Verify upgrade path from v6.x-1.12-x

At the very least we should add an update script that throws warnings and/or blocks the update if you attempt to run the update if the new 6.x-2.x code has been used.

The following tables exist for both Nodewords v6.x-1.x-dev and v6.x-2.x-dev:

• nodewords
• nodewords_custom

I've reviewed the schema for both tables and they look exactly the same. The next step is to examine the data created by both to see if there are any changes in what is actually stored.

Possible items:

• Any metatag that was built with tokens will have to be rebuilt another way as tokens are no longer supported.
• In v2 the frontpage has to have its tags configured like any other custom page using the Custom Page sub-module (despite having lots of the old functionality for the built-in handling still in place). Downgrading to v1 would mean that the frontpage settings would not show in the "Specific meta tags" subpage, instead they would still show in the Custom Pages list; there could be a potential conflict if older values existing for the Specific settings and Custom Pages settings also existed.

Any others?

Problems:

1. Tokens - 6.x-1.12 has them, 6.x-1.13 does not.
2. hook_update_n() - 6.x-1.12 was up to 6179 whereas 1.13 is (currently) only up to 6175. As a result, when you run update.php it tries to run ALL updates up to that point, which could break your site :-|

This patch should resolve the second issue, where it would try to re-run all updates when updating from a 6.x-1.12- version. It also will display the following message:

You are updating from 6.x-1.12. A lot of code has been reverted, specifically the Tokens support has temporarily been removed. You should not have lost any data, but please be aware that any meta tags which depended upon Tokens will not work correctly. As a temporary solution you may wish to test the 6.x-2.0-alpha1 version, until Tokens can be added back into version 6.x-1.x again.

This version deletes values from the 'system' table for the defunct submodules.

Fixed the $ret values, improved the message slightly.

I've committed this code.

How did you update the files? Are you sure all of the old files were deleted? In the fresh 6.x-1.x codebase the function nodewords_custom_pages_confirm_delete() only exists in nodewords.admin.inc, whereas in 6.x-1.12-x it was in nodewords_admin.admin.inc.

@pbeakley: Please try deleting the Nodewords files again, make sure you don't have another copy of the module somewhere else in the site's directory structure, clear all site caches and then download 6.x-1.13 again.