From:  "Fitzgerald, Nick" <nfitzgerald@mozilla.com>
Date:  16 Oct 2013 07:05:04 Hong Kong Time
Newsgroup:  news.mozilla.org/mozilla.dev.js-sourcemap
Subject:  

Re: Correct approach for bundles that contain more than original source

NNTP-Posting-Host:  63.245.216.66

On 10/14/13 1:21 PM, James Burke wrote:
> My understanding is that source maps support the bundle file having segments that do not map back to a file that is mapped. 

Correct. This would be the case where a mapping segment has only a
single VLQ.

https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit?pli=1#heading=h.qz3o9nc69um5

> So I want to confirm that what I am doing is correct use of the API for skipping the added \n between bundled files. If so, then I will contact the UglifyJS2 project to see if there is a bug on its consumption of the source map for their own source map generation.

Yes, this sounds like a bug on Uglify's end.