- Modified patch #18328 by Neil: currently the two forum topic blocks share a number of topics in block setting. This is a bit confusing since configuring one blockshould not affect another block.  Fixed some indentation as well.

   1. Removed a duplicate line from the changes to update.inc.
   2. Excluded the session.inc changes: they did not make sense to me.
   3. Excluded the search related changes in the node and search module. According to Steven these are not correct.

- The update for the twin comments was 'borken' and had several bugs.

- Patch #17747 by Adrian: first round of PostgreSQL updates!

- Patch #10425 by ccourtne and walkah: added admin screens to maintain forums instead of forcing the user to add a taxonomy.

- Patch #16074 by Andre Molnar: add configuration option to show blocks only on pages of certain node type.

  Modified the patch to remove some redundant code, to translate strings, and to better use the menu system.

- Patch #15962 by Goba: no need to drop the accesslog table to add a new primary key.

- Patch #6847 by Gerhard: replaced vocabulary->nodes by a separate table and tidied up the taxonomy API a bit.  This fixes a number of issues.

  We added a 'severity' column to watchdog():
    watchdog($type, $message, $link) --> watchdog($type, $message, $severity, $link);

    * Specify a severity in case you are reporting a warning or error.
    * The $link-parameter is now the fourth parameter instead of the third.

  TODO: document this in the upgrade guide.

- Refactored the queue module: removed the queue module's field from the node table.  With help from Gerhard.

- Slight addition to INSTALL.txt with regard to PHP versions.

- Updated/reworded some node type descriptions as per Boris' suggestions.

- Adding missing {} around a table name in update.php.

- Changed aid from tinyint to int.

  changes are:

  1. Simplified the statistics pages: there are less pages and on the
     remaining pages there is a lot less visual clutter (less columns and
     better presentation).

  2. Reorganized the 'administer - logs' menu: flattened the menu structure
     and removed a number of links.

  3. Improved performance.  Most statistics pages used about 160 slow SQL
     queries which made the statistics pages fairly unusable on my system.
     The new pages use at least 10 times less SQL queries and render much
     faster.  They are actually usable.

  4. There is now a 'track'-tab on node pages, and a second subtrab on the
     user accounts 'track'-tab for people with the 'access statistics'
     permission.  They can be used to resp. track the node and the user.
     This makes the statistics more accessible.

  5. Changed the way watchdog messages are filtered.  This makes it easier
     to introduce new watchdog types.

  6. Reworked the statistics module's permissions.

  7. Less code: 223 insertions(+), 343 deletions(-).

  8. Fixed several glitches: for example, the statistics pages sorted the
     'Name' column by user ID instead of by name.  Unfortunately, it is
     too difficult to backport these to DRUPAL-4-5.

  TODO:

  1. Review the statistics modules help pages.

  2. Help fine-tune the interfaces/views.

  NOTES:

  1. You'll want to run update.php.

    + added support for multi-site configurations.
    + tidied up some old cruft and added code comments.

- Adding the missing flood tables.  Sorry.

- Performance improvement: made 'sid' the primary key of the sessions table.
  That should improve performance of session handling as well improve
  performance of the "Who's online"-block.  Drupal.org's sessions table
  contains appr. 40.000 sessions on a slow day and rendering the "Who's
  online"-block became a performance bottleneck.

  This change has yet to be tested on a busy site so things might go wrong.

   + When a comment is posted, a node needs to be re-indexed. Luckily, we can use node_comment_statistics for this easily.
   + When a node is deleted, it should be deleted from the search index as well.
   + The search wipe didn't properly remove links to nodes from the index.
   + Section url was faulty in _help.
   + Minor code rearrangement.

   + Display 'friendly' name rather than module name in search watchdog
     messages.
   + Remove left-over from search_total table.
   + Add index wipe button to the admin
   + Moved the admin to admin/settings/search
   + Prevented menu bug when node modules update the breadcrumb in view
     (thanks JonBob).
   + Changed search_total table's word key to PRIMARY.

The primary goal of this patch is to take the 'custom' and 'path' columns of the block overview page and make them into something understandable. As of Drupal 4.5 'custom' lacked an explanation which wasn't buried in help text and path required dealing with regular expressions.

Every block now has a configuration page to control these options. This gives more space to make form controls which do not require a lengthy explanation. This page also gives modules a chance to put their block configuration options in a place that makes sense using new operations in the block hook.

The only required changes to modules implementing hook_block() is to be careful about what is returned. Do not return anything if $op is not 'list' or 'view'. Once this change is made, modules will still be compatible with Drupal 4.5. Required changes to core modules are included in this path.

An additional optional change to modules is to implement the additional $op options added. 'configure' should return a string containing the configuration form for the block with the appropriate $delta. 'configure save' will come with an additional $edit argument, which will contain the submitted form data for saving. These changes to core modules are also included in this patch.

1) Clean up the text analyser: make it handle UTF-8 and all sorts of characters. The word splitter now does intelligent splitting into words and supports all Unicode characters. It has smart handling of acronyms, URLs, dates, ...

2) It now indexes the filtered output, which means it can take advantage of HTML tags. Meaningful tags (headers, strong, em, ...) are analysed and used to boost certain words scores. This has the side-effect of allowing the indexing of PHP nodes.

3) Link analyser for node links. The HTML analyser also checks for links. If they point to a node on the current site (handles path aliases) then the link's words are counted as part of the target node. This helps bring out commonly linked FAQs and answers to the top of the results.

4) Index comments along with the node. This means that the search can make a difference between a single node/comment about 'X' and a whole thread about 'X'. It also makes the search results much shorter and more relevant (before this patch, comments were even shown first).

5) We now keep track of total counts as well as a per item count for a word. This allows us to divide the word score by the total before adding up the scores for different words, and automatically makes noisewords have less influence than rare words. This dramatically improves the relevancy of multiword searches. This also makes the disadvantage of now using OR searching instead of AND searching less problematic.

6) Includes support for text preprocessors through a hook. This is required to index Chinese and Japanese, because these languages do not use spaces between words. An external utility can be used to split these into words through a simple wrapper module. Other uses could be spell checking (although it would have no UI).

7) Indexing is now regulated: only a certain amount of items will be indexed per cron run. This prevents PHP from running out of memory or timing out. This also makes the reindexing required for this patch automatic. I also added an index coverage estimate to the search admin screen.

8) Code cleanup! Moved all the search stuff from common.inc into search.module, rewired some hooks and simplified the functions used. The search form and results now also use valid XHTML and form_ functions. The search admin was moved from search/configure to admin/search for consistency.

9) Improved search output: we also show much more info per item: date, author, node type, amount of comments and a cool dynamic excerpt à la Google. The search form is now much more simpler and the help is only displayed as tips when no search results are found.

10) By moving all search logic to SQL, I was able to add a pager to the search results. This improves usability and performance dramatically.

- Patch #11728 by Uwe Hermann: fixed some typos in the code comments, Doxygen documentation and screen output.

  Uwe: I dropped the 'iff' chunks as 'iff' stands for 'if and only if'.

  + Drupal 4.4 stored profile data in the serialized user->data column. Drupal 4.5 stores profile data in tables (but user->data is still available and used for other stuff, like locale or themes).  The update from 4.4 to 4.5 didn't remove the old data from the user->data column properly, because there is no mechanism in user_save to do so (it did try to unset the fields, but this has no effect).

  + On registration, hook_user('insert') is invoked after saving the data column. This means that any module-specific data is put into the data field. We cannot move hook_user('insert') higher up, because before that point, we do not have a complete $user object yet.

Bug: the default filter setup had the wrong filter delta for the linebreak filter. Now it matches updates.inc.