mi_write: fix for ft2 when found word (in the tree) has different length as the word to insert

myisam/mi_check.c:
  one more correctness check for CHECK of fulltext indexes

myisam/mi_check.c

@@ -656,6 +656,14 @@ static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
         if (chk_index_down(param,info,&info->s->ft2_keyinfo,record,
                            temp_buff,&tmp_keys,key_checksum,1))
           goto err;
+        if (tmp_keys + subkeys)
+        {
+          mi_check_print_error(param,"Number of words in the 2nd level tree "
+                                  "does not match the number in the header. "
+                                  "Parent word in on the page %s, offset %d",
+                                  llstr(page,llbuff), old_keypos-buff);
+          goto err;
+        }
         (*keys)+=tmp_keys-1;
         continue;
       }

myisam/mi_write.c

@@ -372,6 +372,7 @@ static int w_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
         /* popular word. two-level tree. going down */
         my_off_t root=info->dupp_key_pos;
         keyinfo=&info->s->ft2_keyinfo;
+        get_key_full_length_rdonly(off, key);
         key+=off;
         keypos-=keyinfo->keylength+nod_flag; /* we'll modify key entry 'in vivo' */
         error=_mi_ck_real_write_btree(info, keyinfo, key, 0,