NIFI-4658 set Maximum Number of Entries to required with default valu…

[markobean]

…e of Integer.MAX_VALUE. Fast fail of FlowFiles having fragment.count greater than Max Entries.

Thank you for submitting a contribution to Apache NiFi.

In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:

For all changes:

• Is there a JIRA ticket associated with this PR? Is it referenced
  in the commit message?

• Does your PR title start with NIFI-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.

• Has your PR been rebased against the latest commit within the target branch (typically master)?

• Is your initial contribution a single, squashed commit?

For code changes:

• Have you ensured that the full suite of tests is executed via mvn -Pcontrib-check clean install at the root nifi folder?
• Have you written or updated unit tests to verify your changes?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE file, including the main LICENSE file under nifi-assembly?
• If applicable, have you updated the NOTICE file, including the main NOTICE file found under nifi-assembly?
• If adding new Properties, have you added .displayName in addition to .name (programmatic access) for each of the new properties?

For documentation related changes:

• Have you ensured that format looks appropriate for the output in which it is rendered?

Note:

Please ensure that once the PR is submitted, you check travis-ci for build issues and submit an update to your PR as soon as possible.

[mosermw]

Hi @markobean, I reviewed this and I have a couple of questions. I'm not sure I understand why the throw e; statements were removed from MergeContent. Can you explain or put them back in? Also, in TestMergeContent, I'm not sure why the testDefragmentOldStyleAttributes() test was removed. The test still passes with the rest of your PR applied. Was this perhaps part of the changes made before you modified the PR and force pushed? Thanks for looking into this.

[mosermw]

I see the latest update, and +1 it looks good.