Up to this revision, barcodes set in reports are generated
using the controller `/report/barcode`,
using a `img` HTML tag, e.g. (from `report_location_barcode`)
```
<img t-if="not o.loc_barcode"
t-att-src="'/report/barcode/?type=%s&value=%s&width=%s&height=%s'
% ('Code128', o.name, 600, 100)" style="width:300px;height:50px"/>
``
This `/report/barcode` route is set as `auth='user'`, meaning
the route can only be accessed by signed in users.
When wkhtmltopdf prints a report containing such a barcode,
it calls this `report/barcode` route, making sure to pass
the request session in the cookies, so wkhtmltopdf
uses the same session than the one of the user. This is
needed, as only users can access this `report/barcode/` route.
This session is passed in `report.py`, in the method
`_run_wkhtmltopdf`, thanks to the --cookie wkhtmltopdf
parameter.
Nevertheless, if a report is printed through the website
front-end, as public (without a signed in user), the request
session is not associated to a signed in user, and therefore
the route `/report/barcode` refuses the access / redirects
to the login, making it impossible to print a report
containing a barcode without being signed in. This even
if the report is printed as `sudo` through a controller
(as this is the session of the not signed in user which is passed,
not a session associated to `sudo).
Fixes#10621
opw-667797
Denis Ledoux