Record error messages from mid-batch exceptions
Problem/Motivation
If an error occurs during the update batch job, our error handling isn't great; the batch job will fail and the error page will only contain "Update error" as the message. That's not awesome.
Steps to reproduce
Proposed resolution
The batch processor should be able to catch exceptions, record their messages (with special handling for UpdateException) and ensure that they are displayed as error messages.
Remaining tasks
User interface changes
API changes
Data model changes
Edited by drupalbot