Changing JS files can make combining/minification produce reference errors

[GoogleCodeExporter]

1. make an HTML file referencing scripts a.js and b.js
2. enable rewrite_javascript and combine_javascript (both in core now)
3. rewrite the HTML file producing combined minified URL e.g.
   a.js,Mjm.HASH.js+b.js,Mjm.HASH.js.pagespeed.jc.HASH.js
4. somehow the metadata cache for the combination stays present but
   the http cache and the metadata cache for the minifications
   is flushed
5. change an identifier in a.js
6. refetch the combined minified file

I believe this will result in ReferenceErrors e.g. mod_pagespeed_63jkvFJpbY1 is 
not defined.

This has not been repro'd yet but should be easy to unit test.

Original issue reported on code.google.com by jmara...@google.com on 31 Jan 2014 at 2:07

• Blocking: combine_javascript ReferenceError #558