Fix "Network" and "Graphs" pages for branches with encoded slashes

Closes #1359

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.14.0 (unreleased)
+  - Fix "Network" and "Graphs" pages for branches with encoded slashes (Stan Hu)
   - Fix errors deleting and creating branches with encoded slashes (Stan Hu)
   - Fix multi-line syntax highlighting (Stan Hu)
   - Fix network graph when branch name has single quotes (Stan Hu)

lib/extracts_path.rb

@@ -94,7 +94,7 @@ module ExtractsPath
     @options = params.select {|key, value| allowed_options.include?(key) && !value.blank? }
     @options = HashWithIndifferentAccess.new(@options)
 
-    @id = get_id
+    @id = Addressable::URI.unescape(get_id)
     @ref, @path = extract_ref(@id)
     @repo = @project.repository
     if @options[:extended_sha1].blank?

spec/lib/extracts_path_spec.rb

@@ -29,6 +29,16 @@ describe ExtractsPath do
       assign_ref_vars
       expect(@logs_path).to eq("/#{@project.path_with_namespace}/refs/#{ref}/logs_tree/files/ruby/popen.rb")
     end
+
+    context 'escaped sequences in ref' do
+      let(:ref) { "improve%2Fawesome" }
+
+      it "id should have no escape sequences" do
+        assign_ref_vars
+        expect(@ref).to eq('improve/awesome')
+        expect(@logs_path).to eq("/#{@project.path_with_namespace}/refs/#{ref}/logs_tree/files/ruby/popen.rb")
+      end
+    end
   end
 
   describe '#extract_ref' do