GitLab Project Import: Attempting to import a GitLab Export throws 404 due to namespace undefined

Summary

Whenever a user attempts to create a new project by importing a GitLab Export, the user gets a 404 because the namespace is undefined.

Steps to reproduce

1. Create new project
2. Choose "From Import"
3. Choose from "GitLab Export".
4. Get 404

Example Project

What is the current bug behavior?

Namespace in URL is always undefined.

What is the expected correct behavior?

Use the namespace ID already in URL. If not present, default to personal namespace.

Relevant logs and/or screenshots

Kibana: https://log.gprd.gitlab.net/goto/1c823d8782c7ab11482cdb36c46fbd22

For some reason I couldn't find an entry in Sentry, but here's a copy of the stack trace and other info from Kibana:

json.correlation_id
01FHTK2NS7NDZ572YY42H8E0A9
	
json.environment
gprd
	
json.exception.backtrace
app/controllers/import/gitlab_projects_controller.rb:10:in `new', ee/lib/gitlab/ip_address_state.rb:10:in `with', ee/app/controllers/ee/application_controller.rb:44:in `set_current_ip_address', app/controllers/application_controller.rb:497:in `set_current_admin', lib/gitlab/session.rb:11:in `with_session', app/controllers/application_controller.rb:488:in `set_session_storage', lib/gitlab/i18n.rb:105:in `with_locale', lib/gitlab/i18n.rb:111:in `with_user_locale', app/controllers/application_controller.rb:482:in `set_locale', app/controllers/application_controller.rb:476:in `set_current_context', ee/lib/omni_auth/strategies/group_saml.rb:41:in `other_phase', lib/gitlab/metrics/elasticsearch_rack_middleware.rb:16:in `call', lib/gitlab/middleware/rails_queue_duration.rb:33:in `call', lib/gitlab/middleware/speedscope.rb:13:in `call', lib/gitlab/request_profiler/middleware.rb:17:in `call', lib/gitlab/database/load_balancing/rack_middleware.rb:23:in `call', lib/gitlab/metrics/rack_middleware.rb:16:in `block in call', lib/gitlab/metrics/web_transaction.rb:21:in `run', lib/gitlab/metrics/rack_middleware.rb:16:in `call', lib/gitlab/jira/middleware.rb:19:in `call', lib/gitlab/middleware/go.rb:20:in `call', lib/gitlab/etag_caching/middleware.rb:21:in `call', lib/gitlab/middleware/multipart.rb:172:in `call', lib/gitlab/middleware/read_only/controller.rb:50:in `call', lib/gitlab/middleware/read_only.rb:18:in `call', lib/gitlab/middleware/same_site_cookies.rb:27:in `call', lib/gitlab/middleware/handle_malformed_strings.rb:21:in `call', lib/gitlab/middleware/basic_health_check.rb:25:in `call', lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in `call', lib/gitlab/middleware/request_context.rb:21:in `call', config/initializers/fix_local_cache_middleware.rb:11:in `call', lib/gitlab/middleware/rack_multipart_tempfile_factory.rb:19:in `call', lib/gitlab/middleware/sidekiq_web_static.rb:20:in `call', lib/gitlab/metrics/requests_rack_middleware.rb:75:in `call', lib/gitlab/middleware/release_env.rb:12:in `call'
	
json.exception.class
ActiveRecord::RecordNotFound
	
json.exception.message
Couldn't find Namespace with 'id'=undefined

From the 404 log entry:

	69d179c4999730b3-ATL
	
json.component
gitlab
	
json.controller
Import::GitlabProjectsController
	
json.correlation_id
01FHTK2NS7NDZ572YY42H8E0A9

json.meta.caller_id
Import::GitlabProjectsController#new
	
json.meta.client_id
user/2454149
	
json.meta.feature_category
importers
	
json.method
GET
	
json.params
{
  "key": "name",
  "value": ""
},
{
  "key": "namespace_id",
  "value": "undefined"
},
{
  "key": "path",
  "value": ""
}
	
json.path
/import/gitlab_project/new
	
json.pid
52

json.status
404	

Output of checks

GitLab.com, GitLab Enterprise Edition 14.4.0-pre 80746ab8

Workaround

Edit the URL by replacing the undefined' with the ID number of the namespace you want to import into: http://gitlab.com/projects/new?namespace_id=12345#import_project`