Yeah, KI, I asked Vadim about it in 2017, and he said it's not easy to do given the authentication flow we use, but I don't recall why.

Should this be a general auth bug then?

I think I've seen it with other luci web UIs, but never took the time to file it.

Re #1: I don't recall this conversation... Looking now I'd says it is "not trivial", but not exactly very hard. The main problem is that we have no access to URL path in a callback that generates login redirect URLs. But it can be plumbed there in a variety of ways (and Milo already plumbed it in its own special way). I'll write a CL that makes this more generally usable.

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/luci/luci-go.git/+/aa93424fecaf1e07fbe8572cdb83059f16ec6218

commit aa93424fecaf1e07fbe8572cdb83059f16ec6218
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Tue Apr 03 22:11:41 2018

[templates] Plumb request information to DefaultArgs callback.

It is primarily useful for getting the current page's URI to put it in a
login redirect URL to return back to the page after the login. See the included
helloworld_standard example.

R=tandrii@chromium.org, nodir@chromium.org
BUG= 827303 

Change-Id: I0217ab7934669a444b8e10bca50893390cd3861f
Reviewed-on: https://chromium-review.googlesource.com/991194
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/examples/appengine/helloworld_standard/frontend/handler.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/milo/frontend/middleware.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/milo/frontend/routes_test.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/scheduler/appengine/ui/common.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/server/portal/handlers.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/server/templates/bundle.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/server/templates/bundle_test.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/server/templates/context.go
[modify] https://crrev.com/aa93424fecaf1e07fbe8572cdb83059f16ec6218/server/templates/middleware.go

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/luci/luci-go.git/+/5c436e4362845d7bd4a93fa43dff0b760458f42b

commit 5c436e4362845d7bd4a93fa43dff0b760458f42b
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Tue Apr 03 22:25:11 2018

[scheduler] Improve login UX, plus some minor UI fixes.

* Login links now redirect back to the page the user was on before the login.
* Errors are reported via nicer looking HTML page that has login link.
* Suggest login if the project appears to be totally empty.
* Fix breadcrumps markup.
* Add 'text-overflow: ellipsis' for overly long job names.

R=tandrii@chromium.org
BUG= 827303 

Change-Id: I35cabdeae35925eda1bc8e79e5e34d2a130c2633
Reviewed-on: https://chromium-review.googlesource.com/993912
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/includes/base.html
[add] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/error.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/index.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/invocation.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/job.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/project.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/frontend/templates/pages/run_job_result.html
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/ui/common.go
[add] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/ui/errors.go
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/ui/helpers.go
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/ui/invocation.go
[modify] https://crrev.com/5c436e4362845d7bd4a93fa43dff0b760458f42b/scheduler/appengine/ui/job.go

Should work better now.

Thanks!