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.

5 files changed, 57 insertions, 16 deletions

diff --git a/myisam/mi_check.c b/myisam/mi_check.c
index 540f3c92ad3..b65e963bcb7 100644
--- a/myisam/mi_check.c
+++ b/myisam/mi_check.c
@@ -601,7 +601,8 @@ static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
       if (*keys != 1L)				/* not first_key */
       {
 	uint diff;
-	_mi_key_cmp(keyinfo->seg,info->lastkey,key,USE_WHOLE_KEY,SEARCH_FIND,
+	_mi_key_cmp(keyinfo->seg,info->lastkey,key,USE_WHOLE_KEY,
+		    SEARCH_FIND | SEARCH_NULL_ARE_NOT_EQUAL,
 		    &diff);
 	param->unique_count[diff-1]++;
       }
diff --git a/myisam/mi_extra.c b/myisam/mi_extra.c
index 8429b22dad4..75057dd4e6a 100644
--- a/myisam/mi_extra.c
+++ b/myisam/mi_extra.c
@@ -55,12 +55,17 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
     /*
       Free buffers and reset the following flags:
       EXTRA_CACHE, EXTRA_WRITE_CACHE, EXTRA_KEYREAD, EXTRA_QUICK
+
+      If the row buffer cache is large (for dynamic tables), reduce it
+      to save memory.
     */
     if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED))
     {
       info->opt_flag&= ~(READ_CACHE_USED | WRITE_CACHE_USED);
       error=end_io_cache(&info->rec_cache);
     }
+    if (share->base.blobs)
+      mi_alloc_rec_buff(info, -1, &info->rec_buff);
 #if defined(HAVE_MMAP) && defined(HAVE_MADVICE)
     if (info->opt_flag & MEMMAP_USED)
       madvise(share->file_map,share->state.state.data_file_length,MADV_RANDOM);
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;
diff --git a/myisam/mi_search.c b/myisam/mi_search.c
index d57fd1bb5b2..41d53e76241 100644
--- a/myisam/mi_search.c
+++ b/myisam/mi_search.c
@@ -260,9 +260,11 @@ int _mi_prefix_search(MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *page,
                       uchar *key, uint key_len, uint nextflag, uchar **ret_pos,
                       uchar *buff, my_bool *last_key)
 {
-  /* my_flag is raw comparison result to be changed according to
-     SEARCH_NO_FIND,SEARCH_LAST and HA_REVERSE_SORT flags.
-     flag is the value returned by _mi_key_cmp and as treated as final */
+  /*
+    my_flag is raw comparison result to be changed according to
+    SEARCH_NO_FIND,SEARCH_LAST and HA_REVERSE_SORT flags.
+    flag is the value returned by _mi_key_cmp and as treated as final
+  */
   int flag=0, my_flag=-1;
   uint nod_flag, length, len, matched, cmplen, kseg_len;
   uint prefix_len,suffix_len;
@@ -695,13 +697,29 @@ static int compare_bin(uchar *a, uint a_length, uchar *b, uint b_length,
 }
 
 
-        /*
-        ** Compare two keys
-        ** Returns <0, 0, >0 acording to which is bigger
-        ** Key_length specifies length of key to use.  Number-keys can't
-        ** be splited
-        ** If flag <> SEARCH_FIND compare also position
-        */
+/*
+  Compare two keys
+
+  SYNOPSIS
+    _mi_key_cmp()
+    keyseg	Key segments of key to compare
+    a		First key to compare, in format from _mi_pack_key()
+		This is normally key specified by user
+    b		Second key to compare.  This is always from a row
+    key_length	Length of key to compare.  This can be shorter than
+		a to just compare sub keys
+    next_flag	How keys should be compared
+		If bit SEARCH_FIND is not set the keys includes the row
+		position and this should also be compared
+
+  NOTES
+    Number-keys can't be splited
+  
+  RETURN VALUES
+    <0	If a < b
+    0	If a == b
+    >0	If a > b
+*/
 
 #define FCMP(A,B) ((int) (A) - (int) (B))
 
@@ -738,6 +756,15 @@ int _mi_key_cmp(register MI_KEYSEG *keyseg, register uchar *a,
       {
         if (nextflag == (SEARCH_FIND | SEARCH_UPDATE))
           nextflag=SEARCH_SAME;                 /* Allow duplicate keys */
+	else if (nextflag & SEARCH_NULL_ARE_NOT_EQUAL)
+	{
+	  /*
+	    This is only used from mi_check() to calculate cardinality.
+	    It can't be used when searching for a key as this would cause
+	    compare of (a,b) and (b,a) to return the same value.
+	  */
+	  return -1;
+	}
         next_key_length=key_length;
         continue;                               /* To next key part */
       }
diff --git a/myisam/myisamdef.h b/myisam/myisamdef.h
index 07744e11e5f..601a9a40aea 100644
--- a/myisam/myisamdef.h
+++ b/myisam/myisamdef.h
@@ -358,7 +358,7 @@ struct st_myisam_info {
 #define MI_DYN_ALIGN_SIZE	4	/* Align blocks on this */
 #define MI_MAX_DYN_HEADER_BYTE	13	/* max header byte for dynamic rows */
 #define MI_MAX_BLOCK_LENGTH	((((ulong) 1 << 24)-1) & (~ (ulong) (MI_DYN_ALIGN_SIZE-1)))
-#define MI_REC_BUFF_OFFSET      ALIGN_SIZE(MI_DYN_DELETE_BLOCK_HEADER+sizeof(uint))
+#define MI_REC_BUFF_OFFSET      ALIGN_SIZE(MI_DYN_DELETE_BLOCK_HEADER+sizeof(uint32))
 
 #define MEMMAP_EXTRA_MARGIN	7	/* Write this as a suffix for file */
 
@@ -529,7 +529,7 @@ extern byte *mi_alloc_rec_buff(MI_INFO *,ulong, byte**);
         ((((info)->s->options & HA_OPTION_PACK_RECORD) && (buf)) ? \
         (buf) - MI_REC_BUFF_OFFSET : (buf))
 #define mi_get_rec_buff_len(info,buf)                              \
-        (*((uint *)(mi_get_rec_buff_ptr(info,buf))))
+        (*((uint32 *)(mi_get_rec_buff_ptr(info,buf))))
 
 extern ulong _mi_rec_unpack(MI_INFO *info,byte *to,byte *from,
 			    ulong reclength);