incorrect namespace being sent for "info" nrepl resolution of aliased symbols in completion handler

[brdloush]

(Creating issue for this as @PEZ asked on slack channel #babashka-sci-dev)

With following code..

(ns foo)
(require '[clojure.string :as str])
(str/)

.. and cursor positioned just after the / in str/, calva sends incorrect namespaces in :info messages sent to cider-nrepl server when doing code completion via ctrl+space. Instead of passing foo as :ns in the message, it's actually passing clojure.string. This is what server receives when navigating between the offered code-completed functions:

msg: {:op :info, :ns clojure.string, :symbol str/, :id 34, :session 353803b8-23fd-4383-aa5b-1fb7879dd0c4}
msg: {:op :info, :ns clojure.string, :symbol str/blank?, :id 37, :session 353803b8-23fd-4383-aa5b-1fb7879dd0c4}
msg: {:op :info, :ns clojure.string, :symbol str/capitalize, :id 40, :session 353803b8-23fd-4383-aa5b-1fb7879dd0c4}

Instead of "clojure.string", "foo" should be sent in this case.

According to slack conversation in https://clojurians.slack.com/archives/G01J18EUH6H/p1617016471044200,

pez:calva: 1:14 PM
Hmmm, seems we’re on to something. Calva sends info (correctly) on hover. But also this one with a funny ns when I hit ctrl+space.

pez:calva: 1:22 PM
Yes, wrong ns, even though that has so far not mattered b/c I think that the “regular” nrepl server figures that out, like it also doesn’t actually need the ns. It was added recently because babashka wanted it.
I’ll fix it.

pez:calva: 1:34 PM
The ns thing is just a bug that has gone unnoticed until now.
At least I think so. It looks very deliberate when i look at the code. 😃

FYI The plain emacs + cider + company-mode sends message in following format to nrepl server when fetching information about function params on code-completion. (they're actually using "eldoc" but using "info" or "lookup" should be fine (they just have a bit different keys in the response):

msg {:op :eldoc, :ns foo, :sym str/includes?, :session 4d8840fd-31e9-46a4-9a89-637251afcef9, :id 133}
reply: {ns clojure.string, name includes?, eldoc [[s substr]], type function, status #{done}, docstring True if s includes substr.}

msg {:op :eldoc, :ns foo, :sym str/index-of, :session 4d8840fd-31e9-46a4-9a89-637251afcef9, :id 134}
reply: {ns clojure.string, name index-of, eldoc [[s value] [s value from-index]], type function, status #{done}, docstring Return index of value (string or char) in s, optionally searching
  forward from from-index. Return nil if value not found.}