MAX_URI_LENGTH exceeded results in nonsensical error

Webrick version 1.7.0

When MAX_URI_LENGTH of 2083 is exceeded, instead of failing with the expected HTTPStatus::RequestURITooLarge it instead fails with:

ERROR TypeError: can't convert nil into an exact number
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/activesupport-5.2.8.1/lib/active_support/core_ext/time/calculations.rb:275:in `-'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/activesupport-5.2.8.1/lib/active_support/core_ext/time/calculations.rb:275:in `minus_with_duration'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/activesupport-5.2.8.1/lib/active_support/core_ext/time/calculations.rb:286:in `minus_with_coercion'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/webrick-1.7.0/lib/webrick/accesslog.rb:112:in `setup_params'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/webrick-1.7.0/lib/webrick/httpserver.rb:223:in `access_log'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/webrick-1.7.0/lib/webrick/httpserver.rb:115:in `ensure in run'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/webrick-1.7.0/lib/webrick/httpserver.rb:115:in `run'
	/Users/matthewhively/.rvm/gems/ruby-2.5.7/gems/webrick-1.7.0/lib/webrick/server.rb:310:in `block in start_thread'

httpserver.rb#run() catches the error, but then as part of the ensure block it throws another error.

So the actual issue I suppose is that the ensure block shouldn't be failing, even with some other error condition.

And an additional question:
Why is the MAX_URI_LENGTH remain at a value from 2010 for internet explorer? https://github.com/ruby/webrick/commit/bd7388dd8e68ba68e74eb0e6f42fcf2753e94deb

Start at lib/webrick/httpserver.rb#run and follow its ensure path into access_log, then inspect lib/webrick/accesslog.rb#setup_params. Reproduce a request exceeding MAX_URI_LENGTH and verify that the expected HTTPStatus::RequestURITooLarge is preserved without a secondary TypeError from logging.