In preparation for the work on search, we will simplify the search widget by removing some unnecessary config.

Vector has a config flag wgVectorUseSimpleSearch. It's true by default and true on all Wikimedia wikis.
When set to false, it makes no change to Vector.

The flag adds a simpleSearch id to the search form.
This ID is picked up by the core mediawiki.searchSuggest module to add autocomplete search results to Vector.

When the ID is dropped however, the autocomplete still works as mediawiki.searchSuggest looks for #searchInput as well.

Acceptance criteria

• Drop wgVectorUseSimpleSearch from code
• For compatibility with gadgets always output the simpleSearch ID.

QA steps

We'll want to check a few pages on https://en.m.wikipedia.beta.wmflabs.org/wiki/Main_Page
ensuing that search autocomplete is still working:

Notes

Given our pending changes to search we won't need this in modern Vector

QA Results - Beta