Don't count NULL values in cardinalty for MyISAM tables.

Free row buffer cache after each query for MyISAM tables.
Added table join option FORCE INDEX
Fixed core dump bug when connecting with hostname that could not be resolved.


include/my_base.h:
  Don't count NULL values in cardinalty
myisam/mi_check.c:
  Don't count NULL values in cardinalty
myisam/mi_extra.c:
  Free row buffer cache after each query
myisam/mi_open.c:
  Avoid realloc if cache size doesn't change
myisam/mi_search.c:
  Don't count NULL values in cardinalty
myisam/myisamdef.h:
  Change buffer length from uint to uint32 to make it more portable/predictable
mysql-test/r/myisam.result:
  Test case for cardinality with NULL keys and FORCE INDEX
mysql-test/t/myisam.test:
  Test case for cardinality with NULL keys and FORCE INDEX
sql/lex.h:
  Added table join option FORCE INDEX
sql/mysql_priv.h:
  Added table join option FORCE INDEX
sql/opt_range.cc:
  Added table join option FORCE INDEX
sql/sql_base.cc:
  Added table join option FORCE INDEX
sql/sql_lex.h:
  Added table join option FORCE INDEX
sql/sql_parse.cc:
  Added table join option FORCE INDEX
  Don't use strlen() on hostname without first checking if it's not NULL
sql/sql_select.cc:
  Added table join option FORCE INDEX
sql/sql_yacc.yy:
  Added table join option FORCE INDEX
sql/table.h:
  Added table join option FORCE INDEX

1 files changed, 11 insertions, 3 deletions

diff --git a/myisam/mi_open.c b/myisam/mi_open.c
index aeacf81d90a..0da5ebabf40 100644
--- a/myisam/mi_open.c
+++ b/myisam/mi_open.c
@@ -559,28 +559,36 @@ err:
   DBUG_RETURN (NULL);
 } /* mi_open */
 
+
 byte *mi_alloc_rec_buff(MI_INFO *info, ulong length, byte **buf)
 {
   uint extra;
+  uint32 old_length;
+  LINT_INIT(old_length);
 
-  if (! *buf || length > mi_get_rec_buff_len(info, *buf))
+  if (! *buf || length > (old_length=mi_get_rec_buff_len(info, *buf)))
   {
     byte *newptr = *buf;
 
     /* to simplify initial init of info->rec_buf in mi_open and mi_extra */
     if (length == (ulong) -1)
+    {
       length= max(info->s->base.pack_reclength+info->s->base.pack_bits,
                   info->s->base.max_key_length);
+      /* Avoid unnecessary realloc */
+      if (newptr && length == old_length)
+	return newptr;
+    }
 
     extra= ((info->s->options & HA_OPTION_PACK_RECORD) ?
 	    ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER)+MI_SPLIT_LENGTH+
 	    MI_REC_BUFF_OFFSET : 0);
     if (extra && newptr)
-      newptr-=MI_REC_BUFF_OFFSET;
+      newptr-= MI_REC_BUFF_OFFSET;
     if (!(newptr=(byte*) my_realloc((gptr)newptr, length+extra+8,
                                      MYF(MY_ALLOW_ZERO_PTR))))
       return newptr;
-    *((uint *)newptr)=length;
+    *((uint32 *) newptr)= (uint32) length;
     *buf= newptr+(extra ?  MI_REC_BUFF_OFFSET : 0);
   }
   return *buf;