Gallery component emits more canvases than user has selected

[irv]

UV version:

 [email protected] (also HEAD)

I'm submitting a:

• [x] bug report
• [ ] feature request => please use the user stories repo
• [ ] support request => Please do not submit support requests here, use stackoverflow

Current behavior:

when selecting some canvases which appear in more than one range, extra canvases are emitted in the event from the gallery component

Expected behavior:

only the selected canvases are emitted Steps to reproduce:

http://access.bl.uk/item/viewer/ark:/81055/vdc_100025703033.0x000001

Select "some or all pages" to download. select pages 2-4 and 10-12 only. check console and see that the event emitted appears to include 54 canvases(!)

Related code:

// insert any relevant code here

Other information: