Feature Request

Is your feature request related to an issue? Please describe.

When route_prefix_context is used to apply a prefix on various routes, the supplied route_prefix gets stripped to remove any leading/training slashes. Provided that Pyramid handles /prefix/route and prefix/route the same way, it should not strip the leading slash (it is fine to strip the training one to allow addition of more routes after).

This was highlighted a while back in #2143, but not addressed further.

When working with utilities like https://github.com/Cornices/cornice and https://github.com/Cornices/cornice.ext.swagger, it is possible to define a Service that uses the prefix_route to obtain the correct path for the OpenAPI rendering. Because route_prefix_context strips the path, it is not generating the intended path.

Describe the solution you'd like

Modify this line:

- route_prefix = route_prefix.strip('/')
+ route_prefix = route_prefix.rstrip('/')

When using rstrip and with config.route_prefix_context("/ogcapi"), the routes below get rendered correctly.
They behave and respond exactly the same way as if the path were stripped from the leading /.

With the current strip, all leading / are lost, creating inconsistent paths:

Describe alternatives you've considered

Override the pyramind.config.Configurator.route_prefix_context method.
While this works, it is a dirty workaround as I have to duplicate the code to keep all the other self.begin(), etc. calls.

Additional context
This is where the supplied route_prefix is relevant in the package that uses it for eventual OpenAPI generation :
https://github.com/Cornices/cornice/blob/abfcfd9eeefaf281237ba84a3b90ef5ee0698aa9/src/cornice/pyramidhook.py#L169-L183