FIX: unsuspend a moderator (#35452)

If, for some reasons, you were to try to "unsuspend" a moderator, you
wouldn't be able to because the "can_suspend" was checking for
"user.regular?".

Added a "can_unsuspend?" to support this use-case.

Ref - https://meta.discourse.org/t/-/385786

app/controllers/admin/users_controller.rb

@@ -146,10 +146,12 @@ class Admin::UsersController < Admin::StaffController
   end
 
   def unsuspend
-    guardian.ensure_can_suspend!(@user)
+    guardian.ensure_can_unsuspend!(@user)
+
     @user.suspended_till = nil
     @user.suspended_at = nil
     @user.save!
+
     StaffActionLogger.new(current_user).log_user_unsuspend(@user)
 
     DiscourseEvent.trigger(:user_unsuspended, user: @user)

lib/guardian.rb

@@ -342,10 +342,14 @@ class Guardian
   end
 
   def can_suspend?(user)
-    user && is_staff? && user.regular?
+    can_unsuspend?(user) && user.regular?
   end
   alias can_deactivate? can_suspend?
 
+  def can_unsuspend?(user)
+    user && is_staff?
+  end
+
   def can_revoke_admin?(admin)
     can_administer_user?(admin) && admin.admin?
   end

spec/requests/admin/users_controller_spec.rb

@@ -648,6 +648,23 @@ RSpec.describe Admin::UsersController do
           expect(job_args["payload"]).to eq(WebHook.generate_payload(:user, user))
         end
       end
+
+      it "can unsuspend a user who was granted moderation while suspended" do
+        user.update!(suspended_at: DateTime.now, suspended_till: 2.years.from_now)
+        user.grant_moderation!
+
+        expect(user.reload).to be_suspended
+        expect(user).to be_moderator
+
+        put "/admin/users/#{user.id}/unsuspend.json"
+
+        expect(response.status).to eq(200)
+        user.reload
+        expect(user.suspended_till).to eq(nil)
+        expect(user.suspended_at).to eq(nil)
+        expect(user).not_to be_suspended
+        expect(user).to be_moderator
+      end
     end
   end