p->rc = FTS5_CORRUPT;
    }else{
      const u8 *a = &pIter->pLeaf->p[iOff];
      pIter->iLeafOffset += fts5GetPoslistSize(a, &pIter->nPos, &pIter->bDel);
    }
  }
}


















/*
** Fts5SegIter.iLeafOffset currently points to the first byte of the 
** "nSuffix" field of a term. Function parameter nKeep contains the value
** of the "nPrefix" field (if there was one - it is passed 0 if this is
** the first term in the segment).
**
................................................................................

  iOff += fts5GetVarint32(&a[iOff], nNew);
  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;
  pIter->iTermLeafPgno = pIter->iLeafPgno;
  if( iOff>=pIter->pLeaf->n ){
    fts5SegIterNextPage(p, pIter);
    if( pIter->pLeaf==0 ){
      if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
      return;
    }
    iOff = 4;
    a = pIter->pLeaf->p;
  }
  iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
  pIter->iLeafOffset = iOff;

}

/*
** Initialize the iterator object pIter to iterate through the entries in
** segment pSeg. The iterator is left pointing to the first entry when 
** this function returns.
**
................................................................................
    *pbDlidx = 0;
    pPtr += nNew;
  }

  fts5AssertNodeSeekOk(pNode, pTerm, nTerm, iPg, *pbDlidx);
  return iPg;
}




























































































































/*
** Initialize the object pIter to point to term pTerm/nTerm within segment
** pSeg. If there is no such term in the index, the iterator is set to EOF.
**
** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
** an error has already occurred when this function is called, it is a no-op.
................................................................................
    iPg = pSeg->pgnoFirst;
    bDlidx = 0;
  }

  pIter->iLeafPgno = iPg - 1;
  fts5SegIterNextPage(p, pIter);

  if( (pLeaf = pIter->pLeaf) ){
    int res;
    pIter->iLeafOffset = fts5GetU16(&pLeaf->p[2]);
    if( pIter->iLeafOffset<4 || pIter->iLeafOffset>=pLeaf->n ){
      p->rc = FTS5_CORRUPT;
    }else{
      fts5SegIterLoadTerm(p, pIter, 0);
      fts5SegIterLoadNPos(p, pIter);
      do {
        res = fts5BufferCompareBlob(&pIter->term, pTerm, nTerm);
        if( res>=0 ) break;
        fts5SegIterNext(p, pIter, 0);
      }while( pIter->pLeaf && p->rc==SQLITE_OK );

      if( bGe==0 && res ){
        /* Set iterator to point to EOF */
        fts5DataRelease(pIter->pLeaf);
        pIter->pLeaf = 0;
      }
    }

  }

  if( p->rc==SQLITE_OK && bGe==0 ){
    pIter->flags |= FTS5_SEGITER_ONETERM;
    if( pIter->pLeaf ){
      if( flags & FTS5INDEX_QUERY_DESC ){
        pIter->flags |= FTS5_SEGITER_REVERSE;

      p->rc = FTS5_CORRUPT;
    }else{
      const u8 *a = &pIter->pLeaf->p[iOff];
      pIter->iLeafOffset += fts5GetPoslistSize(a, &pIter->nPos, &pIter->bDel);
    }
  }
}

static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  int iOff = pIter->iLeafOffset;

  if( iOff>=pIter->pLeaf->n ){
    fts5SegIterNextPage(p, pIter);
    if( pIter->pLeaf==0 ){
      if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
      return;
    }
    iOff = 4;
    a = pIter->pLeaf->p;
  }
  iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
  pIter->iLeafOffset = iOff;
}

/*
** Fts5SegIter.iLeafOffset currently points to the first byte of the 
** "nSuffix" field of a term. Function parameter nKeep contains the value
** of the "nPrefix" field (if there was one - it is passed 0 if this is
** the first term in the segment).
**
................................................................................

  iOff += fts5GetVarint32(&a[iOff], nNew);
  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;
  pIter->iTermLeafPgno = pIter->iLeafPgno;
  pIter->iLeafOffset = iOff;










  fts5SegIterLoadRowid(p, pIter);
}

/*
** Initialize the iterator object pIter to iterate through the entries in
** segment pSeg. The iterator is left pointing to the first entry when 
** this function returns.
**
................................................................................
    *pbDlidx = 0;
    pPtr += nNew;
  }

  fts5AssertNodeSeekOk(pNode, pTerm, nTerm, iPg, *pbDlidx);
  return iPg;
}

/*
** The iterator object passed as the second argument currently contains
** no valid values except for the Fts5SegIter.pLeaf member variable. This
** function searches the leaf page for a term matching (pTerm/nTerm).
**
*/
static void fts5LeafSeek(
  Fts5Index *p,                   /* Leave any error code here */
  int bGe,                        /* True for a >= search */
  Fts5SegIter *pIter,             /* Iterator to seek */
  const u8 *pTerm, int nTerm      /* Term to search for */
){
  int iOff;
  const u8 *a = pIter->pLeaf->p;
  int n = pIter->pLeaf->n;

  int nMatch = 0;
  int nKeep = 0;
  int nNew = 0;

  assert( p->rc==SQLITE_OK );
  assert( pIter->pLeaf );

  iOff = fts5GetU16(&a[2]);
  if( iOff<4 || iOff>=n ){
    p->rc = FTS5_CORRUPT;
    return;
  }

  while( 1 ){
    int i;
    int nCmp;
    i64 rowid;

    /* Figure out how many new bytes are in this term */

    nNew = a[iOff++];
    if( nNew & 0x80 ){ 
      iOff--;
      iOff += fts5GetVarint32(&a[iOff], nNew);
    }

    if( nKeep<nMatch ){
      goto search_failed;
    }

    assert( nKeep>=nMatch );
    if( nKeep==nMatch ){
      nCmp = MIN(nNew, nTerm-nMatch);
      for(i=0; i<nCmp; i++){
        if( a[iOff+i]!=pTerm[nMatch+i] ) break;
      }
      nMatch += i;

      if( nTerm==nMatch ){
        if( i==nNew ){
          goto search_success;
        }else{
          goto search_failed;
        }
      }else if( i<nNew && a[iOff+i]>pTerm[nMatch] ){
        goto search_failed;
      }
    }
    iOff += nNew;

    /* Skip past the doclist. If the end of the page is reached, bail out. */
    iOff += fts5GetVarint(&a[iOff], &rowid);
    while( iOff<n ){
      int nPos;

      iOff += fts5GetVarint32(&a[iOff], nPos);
      iOff += (nPos / 2);

      /* Skip past docid delta */
      iOff += fts5GetVarint(&a[iOff], &rowid);
      if( rowid==0 ) break;
    };
    if( iOff>=n ) goto search_failed;

    /* Read the nKeep field of the next term. */
    nKeep = a[iOff++];
    if( nKeep & 0x80 ){
      iOff--;
      iOff += fts5GetVarint32(&a[iOff], nKeep);
    }
  }

 search_failed:
  if( bGe==0 ){
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = 0;
    return;
  }else if( iOff>=n ){
    do {
      fts5SegIterNextPage(p, pIter);
      if( pIter->pLeaf==0 ) return;
      a = pIter->pLeaf->p;
      iOff = fts5GetU16(&a[2]);
      if( iOff ){
        if( iOff<4 || iOff>=n ){
          p->rc = FTS5_CORRUPT;
        }else{
          nKeep = 0;
          iOff += fts5GetVarint32(&a[iOff], nNew);
          break;
        }
      }
    }while( 1 );
  }

 search_success:
  pIter->iLeafOffset = iOff + nNew;
  pIter->iTermLeafOffset = pIter->iLeafOffset;
  pIter->iTermLeafPgno = pIter->iLeafPgno;

  fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);

  fts5SegIterLoadRowid(p, pIter);
  fts5SegIterLoadNPos(p, pIter);
}

/*
** Initialize the object pIter to point to term pTerm/nTerm within segment
** pSeg. If there is no such term in the index, the iterator is set to EOF.
**
** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
** an error has already occurred when this function is called, it is a no-op.
................................................................................
    iPg = pSeg->pgnoFirst;
    bDlidx = 0;
  }

  pIter->iLeafPgno = iPg - 1;
  fts5SegIterNextPage(p, pIter);


















  if( pIter->pLeaf ){


    fts5LeafSeek(p, bGe, pIter, pTerm, nTerm);
  }

  if( p->rc==SQLITE_OK && bGe==0 ){
    pIter->flags |= FTS5_SEGITER_ONETERM;
    if( pIter->pLeaf ){
      if( flags & FTS5INDEX_QUERY_DESC ){
        pIter->flags |= FTS5_SEGITER_REVERSE;

}
do_execsql_test 2.1 {
  INSERT INTO t1 VALUES('a b c', 'd e f');
}
do_test 2.2 {
  execsql { SELECT fts5_decode(id, block) FROM t1_data WHERE id==10 }
} {/{\(structure\) {lvl=0 nMerge=0 {id=[0123456789]* h=1 leaves=1..1}}}/}










do_execsql_test 2.3 {
  INSERT INTO t1(t1) VALUES('integrity-check');
}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 3.0 {
................................................................................
      set z [doc]
      set rowid [expr int(rand() * 100)]
      execsql { REPLACE INTO t1(rowid,x,y,z) VALUES($rowid, $x, $y, $z) }
    }
    execsql { INSERT INTO t1(t1) VALUES('integrity-check'); }
  } {}
}
#db eval {SELECT rowid, fts5_decode(rowid, block) aS r FROM t1_data} {puts $r}
#exit

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 8.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, prefix="1,2,3");
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);

}
do_execsql_test 2.1 {
  INSERT INTO t1 VALUES('a b c', 'd e f');
}
do_test 2.2 {
  execsql { SELECT fts5_decode(id, block) FROM t1_data WHERE id==10 }
} {/{\(structure\) {lvl=0 nMerge=0 {id=[0123456789]* h=1 leaves=1..1}}}/}

foreach w {a b c d e f} {
  do_execsql_test 2.3.$w.asc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w;
  } {1}
  do_execsql_test 2.3.$w.desc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w ORDER BY rowid DESC;
  } {1}
}

do_execsql_test 2.4 {
  INSERT INTO t1(t1) VALUES('integrity-check');
}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 3.0 {
................................................................................
      set z [doc]
      set rowid [expr int(rand() * 100)]
      execsql { REPLACE INTO t1(rowid,x,y,z) VALUES($rowid, $x, $y, $z) }
    }
    execsql { INSERT INTO t1(t1) VALUES('integrity-check'); }
  } {}
}



#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 8.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, prefix="1,2,3");
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);

  do_test $tn2.1.1 {
    foreach {id x y} $data {
      execsql { INSERT INTO xx(rowid, x, y) VALUES($id, $x, $y) }
    }
    execsql { INSERT INTO xx(xx) VALUES('integrity-check') }
  } {}


  #-------------------------------------------------------------------------
  # Test phrase queries.
  #
  foreach {tn phrase} {
    1 "o"
    2 "b q"

  do_test $tn2.1.1 {
    foreach {id x y} $data {
      execsql { INSERT INTO xx(rowid, x, y) VALUES($id, $x, $y) }
    }
    execsql { INSERT INTO xx(xx) VALUES('integrity-check') }
  } {}


  #-------------------------------------------------------------------------
  # Test phrase queries.
  #
  foreach {tn phrase} {
    1 "o"
    2 "b q"

          break
        }
      }
      if {$bMatch} { lappend ret $rowid }
    }
    return $ret
  }
  

  foreach {bAsc sql} {
    0 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix ORDER BY rowid DESC}
    1 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix}
  } {
    foreach {tn prefix} {
      1  {a*} 2 {ab*} 3 {abc*} 4 {abcd*} 5 {abcde*} 
      6  {f*} 7 {fg*} 8 {fgh*} 9 {fghi*} 10 {fghij*}
      11 {k*} 12 {kl*} 13 {klm*} 14 {klmn*} 15 {klmno*}
      16 {p*} 17 {pq*} 18 {pqr*} 19 {pqrs*} 20 {pqrst*}
      21 {u*} 22 {uv*} 23 {uvw*} 24 {uvwx*} 25 {uvwxy*} 26 {uvwxyz*}

          break
        }
      }
      if {$bMatch} { lappend ret $rowid }
    }
    return $ret
  }

  
  foreach {bAsc sql} {
    1 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix}
    0 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix ORDER BY rowid DESC}
  } {
    foreach {tn prefix} {
      1  {a*} 2 {ab*} 3 {abc*} 4 {abcd*} 5 {abcde*} 
      6  {f*} 7 {fg*} 8 {fgh*} 9 {fghi*} 10 {fghij*}
      11 {k*} 12 {kl*} 13 {klm*} 14 {klmn*} 15 {klmno*}
      16 {p*} 17 {pq*} 18 {pqr*} 19 {pqrs*} 20 {pqrst*}
      21 {u*} 22 {uv*} 23 {uvw*} 24 {uvwx*} 25 {uvwxy*} 26 {uvwxyz*}

} {-56 -22 -11}

do_execsql_test 2.3 {
  ROLLBACK;
  SELECT rowid FROM yy WHERE yy MATCH 'a + b + c';
} {-56 -22}



















finish_test

} {-56 -22 -11}

do_execsql_test 2.3 {
  ROLLBACK;
  SELECT rowid FROM yy WHERE yy MATCH 'a + b + c';
} {-56 -22}

#-------------------------------------------------------------------------

do_execsql_test 3.1 {
  CREATE VIRTUAL TABLE abc USING fts5(a);
  INSERT INTO abc(rowid, a) VALUES(1, 'a');
  BEGIN;
    INSERT INTO abc(rowid, a) VALUES(2, 'a');
}
breakpoint
do_execsql_test 3.2 {
    SELECT rowid FROM abc WHERE abc MATCH 'a';
} {1 2}

do_execsql_test 3.3 {
  COMMIT;
  SELECT rowid FROM abc WHERE abc MATCH 'a';
} {1 2}

finish_test