Doc Editor unable to display individual string fields larger than 486kb in Safari

When testing editing of large documents, I discovered that the Ace JSON editor had a problem in Safari displaying string values larger than approximately 486kb. It doesn't have any problem with large documents, as long as the document is comprised of individual fields that are shorter than 486kb.

 
For example, imagine that the “a_very_long_string” field in the following document had a value that was 500 KiB long:

 
In the document editor it would instead appear as:

You can still edit other fields in the document, but the super long fields will appear blank. This seems to be a bug in the JSON mode of the text editor we are using. So we can handle documents that are much longer, as long as the individual fields are not too long.
 
Note that this problem does not appear in Firefox or Chrome, only Safari.