Prefixes source branch name with short SHA to avoid collision

2 files changed, 17 insertions, 9 deletions

diff --git a/lib/gitlab/github_import/branch_formatter.rb b/lib/gitlab/github_import/branch_formatter.rb
index 48bed8fc296..18200809637 100644
--- a/lib/gitlab/github_import/branch_formatter.rb
+++ b/lib/gitlab/github_import/branch_formatter.rb
@@ -15,6 +15,10 @@ module Gitlab
         raw_data.user.login
       end
 
+      def short_sha(length = 7)
+        sha.to_s[0..length]
+      end
+
       private
 
       def branch_exists?
diff --git a/lib/gitlab/github_import/pull_request_formatter.rb b/lib/gitlab/github_import/pull_request_formatter.rb
index 3326fe4bf18..bc24c6de120 100644
--- a/lib/gitlab/github_import/pull_request_formatter.rb
+++ b/lib/gitlab/github_import/pull_request_formatter.rb
@@ -1,8 +1,8 @@
 module Gitlab
   module GithubImport
     class PullRequestFormatter < IssuableFormatter
-      delegate :user, :exists?, :project, :ref, :repo, :sha, to: :source_branch, prefix: true
-      delegate :user, :exists?, :project, :ref, :repo, :sha, to: :target_branch, prefix: true
+      delegate :user, :project, :ref, :repo, :sha, to: :source_branch, prefix: true
+      delegate :user, :exists?, :project, :ref, :repo, :sha, :short_sha, to: :target_branch, prefix: true
 
       def attributes
         {
@@ -39,17 +39,17 @@ module Gitlab
       def source_branch_name
         @source_branch_name ||= begin
           if cross_project?
-            if source_branch_repo
-              "pull/#{number}/#{source_branch_repo.full_name}/#{source_branch_ref}"
-            else
-              "pull/#{number}/#{source_branch_user}/#{source_branch_ref}"
-            end
+            source_branch_name_prefixed
           else
-            source_branch_exists? ? source_branch_ref : "pull/#{number}/#{source_branch_ref}"
+            source_branch_exists? ? source_branch_ref : source_branch_name_prefixed
           end
         end
       end
 
+      def source_branch_name_prefixed
+        "gh-#{target_branch_short_sha}/#{number}"
+      end
+
       def source_branch_exists?
         return false if cross_project?
 
@@ -62,10 +62,14 @@ module Gitlab
 
       def target_branch_name
         @target_branch_name ||= begin
-          target_branch_exists? ? target_branch_ref : "pull/#{number}/#{target_branch_ref}"
+          target_branch_exists? ? target_branch_ref : target_branch_name_prefixed
         end
       end
 
+      def target_branch_name_prefixed
+        "gl-#{target_branch_short_sha}/#{number}"
+      end
+
       def cross_project?
         return true if source_branch_repo.nil?