From 4754f1e78ab00aa3895d5be93ac2146f2dc97d88 Mon Sep 17 00:00:00 2001
From: James Allen <james@sharelatex.com>
Date: Thu, 15 Feb 2018 11:06:40 +0000
Subject: [PATCH] Use bare objects without prototypes for tracking filenames

---
 .../web/public/coffee/ide/history/HistoryV2Manager.coffee   | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/services/web/public/coffee/ide/history/HistoryV2Manager.coffee b/services/web/public/coffee/ide/history/HistoryV2Manager.coffee
index f5124a71d9..574190c870 100644
--- a/services/web/public/coffee/ide/history/HistoryV2Manager.coffee
+++ b/services/web/public/coffee/ide/history/HistoryV2Manager.coffee
@@ -197,10 +197,12 @@ define [
 
 		_perDocSummaryOfUpdates: (updates) ->
 			# Track current_pathname -> original_pathname
-			original_pathnames = {}
+			# create bare object for use as Map
+			# http://ryanmorr.com/true-hash-maps-in-javascript/
+			original_pathnames = Object.create(null)
 
 			# Map of original pathname -> doc summary
-			docs_summary = {}
+			docs_summary = Object.create(null)
 
 			updatePathnameWithUpdateVersions = (pathname, update, deleted) ->
 				# docs_summary is indexed by the original pathname the doc