int nLeafEst;                   /* Space allocated for leaf blocks */
  int nWork;                      /* Number of leaf pages flushed */
  sqlite3_int64 iAbsLevel;        /* Absolute level of input segments */
  int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */
  sqlite3_int64 iStart;           /* Block number of first allocated block */
  sqlite3_int64 iEnd;             /* Block number of last allocated block */
  sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */

  NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];
};

/*
** An object of the following type is used to read data from a single
** FTS segment node. See the following functions:
**
................................................................................
  if( rc==SQLITE_OK ){
    rc = fts3WriteSegdir(p, 
        pWriter->iAbsLevel+1,               /* level */
        pWriter->iIdx,                      /* idx */
        pWriter->iStart,                    /* start_block */
        pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */
        pWriter->iEnd,                      /* end_block */
        pWriter->nLeafData,                 /* end_block */
        pRoot->block.a, pRoot->block.n      /* root */
    );
  }
  sqlite3_free(pRoot->block.a);
  sqlite3_free(pRoot->key.a);

  *pRc = rc;
................................................................................
    if( sqlite3_step(pSelect)==SQLITE_ROW ){
      iStart = sqlite3_column_int64(pSelect, 1);
      iLeafEnd = sqlite3_column_int64(pSelect, 2);
      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
      if( pWriter->nLeafData<0 ){
        pWriter->nLeafData = pWriter->nLeafData * -1;
      }

      nRoot = sqlite3_column_bytes(pSelect, 4);
      aRoot = sqlite3_column_blob(pSelect, 4);
    }else{
      return sqlite3_reset(pSelect);
    }

    /* Check for the zero-length marker in the %_segments table */
................................................................................
        }
      }

      if( nSeg!=0 ){
        pWriter->nLeafData = pWriter->nLeafData * -1;
      }
      fts3IncrmergeRelease(p, pWriter, &rc);
      if( nSeg==0 ){
        fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);
      }
    }

    sqlite3Fts3SegReaderFinish(pCsr);
  }

  int nLeafEst;                   /* Space allocated for leaf blocks */
  int nWork;                      /* Number of leaf pages flushed */
  sqlite3_int64 iAbsLevel;        /* Absolute level of input segments */
  int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */
  sqlite3_int64 iStart;           /* Block number of first allocated block */
  sqlite3_int64 iEnd;             /* Block number of last allocated block */
  sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */
  u8 bNoLeafData;                 /* If true, store 0 for segment size */
  NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];
};

/*
** An object of the following type is used to read data from a single
** FTS segment node. See the following functions:
**
................................................................................
  if( rc==SQLITE_OK ){
    rc = fts3WriteSegdir(p, 
        pWriter->iAbsLevel+1,               /* level */
        pWriter->iIdx,                      /* idx */
        pWriter->iStart,                    /* start_block */
        pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */
        pWriter->iEnd,                      /* end_block */
        (pWriter->bNoLeafData==0 ? pWriter->nLeafData : 0),   /* end_block */
        pRoot->block.a, pRoot->block.n      /* root */
    );
  }
  sqlite3_free(pRoot->block.a);
  sqlite3_free(pRoot->key.a);

  *pRc = rc;
................................................................................
    if( sqlite3_step(pSelect)==SQLITE_ROW ){
      iStart = sqlite3_column_int64(pSelect, 1);
      iLeafEnd = sqlite3_column_int64(pSelect, 2);
      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
      if( pWriter->nLeafData<0 ){
        pWriter->nLeafData = pWriter->nLeafData * -1;
      }
      pWriter->bNoLeafData = (pWriter->nLeafData==0);
      nRoot = sqlite3_column_bytes(pSelect, 4);
      aRoot = sqlite3_column_blob(pSelect, 4);
    }else{
      return sqlite3_reset(pSelect);
    }

    /* Check for the zero-length marker in the %_segments table */
................................................................................
        }
      }

      if( nSeg!=0 ){
        pWriter->nLeafData = pWriter->nLeafData * -1;
      }
      fts3IncrmergeRelease(p, pWriter, &rc);
      if( nSeg==0 && pWriter->bNoLeafData==0 ){
        fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);
      }
    }

    sqlite3Fts3SegReaderFinish(pCsr);
  }

do_execsql_test 6.5 {
  INSERT INTO x5 SELECT words FROM t1;
  SELECT level, idx, end_block FROM x5_segdir;
} {
  0 1 {1329 8297} 0 0 {1320 28009} 0 2 {1449 118006}
}

#do_test 3.2 {
  #t1_to_x2
  #execsql {SELECT level, count(*) FROM x2_segdir GROUP BY level}
#} {0 13 1 15 2 5}

#proc second {x} { lindex $x 1 }
#db func second second
#for {set i 0} {$i <1000} {incr i} {
#  t1_to_x2
#  db eval {
#    SELECT level, group_concat( second(end_block), ' ' ) AS c FROM x2_segdir GROUP BY level;



#  } {
#    puts "$i.$level: $c"
#  }







#}












































finish_test

do_execsql_test 6.5 {
  INSERT INTO x5 SELECT words FROM t1;
  SELECT level, idx, end_block FROM x5_segdir;
} {
  0 1 {1329 8297} 0 0 {1320 28009} 0 2 {1449 118006}
}

#--------------------------------------------------------------------------
# Ensure that if part of an incremental merge is performed by an old
# version that does not support storing segment sizes in the end_block
# field, no size is stored in the final segment (as it would be incorrect).
#
do_execsql_test 7.1 {
  CREATE VIRTUAL TABLE x6 USING fts4;
  INSERT INTO x6 SELECT words FROM t1;
  INSERT INTO x6 SELECT words FROM t1;
  INSERT INTO x6 SELECT words FROM t1;
  INSERT INTO x6 SELECT words FROM t1;
  INSERT INTO x6 SELECT words FROM t1;
  INSERT INTO x6 SELECT words FROM t1;
  SELECT level, idx, end_block FROM x6_segdir;
} {


  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
}

do_execsql_test 7.2 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 {16014 -51226}
}

do_execsql_test 7.3 {
  UPDATE x6_segdir SET end_block = first(end_block) WHERE level=1;
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 16014
}

do_execsql_test 7.4 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 16014
}

do_execsql_test 7.5 {
  INSERT INTO x6(x6) VALUES('merge=2500,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {598 118006} 0 1 {718 118006} 1 0 16014
}

do_execsql_test 7.6 {
  INSERT INTO x6(x6) VALUES('merge=2500,2');
  SELECT level, idx, start_block, leaves_end_block, end_block FROM x6_segdir;
} {
  2 0 23695 24147 {41262 633507}
}

do_execsql_test 7.7 {
  SELECT sum(length(block)) FROM x6_segments 
  WHERE blockid BETWEEN 23695 AND 24147
} {633507}



finish_test