Revert "Issue #2232477 by tstoeckler, a 'fliptable' mateescu, plach: Fixed Fatal when adding new fields with NOT NULL constraints in a base table that contains existing entities."

This reverts commit 08d3ebba69.

core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php

@@ -1415,19 +1415,10 @@ class SqlContentEntityStorageSchema implements DynamicallyFieldableEntityStorage
       // table. For this reason the revision ID field cannot be marked as NOT
       // NULL.
       unset($keys['label'], $keys['revision']);
-
       // Key fields may not be NULL.
       if (in_array($field_name, $keys)) {
         $schema['fields'][$schema_field_name]['not null'] = TRUE;
       }
-      // All the other columns have to be able to be NULL regardless of the
-      // actual field storage schema in order to support adding a base field
-      // definition to an entity type with non-empty base table(s).
-      // @todo Revisit the strict 'not null' => FALSE requirement for all
-      // non-key columns in https://www.drupal.org/node/2346019.
-      elseif (isset($schema['fields'][$schema_field_name]['not null'])) {
-        $schema['fields'][$schema_field_name]['not null'] = FALSE;
-      }
     }
 
     if (!empty($field_schema['indexes'])) {

core/tests/Drupal/Tests/Core/Entity/Sql/SqlContentEntityStorageSchemaTest.php

@@ -220,7 +220,6 @@ class SqlContentEntityStorageSchemaTest extends UnitTestCase {
       'columns' => array(
         'target_id' => array(
           'type' => 'int',
-          'not null' => TRUE,
         ),
         'target_revision_id' => array(
           'type' => 'int',
@@ -316,7 +315,6 @@ class SqlContentEntityStorageSchemaTest extends UnitTestCase {
           'editor_revision__target_id' => array(
             'description' => 'The editor_revision field.',
             'type' => 'int',
-            'not null' => FALSE,
           ),
           'editor_revision__target_revision_id' => array(
             'description' => 'The editor_revision field.',