Custom Firefox tweaks

Result

After a single click, everything is selected:

After a double-click, a single word is selected:

After a triple-click, everything is selected:

Result

Pressing Ctrl L or F6 selects the URL bar, but does not copy to clipboard (i.e. a subsequent middle-click paste will not paste the URL):

Pressing Ctrl K selects the search bar, but does not copy to clipboard:

If the URL bar is focused in a tab … … and you switch from a different tab … … to the tab which has the focused URL bar, then sometimes the URL bar is selected, but its content is not copied to clipboard:

Typing a URL auto-completes the rest, but the selection is not copied to clipboard:

Result

Pressing ← seeks backward, pressing → seeks forward by the default amount of seconds in the built-in video player (a <video> element):

Pressing ← seeks backward, pressing → seeks forward by the default amount of seconds in the Picture-in-Picture video player:

Result

After typing a query into the search bar … … submitting the search (e.g. by hitting Enter, clicking the arrow icon, one of the suggestions, or a search engine) does not clear the search bar:

Result

When running the script, the script will automatically find all Firefox directories, and add them to the selection. If it finds more than one and the script was run interactively, it’ll ask you which ones you want to tweak; otherwise, it’ll tweak all of them. The effects of these options are shown in a table in the documentation.