Summary:
Fixes T12058. When the user visits `/maniphest`, for example, we redirect to `/maniphest/`.
Since this redirect is very low-level (at the Aphront level, below the Site level) we need to preserve the request Host rather than correct it to `PhabricatorEnv::getURI()` or similar -- the request may be hiting a different Site like a blog domain.
Currently, we do not preserve the port. Instead, preserve the port if it is not a standard port for the protocol (80 for http, 443 for https).
Test Plan:
- Made a request with a missing slash and a normal port in my browser, got redirected normally.
- Made a request with a missing slash and a nonstandard port, got redirected on the same port.
```
$ curl -H 'Host: local.phacility.com:123' -v http://local.phacility.com/diffusion
* Trying 127.0.0.1...
* Connected to local.phacility.com (127.0.0.1) port 80 (#0)
> GET /diffusion HTTP/1.1
...
>
< HTTP/1.1 302 Found
...
< Location: http://local.phacility.com:123/diffusion/
...
```
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T12058
Differential Revision: https://secure.phabricator.com/D17134
c07ec8fee6