User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

Use any of the default shortcuts for the search bar (Ctrl+K or Ctrl+E on Windows, Cmd+K on Mac).

Actual results:

The cursor jumps to the search bar, where "? " has just been entered. The "Search with..." option is available from the search bar autocomplete. The "? " text can be deleted, in which case "Search with..." goes away.

The "? " doesn't seem to get passed to the search engine. (I tried DuckDuckGo and Google. The characters aren't present in the URL.) Though a manually entered "? " after the pre-filled one does get passed along. Removing the pre-filled "? " and re-typing it also results in the characters being omitted from the search.

Expected results:

The field should begin empty.