It should be possible to bind custom search widget with multi valued field on mono valued metadata

The goal is to search on a mono valued metadata but by selecting multiple criteria for the search, and doing that with a custom search widget not known in Studio.

Using generic search widget, I can select the "in" operator, I can also select the mono valued string field (by entering it manually) and I can give the name of the widget manually even is Studio does not know it.

But at runtime, the widget is reset when the filter is applied, the search is not done (on DAM at least); Here is the warning in the logs:

2013-10-04 15:08:28,953 WARN  [http-bio-127.0.0.1-8080-exec-3] [org.nuxeo.ecm.platform.el.DocumentModelResolver] Property Conversion failed from class java.util.ArrayList to class java.lang.String