Install fail if DO_NOT_UPGRADE_GLOBAL_TABLES flag is true

[spacedmonkey]

WordPress fails to install with DO_NOT_UPGRADE_GLOBAL_TABLES flag set to true in wp-config.php file. There is no error message, you get to the final install screen, but the wp_user and wp_usermeta tables haven't created.

[jorbin]

For this to happen you’d either have to create your own wp-config file before installation, or add that constant if WP can’t create it itself.

I think the answer for this is to display a warning on the install screen if DO_NOT_UPGRADE_GLOBAL_TABLES is defined as true. We have a precedent for this in src/wp-admin/network.php for displaying a message if you attempt to create a network with the constant defined.

[Oxymoron]

Added error message if DO_NOT_UPGRADE_GLOBAL_TABLES is defined & true

[Oxymoron]

Screenshot of the error message 32011.patch adds

[jorbin]

In 32714:

Add error if a user attempts to install WordPress with DO_NOT_UPGRADE_GLOBAL_TABLES defined

The install process runs through migrations to global tables, therefore we cannot install WordPress with this constant defined. This error message prevents a false success screen from being seen.

Fixes #32011.
Props Oxymoron.

[ocean90]

We don't bother with truthiness for the DO_NOT_UPGRADE_GLOBAL_TABLES global, should be just if ( defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) {}.

[jorbin]

Actually we are fairly inconsistant.

Sometimes We just check for definition.
Other times we check for basic truthiness.

We may want to standardize on one or the other.

[ocean90]

Replying to jorbin:

We may want to standardize on one or the other.

#blamepento :-) #32154 covers the others.

[jorbin]

In 32715:

Remove Truthy check from DO_NOT_UPGRADE_GLOBAL_TABLES

Some, but not all, of the checks for DO_NOT_UPGRADE_GLOBAL_TABLES just check if it is defined, so checking for truthiness could cause the issue to not be fully fixed.

In the words of Colonel Jessep: You can't handle the truth!

Introduced in [32714]

Fixes #32011