? sites/default/modules
? sites/default/settings.php
Index: includes/actions.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/actions.inc,v
retrieving revision 1.22
diff -u -p -r1.22 actions.inc
--- includes/actions.inc	8 Nov 2008 07:28:03 -0000	1.22
+++ includes/actions.inc	15 Nov 2008 10:02:58 -0000
@@ -236,7 +236,7 @@ function actions_function_lookup($hash) 
   }
 
   // Must be an instance; must check database.
-  return db_query("SELECT aid FROM {actions} WHERE MD5(aid) = :hash AND parameters <> ''", array(':hash' => $hash))->fetchField();
+  return db_query("SELECT aid FROM {actions} WHERE MD5(aid) = :hash AND parameters IS NOT NULL", array(':hash' => $hash))->fetchField();
 }
 
 /**
@@ -251,7 +251,7 @@ function actions_synchronize($actions_in
   if (!$actions_in_code) {
     $actions_in_code = actions_list(TRUE);
   }
-  $actions_in_db = db_query("SELECT aid, callback, description FROM {actions} WHERE parameters = ''")->fetchAllAssoc('callback', PDO::FETCH_ASSOC);
+  $actions_in_db = db_query("SELECT aid, callback, description FROM {actions} WHERE parameters IS NULL")->fetchAllAssoc('callback', PDO::FETCH_ASSOC);
 
   // Go through all the actions provided by modules.
   foreach ($actions_in_code as $callback => $array) {
@@ -269,7 +269,7 @@ function actions_synchronize($actions_in
             'aid' => $callback,
             'type' => $array['type'],
             'callback' => $callback,
-            'parameters' => '',
+            'parameters' => NULL,
             'description' => $array['description'],
             ))
           ->execute();
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.302
diff -u -p -r1.302 form.inc
--- includes/form.inc	10 Nov 2008 05:22:59 -0000	1.302
+++ includes/form.inc	15 Nov 2008 10:02:59 -0000
@@ -2603,7 +2603,8 @@ function batch_process($redirect = NULL,
       // at least an empty string for the (not null) 'token' column.
       $batch['id'] = db_insert('batch')
         ->fields(array(
-          'token' => '',
+          // token will soon replace with db_update().
+          'token' => 'default',
           'timestamp' => REQUEST_TIME,
         ))
         ->execute();
Index: includes/locale.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/locale.inc,v
retrieving revision 1.194
diff -u -p -r1.194 locale.inc
--- includes/locale.inc	11 Nov 2008 20:22:17 -0000	1.194
+++ includes/locale.inc	15 Nov 2008 10:02:59 -0000
@@ -426,7 +426,7 @@ function locale_languages_delete_form_su
     _locale_rebuild_js($form_state['values']['langcode']);
     // Remove the language.
     db_query("DELETE FROM {languages} WHERE language = '%s'", $form_state['values']['langcode']);
-    db_query("UPDATE {node} SET language = '' WHERE language = '%s'", $form_state['values']['langcode']);
+    db_query("UPDATE {node} SET language = NULL WHERE language = '%s'", $form_state['values']['langcode']);
     $variables = array('%locale' => $languages[$form_state['values']['langcode']]->name);
     drupal_set_message(t('The language %locale has been removed.', $variables));
     watchdog('locale', 'The language %locale has been removed.', $variables);
Index: includes/database/database.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/database.inc,v
retrieving revision 1.28
diff -u -p -r1.28 database.inc
--- includes/database/database.inc	15 Nov 2008 08:23:06 -0000	1.28
+++ includes/database/database.inc	15 Nov 2008 10:02:59 -0000
@@ -224,6 +224,7 @@ abstract class DatabaseConnection extend
 
     // Because the other methods don't seem to work right.
     $driver_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
+    $driver_options[PDO::ATTR_ORACLE_NULLS] = PDO::NULL_EMPTY_STRING;
 
     // Call PDO::__construct and PDO::setAttribute.
     parent::__construct($dsn, $username, $password, $driver_options);
@@ -454,6 +455,12 @@ abstract class DatabaseConnection extend
     // Use default values if not already set.
     $options += $this->defaultOptions();
 
+  foreach ($args as &$arg) {
+    if ($arg === '') {
+      $arg = NULL;
+    }
+  }
+
     try {
       // We allow either a pre-bound statement object or a literal string.
       // In either case, we want to end up with an executed statement object,
@@ -2243,6 +2250,23 @@ function _db_query_process_args($query, 
     $options['target'] = 'default';
   }
 
+  // TODO: temporary replace '' as NULL here.
+  foreach ($args as &$arg) {
+    if ($arg === '') {
+      $arg = NULL;
+    }
+  }
+
+  // TODO: remove debug
+  openlog("drupal", LOG_PID | LOG_PERROR, LOG_LOCAL0);
+  if (preg_match("/''/", $query)) {
+    syslog(LOG_ERR, "INLINE EMPTY STRING: " . $query);
+  }
+  if (in_array('', $args, TRUE)) {
+    syslog(LOG_ERR, "ARGS EMPTY STRING: " . $query . ' ' . array_search('', $args, TRUE));
+  }
+  closelog();
+
   // Temporary backward-compatibliity hacks.  Remove later.
   $old_query = $query;
   $query = str_replace(array('%n', '%d', '%f', '%b', "'%s'", '%s'), '?', $old_query);
Index: modules/block/block.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.install,v
retrieving revision 1.13
diff -u -p -r1.13 block.install
--- modules/block/block.install	15 Nov 2008 08:23:07 -0000	1.13
+++ modules/block/block.install	15 Nov 2008 10:02:59 -0000
@@ -16,8 +16,7 @@ function block_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("The module from which the block originates; for example, 'user' for the Who's Online block, and 'block' for any custom blocks."),
       ),
       'delta' => array(
@@ -30,8 +29,7 @@ function block_schema() {
       'theme' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('The theme under which the block settings apply.'),
       ),
       'status' => array(
@@ -51,8 +49,7 @@ function block_schema() {
       'region' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Theme region within which the block is set.'),
       ),
       'custom' => array(
@@ -71,14 +68,13 @@ function block_schema() {
       ),
       'pages' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('Contents of the "Pages" block; contains either a list of paths on which to include/exclude the block or PHP code, depending on "visibility" setting.'),
       ),
       'title' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Custom title for the block. (Empty string will use block default title, &lt;none&gt; will remove the title, text will cause block to use specified title.)'),
       ),
       'cache' => array(
@@ -104,13 +100,13 @@ function block_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t("The block's origin module, from {block}.module."),
       ),
       'delta' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t("The block's unique delta within module, from {block}.delta."),
       ),
       'rid' => array(
@@ -144,8 +140,7 @@ function block_schema() {
       'info' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Block description.'),
       ),
       'format' => array(
@@ -167,3 +162,85 @@ function block_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Block updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function block_update_7001() {
+  $ret = array();
+
+  $schema['block'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'theme' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'region' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'pages' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['block_role'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'delta' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['box'] = array(
+    'fields' => array(
+      'info' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_block'] = drupal_get_schema_unprocessed('system', 'cache');  
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/dblog/dblog.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/dblog/dblog.install,v
retrieving revision 1.9
diff -u -p -r1.9 dblog.install
--- modules/dblog/dblog.install	22 Oct 2008 18:32:31 -0000	1.9
+++ modules/dblog/dblog.install	15 Nov 2008 10:02:59 -0000
@@ -38,19 +38,18 @@ function dblog_schema() {
       'type' => array(
         'type' => 'varchar',
         'length' => 16,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Type of log message, for example "user" or "page not found."'),
       ),
       'message' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => t('Text of log message to be passed into the t() function.'),
       ),
       'variables' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => t('Serialized array of variables that match the message string and that is passed into the t() function.'),
       ),
@@ -66,26 +65,23 @@ function dblog_schema() {
         'type' => 'varchar',
         'length' => 255,
         'not null' => FALSE,
-        'default' => '',
         'description' => t('Link to view the result of the event.'),
       ),
       'location'  => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('URL of the origin of the event.'),
       ),
       'referer' => array(
         'type' => 'varchar',
         'length' => 128,
         'not null' => FALSE,
-        'default' => '',
         'description' => t('URL of referring page.'),
       ),
       'hostname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Hostname of the user who triggered the event.'),
       ),
       'timestamp' => array(
@@ -106,6 +102,11 @@ function dblog_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Database logging updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Allow NULL values for links.
  */
 function dblog_update_7001() {
@@ -123,3 +124,63 @@ function dblog_update_7002() {
   db_add_index($ret, 'watchdog', 'uid', array('uid'));
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function dblog_update_7003() {
+  $ret = array();
+
+  $schema['watchdog'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 16,
+        'not null' => FALSE,
+      ),
+      'message' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'variables' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'link' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'referer' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'location'  => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/filter/filter.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/filter/filter.install,v
retrieving revision 1.9
diff -u -p -r1.9 filter.install
--- modules/filter/filter.install	14 Apr 2008 17:48:37 -0000	1.9
+++ modules/filter/filter.install	15 Nov 2008 10:02:59 -0000
@@ -22,8 +22,7 @@ function filter_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('The origin module of the filter.'),
       ),
       'delta' => array(
@@ -60,15 +59,13 @@ function filter_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Name of the input format (Filtered HTML).'),
       ),
       'roles' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('A comma-separated string of roles; references {role}.rid.'), // This is bad since you can't use joins, nor index.
       ),
       'cache' => array(
@@ -99,6 +96,11 @@ function filter_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Filter updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Add a weight column to the filter formats table.
  */
 function filter_update_7000() {
@@ -122,3 +124,51 @@ function filter_update_7001() {
   }
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function filter_update_7002() {
+  $ret = array();
+
+  $schema['filters'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['filter_formats'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'roles' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_filter'] = drupal_get_schema_unprocessed('system', 'cache');
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/locale/locale.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/locale/locale.install,v
retrieving revision 1.30
diff -u -p -r1.30 locale.install
--- modules/locale/locale.install	14 Apr 2008 17:48:37 -0000	1.30
+++ modules/locale/locale.install	15 Nov 2008 10:03:00 -0000
@@ -12,7 +12,7 @@ function locale_install() {
   // Create tables.
   drupal_install_schema('locale');
 
-  db_query("INSERT INTO {languages} (language, name, native, direction, enabled, weight, javascript) VALUES ('en', 'English', 'English', '0', '1', '0', '')");
+  db_query("INSERT INTO {languages} (language, name, native, direction, enabled, weight, javascript) VALUES ('en', 'English', 'English', '0', '1', '0', NULL)");
 }
 
 /**
@@ -206,6 +206,102 @@ function locale_update_6005() {
  */
 
 /**
+ * @defgroup updates-6.x-to-7.x Locale updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function locale_update_7000() {
+  $ret = array();
+
+  $schema['languages'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => FALSE,
+      ),
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'native' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'formula' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'domain' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'prefix' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'javascript' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['locales_source'] = array(
+    'fields' => array(
+      'location' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'source' => array(
+        'type' => 'text',
+        'mysql_type' => 'blob',
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['locales_target'] = array(
+    'fields' => array(
+      'translation' => array(
+        'type' => 'text',
+        'mysql_type' => 'blob',
+        'not null' => FALSE,
+      ),
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
+
+/**
  * Implementation of hook_uninstall().
  */
 function locale_uninstall() {
@@ -231,22 +327,19 @@ function locale_schema() {
       'language' => array(
         'type' => 'varchar',
         'length' => 12,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("Language code, e.g. 'de' or 'en-US'."),
       ),
       'name' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Language name in English.'),
       ),
       'native' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Native language name.'),
       ),
       'direction' => array(
@@ -270,22 +363,19 @@ function locale_schema() {
       'formula' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Plural formula in PHP code to evaluate to get plural indexes.'),
       ),
       'domain' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Domain to use for this language.'),
       ),
       'prefix' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Path prefix to use for this language.'),
       ),
       'weight' => array(
@@ -297,8 +387,7 @@ function locale_schema() {
       'javascript' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Location of JavaScript translation file.'),
       ),
     ),
@@ -319,8 +408,7 @@ function locale_schema() {
       'location' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Drupal path in case of online discovered translations or file path in case of imported strings.'),
       ),
       'textgroup' => array(
@@ -333,7 +421,7 @@ function locale_schema() {
       'source' => array(
         'type' => 'text',
         'mysql_type' => 'blob',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('The original string in English.'),
       ),
       'version' => array(
@@ -362,14 +450,13 @@ function locale_schema() {
       'translation' => array(
         'type' => 'text',
         'mysql_type' => 'blob',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('Translation string value in this language.'),
       ),
       'language' => array(
         'type' => 'varchar',
         'length' => 12,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Language code. References {languages}.language.'),
       ),
       'plid' => array(
Index: modules/node/node.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.install,v
retrieving revision 1.7
diff -u -p -r1.7 node.install
--- modules/node/node.install	8 Oct 2008 03:27:56 -0000	1.7
+++ modules/node/node.install	15 Nov 2008 10:03:00 -0000
@@ -25,22 +25,19 @@ function node_schema() {
         'description' => t('The {node_type}.type of this node.'),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'language' => array(
         'description' => t('The {languages}.language of this node.'),
         'type' => 'varchar',
         'length' => 12,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title' => array(
         'description' => t('The title of this node, always treated as non-markup plain text.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'uid' => array(
         'description' => t('The {users}.uid that owns this node; initially, this is the user that created it.'),
@@ -143,8 +140,7 @@ function node_schema() {
         'description' => t('The realm in which the user must possess the grant ID. Each node access node can define one or more realms.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'grant_view' => array(
         'description' => t('Boolean indicating whether a user with the realm/grant pair can view this node.'),
@@ -236,25 +232,24 @@ function node_schema() {
         'description' => t('The title of this version.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'body' => array(
         'description' => t('The body of this version.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'teaser' => array(
         'description' => t('The teaser of this version.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'log' => array(
         'description' => t('The log entry explaining the changes in this version.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'timestamp' => array(
@@ -284,31 +279,30 @@ function node_schema() {
         'description' => t('The machine-readable name of this type.'),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'name' => array(
         'description' => t('The human-readable name of this type.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'base' => array(
         'description' => t('The base string used to construct callbacks corresponding to this node type.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'description' => array(
         'description' => t('A brief description of this type.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'medium',
       ),
       'help' => array(
         'description' => t('Help information shown to the user when creating a {node} of this type.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'medium',
       ),
       'has_title' => array(
@@ -322,8 +316,7 @@ function node_schema() {
         'description' => t('The label displayed for the title field on the edit form.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'has_body' => array(
         'description' => t('Boolean indicating whether this type uses the {node_revisions}.body field.'),
@@ -336,8 +329,7 @@ function node_schema() {
         'description' => t('The label displayed for the body field on the edit form.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'min_word_count' => array(
         'description' => t('The minimum number of words the body must contain.'),
@@ -371,8 +363,7 @@ function node_schema() {
         'description' => t('The original machine-readable name of this node type. This may be different from the current type name if the locked field is 0.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'primary key' => array('type'),
@@ -382,7 +373,8 @@ function node_schema() {
 }
 
 /**
- * Drupal 6.x to 7.x updates
+ * @defgroup updates-6.x-to-7.x Node updates from 6.x to 7.x
+ * @{
  */
 
 /**
@@ -398,5 +390,122 @@ function node_update_7000() {
 }
 
 /**
- * End of 6.x to 7.x updates
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function node_update_7001() {
+  $ret = array();
+
+  $schema['node'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['node_access'] = array(
+    'fields' => array(
+      'realm' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['node_revisions'] = array(
+    'fields' => array(
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'body' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'teaser' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'log' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),      
+    ),
+  );
+
+  $schema['node_type'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'base' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'medium',
+      ),
+      'help' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'medium',
+      ),
+      'title_label' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'body_label' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'orig_type' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
  */
Index: modules/php/php.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/php/php.install,v
retrieving revision 1.2
diff -u -p -r1.2 php.install
--- modules/php/php.install	14 Apr 2008 17:48:41 -0000	1.2
+++ modules/php/php.install	15 Nov 2008 10:03:00 -0000
@@ -11,7 +11,7 @@ function php_install() {
   // reliable method to identify the format in an uninstall hook or in
   // subsequent clean installs.
   if (!$format_exists) {
-    db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('PHP code', '', 0)");
+    db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('PHP code', NULL, 0)");
     $format = db_result(db_query("SELECT MAX(format) FROM {filter_formats}"));
 
     // Enable the PHP evaluator filter.
Index: modules/simpletest/simpletest.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/simpletest.install,v
retrieving revision 1.13
diff -u -p -r1.13 simpletest.install
--- modules/simpletest/simpletest.install	9 Nov 2008 05:50:48 -0000	1.13
+++ modules/simpletest/simpletest.install	15 Nov 2008 10:03:00 -0000
@@ -148,34 +148,30 @@ function simpletest_schema() {
       'test_class' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('The name of the class that created this message.'),
       ),
       'status' => array(
         'type' => 'varchar',
         'length' => 9,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Message status. Core understands pass, fail, exception.'),
       ),
       'message' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('The message itself.'),
       ),
       'message_group' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('The message group this message belongs to. For example: warning, browser, user.'),
       ),
       'function' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Name of the assertion function or method that created this message.'),
       ),
       'line' => array(
@@ -187,8 +183,7 @@ function simpletest_schema() {
       'file' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Name of the file where the function is called.'),
       ),
     ),
@@ -211,3 +206,63 @@ function simpletest_schema() {
   );
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x SimpleTest updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function simpletest_update_7000() {
+  $ret = array();
+
+  $schema['simpletest'] = array(
+    'fields' => array(
+      'test_class' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'status' => array(
+        'type' => 'varchar',
+        'length' => 9,
+        'not null' => FALSE,
+      ),
+      'message' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'message_group' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'function' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'file' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/system/system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.104
diff -u -p -r1.104 system.admin.inc
--- modules/system/system.admin.inc	11 Nov 2008 22:39:59 -0000	1.104
+++ modules/system/system.admin.inc	15 Nov 2008 10:03:00 -0000
@@ -1772,7 +1772,7 @@ function system_status($check = FALSE) {
   }
   // MySQL import might have set the uid of the anonymous user to autoincrement
   // value. Let's try fixing it. See http://drupal.org/node/204411
-  db_query("UPDATE {users} SET uid = uid - uid WHERE name = '' AND pass = '' AND status = 0");
+  db_query("UPDATE {users} SET uid = uid - uid WHERE name = NULL AND pass = NULL AND status = 0");
 
   return theme('status_report', $requirements);
 }
Index: modules/system/system.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.install,v
retrieving revision 1.279
diff -u -p -r1.279 system.install
--- modules/system/system.install	15 Nov 2008 08:23:07 -0000	1.279
+++ modules/system/system.install	15 Nov 2008 10:03:00 -0000
@@ -351,7 +351,7 @@ function system_install() {
   // uid 2 which is not what we want. So we insert the first user here, the
   // anonymous user. uid is 1 here for now, but very soon it will be changed
   // to 0.
-  db_query("INSERT INTO {users} (name, mail) VALUES('%s', '%s')", '', '');
+  db_query("INSERT INTO {users} (name, mail) VALUES(NULL, NULL)");
   // We need some placeholders here as name and mail are uniques and data is
   // presumed to be a serialized array. Install will change uid 1 immediately
   // anyways. So we insert the superuser here, the uid is 2 here for now, but
@@ -359,7 +359,7 @@ function system_install() {
   db_query("INSERT INTO {users} (name, mail, created, status, data) VALUES('%s', '%s', %d, %d, '%s')", 'placeholder-for-uid-1', 'placeholder-for-uid-1', REQUEST_TIME, 1, serialize(array()));
   // This sets the above two users uid 0 (anonymous). We avoid an explicit 0
   // otherwise MySQL might insert the next auto_increment value.
-  db_query("UPDATE {users} SET uid = uid - uid WHERE name = '%s'", '');
+  db_query("UPDATE {users} SET uid = uid - uid WHERE name IS NULL");
   // This sets uid 1 (superuser). We skip uid 2 but that's not a big problem.
   db_query("UPDATE {users} SET uid = 1 WHERE name = '%s'", 'placeholder-for-uid-1');
 
@@ -378,15 +378,15 @@ function system_install() {
 
   db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'theme_default', 's:7:"garland";');
   db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 1, 'theme', 'garland');
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'login', 'garland', 1, 0, 'left', '', -1);
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'navigation', 'garland', 1, 0, 'left', '', -1);
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'system', 'powered-by', 'garland', 1, 10, 'footer', '', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'user', 'login', 'garland', 1, 0, 'left', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'user', 'navigation', 'garland', 1, 0, 'left', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'system', 'powered-by', 'garland', 1, 10, 'footer', -1);
 
   db_query("INSERT INTO {node_access} (nid, gid, realm, grant_view, grant_update, grant_delete) VALUES (%d, %d, '%s', %d, %d, %d)", 0, 0, 'all', 1, 0, 0);
 
   // Add input formats.
   db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Filtered HTML', ',1,2,', 1);
-  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Full HTML', '', 1);
+  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Full HTML', NULL, 1);
 
   // Enable filters for each input format.
 
@@ -431,13 +431,12 @@ function system_schema() {
         'description' => t('The name of the variable.'),
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'value' => array(
         'description' => t('The value of the variable.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
     ),
@@ -458,20 +457,18 @@ function system_schema() {
         'description' => t('The object that that action acts on (node, user, comment, system or custom types.)'),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'callback' => array(
         'description' => t('The callback function that executes when the action runs.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'parameters' => array(
         'description' => t('Parameters to be passed to the callback function.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'description' => array(
@@ -511,7 +508,7 @@ function system_schema() {
         'description' => t("A string token generated against the current user's session id and the batch id, used to ensure that only the user who submitted the batch can effectively access it."),
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => t('A Unix timestamp indicating when this batch was submitted for processing. Stale batches are purged at cron time.'),
@@ -544,8 +541,7 @@ function system_schema() {
         'description' => t('IP address'),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'indexes' => array(
@@ -561,8 +557,7 @@ function system_schema() {
         'description' => t('Primary Key: Unique cache ID.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'data' => array(
         'description' => t('A collection of data to cache.'),
@@ -630,22 +625,19 @@ function system_schema() {
         'description' => t('Name of the file with no path components. This may differ from the basename of the filepath if the file is renamed to avoid overwriting an existing file.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filepath' => array(
         'description' => t('Path of the file relative to Drupal root.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filemime' => array(
         'description' => t("The file's MIME type."),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filesize' => array(
         'description' => t('The size of the file in bytes.'),
@@ -688,15 +680,13 @@ function system_schema() {
         'description' => t('Name of event (e.g. contact).'),
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'hostname' => array(
         'description' => t('Hostname of the visitor.'),
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => t('Timestamp of the event.'),
@@ -745,25 +735,23 @@ function system_schema() {
         'description' => t('Primary Key: the Drupal path this entry describes'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'load_functions' => array(
         'description' => t('A serialized array of function names (like node_load) to be called to load an object corresponding to a part of the current path.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'to_arg_functions' => array(
         'description' => t('A serialized array of function names (like user_uid_optional_to_arg) to be called to replace a part of the router path with another string.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'access_callback' => array(
         'description' => t('The callback which determines the access to this router path. Defaults to user_access.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'access_arguments' => array(
         'description' => t('A serialized array of arguments for the access callback.'),
@@ -774,8 +762,7 @@ function system_schema() {
         'description' => t('The name of the function that renders the page.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'page_arguments' => array(
         'description' => t('A serialized array of arguments for the page callback.'),
@@ -799,36 +786,31 @@ function system_schema() {
         'description' => t('Only for local tasks (tabs) - the router path of the parent page (which may also be a local task).'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'tab_root' => array(
         'description' => t('Router path of the closest non-tab parent page. For pages that are not local tasks, this will be the same as the path.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title' => array(
         'description' => t('The title for the current page, or the title for the tab if this is a local task.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title_callback' => array(
         'description' => t('A function which will alter the title. Defaults to t()'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title_arguments' => array(
         'description' => t('A serialized array of arguments for the title callback. If empty, the title will be used as the sole argument for the title callback.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type' => array(
         'description' => t('Numeric representation of the type of the menu item, like MENU_LOCAL_TASK.'),
@@ -840,20 +822,18 @@ function system_schema() {
         'description' => t('Name of a function used to render the block on the system administration page for this item.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'description' => array(
         'description' => t('A description of this item.'),
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'position' => array(
         'description' => t('The position of the block (left or right) on the system administration page for this item.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'weight' => array(
         'description' => t('Weight of the element. Lighter weights are higher up, heavier weights go down.'),
@@ -876,8 +856,7 @@ function system_schema() {
         'description' => t("The menu name. All links with the same menu name (such as 'navigation') are part of the same menu."),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'mlid' => array(
         'description' => t('The menu link ID (mlid) is the integer primary key.'),
@@ -896,22 +875,19 @@ function system_schema() {
         'description' => t('The Drupal path or external path this link points to.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'router_path' => array(
         'description' => t('For links corresponding to a Drupal path (external = 0), this connects the link to a {menu_router}.path for joins.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'link_title' => array(
       'description' => t('The text displayed for the link, which may be modified by a title callback stored in {menu_router}.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'options' => array(
         'description' => t('A serialized array of options to be passed to the url() or l() function, such as a query string or HTML attributes.'),
@@ -1060,35 +1036,31 @@ function system_schema() {
         'description' => t('The name of the function, class, or interface.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type'   => array(
         'description' => t('Either function or class or interface.'),
         'type' => 'varchar',
         'length' => 9,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filename'   => array(
         'description' => t('Name of the file.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'module' => array(
         'description' => t('Name of the module the file belongs to.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => ''
+        'not null' => FALSE,
       ),
       'suffix' => array(
         'description' => t("The part of the function name after the module, which is the hook this function implements, if any."),
         'type' => 'varchar',
         'length' => 68,
-        'not null' => TRUE,
-        'default' => ''
+        'not null' => FALSE,
       ),
       'weight' => array(
         'description' => t("The order in which this module's hooks should be invoked relative to other modules. Equal-weighted modules are ordered by name."),
@@ -1110,13 +1082,13 @@ function system_schema() {
         'description' => t('Path to the file.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'md5'  => array(
         'description' => t("Md5 hash of the file's contents when last parsed."),
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
     ),
     'primary key' => array('filename'),
@@ -1135,15 +1107,13 @@ function system_schema() {
         'description' => t("Primary key: A session ID. The value is generated by PHP's Session API."),
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'hostname' => array(
         'description' => t('The IP address that last used this session ID (sid).'),
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => t('The Unix timestamp when this session last requested a page. Old records are purged by PHP automatically.'),
@@ -1178,29 +1148,25 @@ function system_schema() {
         'description' => t('The path of the primary file for this item, relative to the Drupal root; e.g. modules/node/node.module.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'name' => array(
         'description' => t('The name of the item; e.g. node.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type' => array(
         'description' => t('The type of the item, either module, theme, or theme_engine.'),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'owner' => array(
         'description' => t("A theme's 'parent' . Can be either a theme or an engine."),
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'status' => array(
         'description' => t('Boolean indicating whether or not this item is enabled.'),
@@ -1260,22 +1226,19 @@ function system_schema() {
         'description' => t('The Drupal path this alias is for; e.g. node/12.'),
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'dst' => array(
         'description' => t('The alias for this path; e.g. title-of-the-story.'),
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'language' => array(
         'description' => t('The language this alias is for; if blank, the alias will be used for unknown languages. Each Drupal path can have an alias for each supported language.'),
         'type' => 'varchar',
         'length' => 12,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'unique keys' => array(
@@ -3097,6 +3060,324 @@ function system_update_7012() {
 }
 
 /**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function system_update_7013() {
+  $ret = array();
+
+  $schema['variable'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'value' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['actions'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'parameters' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['batch'] = array(
+    'fields' => array(
+      'token' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['blocked_ips'] = array(
+    'fields' => array(
+      'ip' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache'] = array(
+    'fields' => array(
+      'cid' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_form'] = $schema['cache'];
+  $schema['cache_page'] = $schema['cache'];
+  $schema['cache_menu'] = $schema['cache'];
+  $schema['cache_registry'] = $schema['cache'];
+
+  $schema['files'] = array(
+    'fields' => array(
+      'filename' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'filepath' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'filemime' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['flood'] = array(
+    'fields' => array(
+      'event' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['menu_router'] = array(
+    'fields' => array(
+      'path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'load_functions' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'to_arg_functions' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'access_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'page_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'tab_parent' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'tab_root' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title_arguments' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'block_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'position' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['menu_links'] = array(
+    'fields' => array(
+     'menu_name' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'link_path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'router_path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'link_title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['registry'] = array(
+    'fields' => array(
+      'name'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'type'   => array(
+        'type' => 'varchar',
+        'length' => 9,
+        'not null' => FALSE,
+      ),
+      'filename'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'suffix' => array(
+        'type' => 'varchar',
+        'length' => 68,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['registry_file'] = array(
+    'fields' => array(
+      'filename'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'md5'  => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['sessions'] = array(
+    'fields' => array(
+      'sid' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['system'] = array(
+    'fields' => array(
+      'filename' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'owner' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['url_alias'] = array(
+    'fields' => array(
+      'src' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'dst' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
  * @} End of "defgroup updates-6.x-to-7.x"
  * The next series of updates should start at 8000.
  */
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.638
diff -u -p -r1.638 system.module
--- modules/system/system.module	15 Nov 2008 08:23:07 -0000	1.638
+++ modules/system/system.module	15 Nov 2008 10:03:00 -0000
@@ -1526,7 +1526,7 @@ function system_actions_manage() {
   }
 
   $row = array();
-  $instances_present = db_fetch_object(db_query("SELECT aid FROM {actions} WHERE parameters <> ''"));
+  $instances_present = db_fetch_object(db_query("SELECT aid FROM {actions} WHERE parameters IS NOT NULL"));
   $header = array(
     array('data' => t('Action type'), 'field' => 'type'),
     array('data' => t('Description'), 'field' => 'description'),
Index: modules/update/update.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/update/update.install,v
retrieving revision 1.5
diff -u -p -r1.5 update.install
--- modules/update/update.install	6 Feb 2008 19:38:28 -0000	1.5
+++ modules/update/update.install	15 Nov 2008 10:03:00 -0000
@@ -62,3 +62,31 @@ function update_update_6000() {
   _update_remove_update_status_variables();
   return array();
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Update updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
+ */
+function update_update_7000() {
+  $ret = array();
+
+  $schema['cache_update'] = drupal_get_schema_unprocessed('system', 'cache');
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/user/user.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.install,v
retrieving revision 1.13
diff -u -p -r1.13 user.install
--- modules/user/user.install	20 Sep 2008 20:22:25 -0000	1.13
+++ modules/user/user.install	15 Nov 2008 10:03:00 -0000
@@ -23,15 +23,13 @@ function user_schema() {
       'authname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Unique authentication name.'),
       ),
       'module' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Module which is controlling the authentication.'),
       ),
     ),
@@ -53,8 +51,7 @@ function user_schema() {
       'permission' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('A single permission granted to the role identified by rid.'),
       ),
     ),
@@ -76,8 +73,7 @@ function user_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Unique role name.'),
       ),
     ),
@@ -99,36 +95,31 @@ function user_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 60,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Unique user name.'),
       ),
       'pass' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("User's password (hashed)."),
       ),
       'mail' => array(
         'type' => 'varchar',
         'length' => 64,
         'not null' => FALSE,
-        'default' => '',
         'description' => t("User's email address."),
       ),
       'theme' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("User's default theme."),
       ),
       'signature' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("User's signature."),
       ),
       'created' => array(
@@ -165,22 +156,19 @@ function user_schema() {
       'language' => array(
         'type' => 'varchar',
         'length' => 12,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("User's default language."),
       ),
       'picture' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("Path to the user's uploaded picture."),
       ),
       'init' => array(
         'type' => 'varchar',
         'length' => 64,
         'not null' => FALSE,
-        'default' => '',
         'description' => t('Email address used for initial account creation.'),
       ),
       'data' => array(
@@ -230,7 +218,7 @@ function user_schema() {
 }
 
 /**
- * @defgroup user-updates-6.x-to-7.x User updates from 6.x to 7.x
+ * @defgroup updates-6.x-to-7.x User updates from 6.x to 7.x
  * @{
  */
 
@@ -292,7 +280,102 @@ function user_update_7001() {
 }
 
 /**
- * @} End of "defgroup user-updates-6.x-to-7.x"
- * The next series of updates should start at 8000.
+ * Replace not null CHAR, VARCHAR or TEXT fields with default '' as nullable.
  */
+function user_update_7002() {
+  $ret = array();
+
+  $schema['authmap'] = array(
+    'fields' => array(
+      'authname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['role_permission'] = array(
+    'fields' => array(
+      'permission' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['role'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
 
+  $schema['users'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 60,
+        'not null' => FALSE,
+      ),
+      'pass' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'mail' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'theme' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'signature' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => FALSE,
+      ),
+      'picture' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'init' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */