Extract the longest-matching ref from a commit path when multiple matches occur

Closes #1839

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/extracts_path.rb b/lib/extracts_path.rb
index 6e4ed01e079..3f420553d42 100644
--- a/lib/extracts_path.rb
+++ b/lib/extracts_path.rb
@@ -55,12 +55,16 @@ module ExtractsPath
       valid_refs = @project.repository.ref_names
       valid_refs.select! { |v| id.start_with?("#{v}/") }
 
-      if valid_refs.length != 1
+      if valid_refs.length == 0
         # No exact ref match, so just try our best
         pair = id.match(/([^\/]+)(.*)/).captures
       else
+        # There is a distinct possibility that multiple refs prefix the ID.
+        # Use the longest match to maximize the chance that we have the
+        # right ref.
+        best_match = valid_refs.max_by(&:length)
         # Partition the string into the ref and the path, ignoring the empty first value
-        pair = id.partition(valid_refs.first)[1..-1]
+        pair = id.partition(best_match)[1..-1]
       end
     end