Search page fails when search is started from a concept page with a ?uri URL parameter

[osma]

URL address of the page where you encountered the problem

https://test.dev.finto.fi/yso/fi/page?uri=http%3A%2F%2Fwww.yso.fi%2Fonto%2Fyso%2Fp19378

Description of the problem

1. Go to a concept page with a URL that includes the uri parameter, e.g. https://test.dev.finto.fi/yso/fi/page?uri=http%3A%2F%2Fwww.yso.fi%2Fonto%2Fyso%2Fp19378 (you can get there for example from the search autocomplete list)
2. Enter a search term, e.g. "koira", and press enter
3. You will be redirected to the URL https://test.dev.finto.fi/yso/fi/page?uri=http%3A%2F%2Fwww.yso.fi%2Fonto%2Fyso/fi/search?clang=fi&q=koira which is nonsensical and doesn't work

The expected outcome would be to show the search result page, e.g. http://localhost/Skosmos/yso/fi/search?clang=fi&q=koira

I think the search box constructs the URL for the search page in a way that doesn't work when the uri parameter is used.

Additional information (e.g. screenshots) about the problem

The browser you used when the problem appeared

Firefox