Treat Repository instances with the same disk path as the same hash key

app/models/repository.rb

@@ -69,7 +69,13 @@ class Repository
   end
 
   def ==(other)
-    @disk_path == other.disk_path
+    other.is_a?(self.class) && @disk_path == other.disk_path
+  end
+
+  alias_method :eql?, :==
+
+  def hash
+    [self.class, @disk_path].hash
   end
 
   def raw_repository

lib/gitlab/diff/diff_refs.rb

@@ -23,7 +23,7 @@ module Gitlab
       alias_method :eql?, :==
 
       def hash
-        [base_sha, start_sha, head_sha].hash
+        [self.class, base_sha, start_sha, head_sha].hash
       end
 
       # There is only one case in which we will have `start_sha` and `head_sha`,

lib/gitlab/git/repository.rb

@@ -80,7 +80,13 @@ module Gitlab
       end
 
       def ==(other)
-        [storage, relative_path] == [other.storage, other.relative_path]
+        other.is_a?(self.class) && [storage, relative_path] == [other.storage, other.relative_path]
+      end
+
+      alias_method :eql?, :==
+
+      def hash
+        [self.class, storage, relative_path].hash
       end
 
       # This method will be removed when Gitaly reaches v1.1.