dbDelta uses suppressed errors to detect table absence

[andy]

In dbDelta, $tablefields is populated by the statement DESCRIBE {$table}. When the table does not exist, this statement fails with an error. This statement is executed with error suppression enabled.

Handling of suppressed errors is customizable in database drop-ins. In one large case, suppressed errors are logged for analysis. These suppressed DESCRIBE errors are considered a bug because it's possible to check for the presence of a table without errors by using a SHOW TABLES LIKE statement.

It would be preferable to leave error suppression out of dbDelta and use the SHOW TABLES LIKE statement, as in the attached patch.

[andy]

This patch has been deployed on WordPress.com.

[gaupoit]

Query Monitor tool will collect this errors and showing them while the plugin creates custom tables using dbDelta function.