Filters from the same category dissappear

[raffchen]

Problem

Evidence / Screenshot

If we have more than one filter from the same category on a search like so:

And then we add a filter from a different category using the side menu, then only the one that was added last stays:

Adding the filters by manually editing the URL still works:

Relevant URL(s)

https://openlibrary.org/search?q=fantasy&mode=everything&subject_facet=Fiction&subject_facet=Fiction%2C+fantasy%2C+general&subject_facet=Fantasy

Reproducing the bug

1. Search for a book and apply multiple filters from the same category, or go to https://openlibrary.org/search?q=fantasy&mode=everything&subject_facet=Fiction&subject_facet=Fiction%2C+fantasy%2C+general&subject_facet=Fantasy
2. Using the side menu, add a filter from a different category, such as Language or Author

• Expected behavior: All of the filters from the Subjects category remain, and the new filter is also applied (like in the 3rd screenshot)
• Actual behavior: The new filter is applied, but all but one of the filters from the Subjects category disappear

Context

• Browser (Chrome, Safari, Firefox, etc): Chrome, Firefox
• OS (Windows, Mac, etc): Windows
• Logged in (Y/N): N
• Environment (prod, dev, local): prod

Notes from this Issue's Lead

Proposal & constraints

Related files

Stakeholders

[raffchen]

After doing some digging, it looks like this is because of webpy's storify function. This is used in webpy's input function which we use in changequery.

https://github.com/webpy/webpy/blob/d3649322b85777b291ac2b7b3699fb6fc839e382/web/utils.py#L130-L141

For my example URL from above, this is the result:

[raffchen]

I've linked a draft fix for this that seems to work.