Fix applying labels for GitHub-imported MRs

CHANGELOG.md

@@ -26,6 +26,7 @@ Please view this file on the master branch, on stable branches it's out of date.
   - Fix Sign in page 'Forgot your password?' link overlaps on medium-large screens
   - Show full status link on MR & commit pipelines
   - Fix documents and comments on Build API `scope`
+  - Fix applying labels for GitHub-imported MRs
   - Refactor email, use setter method instead AR callbacks for email attribute (Semyon Pupkov)
 
 ## 8.13.1 (2016-10-25)

lib/gitlab/github_import/client.rb

@@ -105,18 +105,20 @@ def request(method, *args, &block)
         data = api.send(method, *args)
         return data unless data.is_a?(Array)
 
+        last_response = api.last_response
+
         if block_given?
           yield data
-          each_response_page(&block)
+          # api.last_response could change while we're yielding (e.g. fetching labels for each PR)
+          # so we cache our own last request
+          each_response_page(last_response, &block)
         else
-          each_response_page { |page| data.concat(page) }
+          each_response_page(last_response) { |page| data.concat(page) }
           data
         end
       end
 
-      def each_response_page
-        last_response = api.last_response
-
+      def each_response_page(last_response)
         while last_response.rels[:next]
           sleep rate_limit_sleep_time if rate_limit_exceed?
           last_response = last_response.rels[:next].get

lib/gitlab/github_import/importer.rb

@@ -132,8 +132,15 @@ def clean_up_restored_branches(pull_request)
       end
 
       def apply_labels(issuable, raw_issuable)
-        if raw_issuable.labels.count > 0
-          label_ids = raw_issuable.labels
+        # GH returns labels for issues but not for pull requests!
+        labels = if issuable.is_a?(MergeRequest)
+                   client.labels_for_issue(repo, raw_issuable.number)
+                 else
+                   raw_issuable.labels
+                 end
+
+        if labels.count > 0
+          label_ids = labels
             .map { |attrs| @labels[attrs.name] }
             .compact
 

spec/lib/gitlab/github_import/importer_spec.rb

@@ -154,6 +154,7 @@
             { type: :label, url: "https://api.github.com/repos/octocat/Hello-World/labels/bug", errors: "Validation failed: Title can't be blank, Title is invalid" },
             { type: :milestone, url: "https://api.github.com/repos/octocat/Hello-World/milestones/1", errors: "Validation failed: Title has already been taken" },
             { type: :issue, url: "https://api.github.com/repos/octocat/Hello-World/issues/1348", errors: "Validation failed: Title can't be blank, Title is too short (minimum is 0 characters)" },
+            { type: :pull_request, url: "https://api.github.com/repos/octocat/Hello-World/pulls/1347", errors: "Invalid Repository. Use user/repo format." },
             { type: :pull_request, url: "https://api.github.com/repos/octocat/Hello-World/pulls/1347", errors: "Validation failed: Validate branches Cannot Create: This merge request already exists: [\"New feature\"]" },
             { type: :wiki, errors: "Gitlab::Shell::Error" },
             { type: :release, url: 'https://api.github.com/repos/octocat/Hello-World/releases/2', errors: "Validation failed: Description can't be blank" }