Indicate if searching Full Text or not
When performing a Search with Ctrl+F / the magnifying glass icon, it is possible to search by either "Full Text" or "File Name", but there is no visual indicator of which search type is being performed. The only way to see the current search type is to click on the drop-down arrow on the search bar. As a result, it is easy to forget which type is being used, and to think that there are no results matching a search query, when in reality the search type was really just the opposite of the one expected to be in use.
There should be some kind of visual indicator somewhere on the titlebar indicating what the current search type is. One idea is to place an annotation on the search bar for the current search type, like how there are annotations for the search date range & filetype specifications.
Benefits of the solution
This would make it easier to know at-a-glance what is being searched for by a search operation, thereby reducing the risk of accidentally searching for a file name when Full Text searching is on, or for file content when File Name searching is on.
Adding a visual cue for the search type could make the UI more cluttered, wherever it ends up going. It could also be a waste of space for users who don't change the search type often and don't need to care about what the search type is.