empty-data termination check.

For explicit-next pagination, the continuation token is the pagination authority. An empty result page does not necessarily mean there is no next page.

Expected behavior

NextCursorPage auto-pagination should follow a non-empty next cursor through empty first or intermediate pages. It should still stop normally when has_more is explicitly false or when no next cursor is provided.

Ordinary populated-page behavior should remain unchanged.