First part of automatic repair of MyISAM tables.

Error on full disk on repair.
SIGHUP signal handling.
Update with keys on timestamp
Portability fixes


Docs/manual.texi:
  Added documentation about automatic repair of MyISAM tables
client/mysql.cc:
  Remove usage of tempnam.
include/my_sys.h:
  Added create_temp_file
include/myisam.h:
  Fix for disk full on repair
myisam/mi_check.c:
  Fix for disk full on repair
myisam/sort.c:
  Fix for disk full on repair & removed usage of tempnam()
mysys/mf_cache.c:
  Remove usage of tempnam()
mysys/mf_dirname.c:
  Changed convert_dirname to return end 0
mysys/my_fopen.c:
  Security fixes
mysys/my_tempnam.c:
  remove blanks
readline/bind.c:
  Portability fixes
readline/complete.c:
  Portability fixes
readline/histexpand.c:
  Portability fixes
readline/input.c:
  Portability fixes
readline/search.c:
  Portability fixes
readline/shell.c:
  Portability fixes
readline/terminal.c:
  Portability fixes
readline/tilde.c:
  Portability fixes
readline/undo.c:
  Portability fixes
regex/cname.h:
  Portability fixes
regex/debug.c:
  Portability fixes
regex/main.c:
  Portability fixes
regex/regcomp.c:
  Portability fixes
regex/regerror.c:
  Portability fixes
sql/filesort.cc:
  Remove dummy code
sql/ha_myisam.cc:
  Automatic repair of MyISAM tables
sql/ha_myisam.h:
  Automatic repair of MyISAM tables
sql/handler.cc:
  Automatic repair of MyISAM tables
sql/handler.h:
  Automatic repair of MyISAM tables
sql/key.cc:
  Fix for UPDATE with key on timestamp column
sql/mysql_priv.h:
  Automatic repair of MyISAM tables
sql/mysqld.cc:
  Automatic repair of MyISAM tables & signal SIGHUP handling
sql/sql_base.cc:
  Automatic repair of MyISAM tables
sql/sql_class.cc:
  Automatic repair of MyISAM tables
sql/sql_class.h:
  Fix for insert with reference to columns
sql/sql_insert.cc:
  Fix for insert with reference to columns
sql/table.cc:
  Automatic repair of MyISAM tables
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted

sql/sql_class.cc

@@ -88,6 +88,7 @@ THD::THD()
   open_tables=temporary_tables=0;
   tmp_table=0;
   lock=locked_tables=0;
+  used_tables=0;
   cuted_fields=0L;
   options=thd_startup_options;
   update_lock_default= low_priority_updates ? TL_WRITE_LOW_PRIORITY : TL_WRITE;