Putting in an overly-large value for a Text field's maximum value breaks things rather horribly

The Text field type settings form allows a "Maximum length" to be anything— including very high values that break the field.

Suggested fix: set a maximum value in validation for the Maximum value text field of whatever is safe. Really, one thousand or two thousand let alone 10,000 or 20,000 should be plenty.

Anyhow, the safe number of characters is more than 20,000 but less than or equal to 25,000 on my MySQL setup.

Here's what happens if you put in 25,000:

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1074 Column length too big for column 'field_otsnaeuhsaotheu_value' (max = 21845); use BLOB or TEXT instead: CREATE TABLE {field_data_field_otsnaeuhsaotheu} ( `entity_type` VARCHAR(128) NOT NULL DEFAULT '' COMMENT 'The entity type this data is attached to', `bundle` VARCHAR(128) NOT NULL DEFAULT '' COMMENT 'The field instance bundle to which this row belongs, used when deleting a field instance', `deleted` TINYINT NOT NULL DEFAULT 0 COMMENT 'A boolean indicating whether this data item has been deleted', `entity_id` INT unsigned NOT NULL COMMENT 'The entity id this data is attached to', `revision_id` INT unsigned NULL DEFAULT NULL COMMENT 'The entity revision id this data is attached to, or NULL if the entity type is not versioned', `language` VARCHAR(32) NOT NULL DEFAULT '' COMMENT 'The language for this data item.', `delta` INT unsigned NOT NULL COMMENT 'The sequence number for this data item, used for multi-value fields', `field_otsnaeuhsaotheu_value` VARCHAR(25000) NULL DEFAULT NULL, `field_otsnaeuhsaotheu_format` VARCHAR(255) NULL DEFAULT NULL, PRIMARY KEY (`entity_type`, `entity_id`, `deleted`, `delta`, `language`), INDEX `entity_type` (`entity_type`), INDEX `bundle` (`bundle`), INDEX `deleted` (`deleted`), INDEX `entity_id` (`entity_id`), INDEX `revision_id` (`revision_id`), INDEX `language` (`language`), INDEX `field_otsnaeuhsaotheu_format` (`field_otsnaeuhsaotheu_format`) ) ENGINE = InnoDB DEFAULT CHARACTER SET utf8 COMMENT 'Data storage for field 30 (field_otsnaeuhsaotheu)'; Array ( ) in db_create_table() (line 2588 of /home/ben/code/dgd7/drupal/includes/database/database.inc).

Trying to set the value back to something safe doesn't fly; this error is returned.

PDOException: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'dgd7.field_data_field_poypi' doesn't exist: SELECT COUNT(*) AS expression FROM (SELECT 1 AS expression FROM {field_data_field_poypi} field_data_field_poypi0 WHERE (field_data_field_poypi0.deleted = :db_condition_placeholder_0) LIMIT 1 OFFSET 0) subquery; Array ( [:db_condition_placeholder_0] => 0 ) in field_sql_storage_field_storage_query() (line 569 of /home/ben/code/dgd7/drupal/modules/field/modules/field_sql_storage/field_sql_storage.module).