Attempting to view details of a key held by a worker results in a 404

[krishanbhasin-px]

Describe the issue:
When I'm running my scheduler, I navigate to the info tab, click on a worker and attempt to view information about one of the keys its holding.
Instead of viewing details about the key, I get a 404.

Note that the URL I'm being sent to is wrong; it has a spurious + in it.

http://localhost:8787/info/task/%28%27getitem-fused-assign-c649044b30796c30cb7b26ffb459d668%27%2C+0%29.html (what the worker's page sends me to)

fails, but

http://localhost:8787/info/task/%28%27getitem-fused-assign-c649044b30796c30cb7b26ffb459d668%27%2C0%29.html

is correct (I removed the + at the very end)

Minimal Complete Verifiable Example:

Anything else we need to know?:
Happy to contribute a PR but I'm having a bit of fun finding the relevant code

Environment:

• Dask & Distributed version: 2024.7.1
• Python version: 3.10
• Operating System: Ubuntu
• Install method (conda, pip, source): pip

[krishanbhasin-px]

Relevant code snippet:

distributed/distributed/http/scheduler/info.py

Lines 130 to 137 in 80b3af5

	class Task(RequestHandler):
	@log_errors
	def get(self, task: str) -> None:
	try:
	key = _get_actual_scheduler_key(task, self.server)
	except KeyError:
	self.send_error(404)
	return

[jacobtomlinson]

This might be relevant too

distributed/distributed/dashboard/components/worker.py

Line 69 in 80b3af5

class StateTable(DashboardComponent):

[krishanbhasin-px]

EDIT: wait this is url un-escape, which is the wrong way around

Relevant?

distributed/distributed/http/scheduler/info.py

Lines 100 to 104 in 80b3af5

	def _get_actual_scheduler_key(key: str, scheduler: Scheduler) -> Key:
	key = escape.url_unescape(key, plus=False)
	if key in scheduler.tasks:
	return key # Basic str key

plus=False means it doesn't convert plus's back to spaces?

But this appears to be deliberate from the comments in #8363

Fix edge cases of task keys containing the '+' sign.