Fix for bug #13025; Server crash in filesort because wrong call to handler::position()

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-4.1

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-4.1

into moonbone.local:/work/12695-bug-4.1-mysql

  Customer's test case for bug#12695 Item_func_isnull::update_used_tables() did 
  not update const_item_cache.

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-4.1

into  mysql.com:/home/alexi/dev/mysql-4.1-12101

Added test case.

into  c-4a09e253.1238-1-64736c10.cust.bredbandsbolaget.se:/home/pappa/bug12594

   This fix is cancellation of ChangeSet
   1.2329 05/07/12 08:35:30 reggie@linux.site +8 -0
   Bug 7142  Show Fields from fails using Borland's dbExpress interface
   The reason is we can't fix bug#7142 without
   breaking of existing applications/APIs that worked fine with earlier 4.1
   bug 7142 is fixed in 5.0

into  c-4a09e253.1238-1-64736c10.cust.bredbandsbolaget.se:/home/pappa/bug12594

into serg.mylan:/usr/home/serg/Abk/mysql-4.1

into serg.mylan:/usr/home/serg/Abk/mysql-4.1

into rurik.mysql.com:/home/igor/dev/mysql-4.1-0

  Fixed bug #12885.
  Forced inheritence of the maybe_null flag for the expressions
  containing GROUP BY attributes in selects with ROLLUP.
olap.test, olap.result:
  Added test case for bug #12885.

  fixed compile error

into  mysql.com:/Users/mikron/mysql-4.1

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

so that _only_ backup master replies to API
 

into mysql.com:/M41/mysql-4.1

Added debug info to all log page headers

into  selena.:H:/MYSQL/src/#12517-mysql-4.1

into  mysql.com:/home/stewart/Documents/MySQL/4.1/bug11607

into rurik.mysql.com:/home/igor/dev/mysql-4.1-0

into  mysql.com:/home/hartmut/projects/mysql/dev/4.1

into  mysql.com:/home/alexi/mysql-4.1

Small tweak for random read performance (we shouldn't always tell the OS that we will be doing a linear scan). 

into  mysql.com:/home/alexi/dev/mysql-4.1-0

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

into  mysql.com:/usr/home/bar/mysql-4.1.b12611