[SourcesManager] Unshallow when updating a specs repo

lib/cocoapods/sources_manager.rb

@@ -625,6 +625,7 @@ module Pod
     end
 
     def update_git_repo(show_output = false)
+      ensure_in_repo!
       Config.instance.with_changes(:verbose => show_output) do
         git!(%w(pull --ff-only))
       end
@@ -635,4 +636,16 @@ module Pod
                 '`pod repo update --verbose`'
     end
   end
+
+  class MasterSource
+    def update_git_repo(show_output = false)
+      ensure_in_repo!
+      if repo.join('.git', 'shallow').file?
+        UI.info "Performing a deep fetch of the `#{name}` specs repo to improve future performance" do
+          git!(%w(fetch --unshallow))
+        end
+      end
+      super
+    end
+  end
 end

spec/unit/sources_manager_spec.rb

@@ -314,6 +314,17 @@ module Pod
         SourcesManager.update(test_repo_path.basename.to_s, true)
       end
 
+      it 'unshallows if the git repo is shallow' do
+        set_up_test_repo_for_update
+        test_repo_path.join('.git', 'shallow').open('w') { |f| f << 'a' * 40 }
+        SourcesManager.expects(:update_search_index_if_needed_in_background).with({}).returns(nil)
+        MasterSource.any_instance.expects(:git!).with(%w(fetch --unshallow))
+        MasterSource.any_instance.expects(:git!).with(%w(pull --ff-only))
+        SourcesManager.update(test_repo_path.basename.to_s, true)
+
+        UI.output.should.match /deep fetch.+`master`.+improve future performance/
+      end
+
       it 'prints a warning if the update failed' do
         set_up_test_repo_for_update
         Source.any_instance.stubs(:git).with(%w(rev-parse HEAD)).returns('aabbccd')