Source view can fail to render with a javascript error because BaseRevisionCache.getBlameSpans does not always return all the blame spans for a given file

When rendering the source view, ViewFileAction.getBlame() calls Svn2Cache.getBlame to get the blame chunks to render. This in turn calls BaseRevisionCache.getBlameSpans(). This does not always return all the blame spans for a file.

I have not been able to understand the exact cause but the issue can be reproduced by indexing the attached SVN dump and attempting to view source of revision 13. Nothing is shown due to a javascript error, and the javascript error occurs because of incorrectly formed JSON that exists because not all blame spans are returned.

The URL: /browse/try/a/s/asd/q.txt?r1=13&r2=13&u=20