dev/core#1383: Fix Re-Installation of Extensions With Logging Enabled

[MiyaNoctem]

Overview

If logging is enabled, CiviCRM will create log tables for every table in the CiviCRM Schema. If an extension added custom groups and fields, logging tables for those custom groups will be created. When the extension is uninstalled, custom groups and fields will get deleted. However, logging tables will remain unaffected. This may be desireable behaviour (ie. keeping the log of tables that used to exist in DB), but if the extension is re-installed, current handling of custom fields will cause a DB error, as fields will try to be added again to the logging tables as duplicates.

Before

When uninstalling an extension, logging tables associated to custom groups and fields will not be deleted. On re-installation, addition of custom fields will cause DB errors to be thrown, as columns existing on logging tables are tried to be created again (they already exist on logging tables, as they were never removed).

After

Fixed by checking if the column exists on log table before trying to create it, treating it as a modification of the schema if it exists.

[civibot]

(Standard links)

• If this is your first pull-request for CiviCRM, please browse CONTRIBUTING.md for information about the development and testing processes.
• If you are reviewing this pull-request, you may wish to consult the test sites and the Review Standards (long template, short template).

[eileenmcnaughton]

@MiyaNoctem I haven't had a chance to look at this yet - but my take is it should probably be against 5.20 branch as I think it's a regression?

[MiyaNoctem]

@eileenmcnaughton I've re-based the fix on v5.20 release candidate branch.

[eileenmcnaughton]

This took a bit to replicate as I hit other problems on the extension I first tried it on (accountsync with some datefield issues in strict mode) before realising it only applies if the extension is installing AND uninstalling custom groups. A lot of extensions install custom groups - very few remove them on install but the one mentioned in the ticket attempts to (it actually fails though in my testing as they were not inconsistently removed). I wound up hacking the custom table our manually after uninstall and at that point hit the described issue on re-install.

I agree that this fixes it and that it seems like a sensible change. On review I think I was wrong in thinking this was an rc-issue as it doesn't seem like part of the seemingly-related issues but at this stage I'm going to merge as is (against the rc) anyway.

These are the enotices I got installing the extension