Fix bug causing Bitbucket importer to crash when OAuth application had been removed.

CHANGELOG

@@ -16,6 +16,7 @@ v 7.14.0 (unreleased)
   - Expire Rails cache entries after two weeks to prevent endless Redis growth
   - Add support for destroying project milestones (Stan Hu)
   - Add fetch command to the MR page
+  - Fix bug causing Bitbucket importer to crash when OAuth application had been removed.
 
 v 7.13.1
   - Fix: Label modifications are not reflected in existing notes and in the issue list

app/controllers/import/bitbucket_controller.rb

@@ -3,6 +3,7 @@ class Import::BitbucketController < Import::BaseController
   before_action :bitbucket_auth, except: :callback
 
   rescue_from OAuth::Error, with: :bitbucket_unauthorized
+  rescue_from Gitlab::BitbucketImport::Client::Unauthorized, with: :bitbucket_unauthorized
 
   def callback
     request_token = session.delete(:oauth_request_token)

lib/gitlab/bitbucket_import/client.rb

 module Gitlab
   module BitbucketImport
     class Client
+      class Unauthorized < StandardError; end
+
       attr_reader :consumer, :api
 
       def initialize(access_token = nil, access_token_secret = nil)
@@ -46,23 +48,23 @@ module Gitlab
       end
 
       def user
-        JSON.parse(api.get("/api/1.0/user").body)
+        JSON.parse(get("/api/1.0/user").body)
       end
 
       def issues(project_identifier)
-        JSON.parse(api.get("/api/1.0/repositories/#{project_identifier}/issues").body)
+        JSON.parse(get("/api/1.0/repositories/#{project_identifier}/issues").body)
       end
 
       def issue_comments(project_identifier, issue_id)
-        JSON.parse(api.get("/api/1.0/repositories/#{project_identifier}/issues/#{issue_id}/comments").body)
+        JSON.parse(get("/api/1.0/repositories/#{project_identifier}/issues/#{issue_id}/comments").body)
       end
 
       def project(project_identifier)
-        JSON.parse(api.get("/api/1.0/repositories/#{project_identifier}").body)
+        JSON.parse(get("/api/1.0/repositories/#{project_identifier}").body)
       end
 
       def find_deploy_key(project_identifier, key)
-        JSON.parse(api.get("/api/1.0/repositories/#{project_identifier}/deploy-keys").body).find do |deploy_key|
+        JSON.parse(get("/api/1.0/repositories/#{project_identifier}/deploy-keys").body).find do |deploy_key|
           deploy_key["key"].chomp == key.chomp
         end
       end
@@ -82,11 +84,18 @@ module Gitlab
       end
 
       def projects
-        JSON.parse(api.get("/api/1.0/user/repositories").body).select { |repo| repo["scm"] == "git" }
+        JSON.parse(get("/api/1.0/user/repositories").body).select { |repo| repo["scm"] == "git" }
       end
 
       private
 
+      def get(url)
+        response = api.get(url)
+        raise Unauthorized if (400..499).include?(response.code.to_i)
+
+        response
+      end
+
       def config
         Gitlab.config.omniauth.providers.find { |provider| provider.name == "bitbucket"}
       end