Merge mysql.com:/home/mydev/mysql-4.0-bug14400

into  mysql.com:/home/mydev/mysql-4.1-bug14400


myisam/mi_rkey.c:
  Bug#14400 - Query joins wrong rows from table which is subject of "concurrent insert"
  Manual merge
sql/sql_class.cc:
  Bug#14400 - Query joins wrong rows from table which is subject of "concurrent insert"
  Manual merge

myisam/mi_rkey.c

@@ -68,6 +68,7 @@ int mi_rkey(MI_INFO *info, byte *buf, int inx, const byte *key, uint key_len,
 
   if (fast_mi_readinfo(info))
     goto err;
+
   if (share->concurrent_insert)
     rw_rdlock(&share->key_root_lock[inx]);
 
@@ -91,14 +92,24 @@ int mi_rkey(MI_INFO *info, byte *buf, int inx, const byte *key, uint key_len,
     if (!_mi_search(info, keyinfo, key_buff, use_key_length,
                     myisam_read_vec[search_flag], info->s->state.key_root[inx]))
     {
-      while (info->lastpos >= info->state->data_file_length)
+      /*
+        If we are searching for an exact key (including the data pointer)
+        and this was added by an concurrent insert,
+        then the result is "key not found".
+      */
+      if ((search_flag == HA_READ_KEY_EXACT) &&
+          (info->lastpos >= info->state->data_file_length))
+      {
+        my_errno= HA_ERR_KEY_NOT_FOUND;
+        info->lastpos= HA_OFFSET_ERROR;
+      }
+      else while (info->lastpos >= info->state->data_file_length)
       {
         /*
 	  Skip rows that are inserted by other threads since we got a lock
 	  Note that this can only happen if we are not searching after an
 	  exact key, because the keys are sorted according to position
         */
-
         if  (_mi_search_next(info, keyinfo, info->lastkey,
                              info->lastkey_length,
                              myisam_readnext_vec[search_flag],
@@ -107,6 +118,7 @@ int mi_rkey(MI_INFO *info, byte *buf, int inx, const byte *key, uint key_len,
       }
     }
   }
+
   if (share->concurrent_insert)
     rw_unlock(&share->key_root_lock[inx]);
 

sql/sql_class.cc

@@ -821,7 +821,7 @@ bool select_send::send_data(List<Item> &items)
   Protocol *protocol= thd->protocol;
   char buff[MAX_FIELD_WIDTH];
   String buffer(buff, sizeof(buff), &my_charset_bin);
-  DBUG_ENTER("send_data");
+  DBUG_ENTER("select_send::send_data");
 
   protocol->prepare_for_resend();
   Item *item;
@@ -1032,7 +1032,7 @@ select_export::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
 bool select_export::send_data(List<Item> &items)
 {
 
-  DBUG_ENTER("send_data");
+  DBUG_ENTER("select_export::send_data");
   char buff[MAX_FIELD_WIDTH],null_buff[2],space[MAX_FIELD_WIDTH];
   bool space_inited=0;
   String tmp(buff,sizeof(buff),&my_charset_bin),*res;
@@ -1189,7 +1189,7 @@ bool select_dump::send_data(List<Item> &items)
   String tmp(buff,sizeof(buff),&my_charset_bin),*res;
   tmp.length(0);
   Item *item;
-  DBUG_ENTER("send_data");
+  DBUG_ENTER("select_dump::send_data");
 
   if (unit->offset_limit_cnt)
   {						// using limit offset,count