diff --git a/lib/ace/document.js b/lib/ace/document.js
index b8379854..3cae6399 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -326,6 +326,8 @@ var Document = function(text) {
         if (lines.length == 0)
             return {row: row, column: 0};
 
+        // apply doesn't work for big arrays (smallest threshold is on safari 0xFFFF)
+        // to circumvent that we have to break huge inserts into smaller chunks here
         if (lines.length > 0xFFFF) {
             var end = this.insertLines(row, lines.slice(0xFFFF));
             lines = lines.slice(0, 0xFFFF);