SQLite

    pReader->zTerm = zNew;
    pReader->nTermAlloc = nNew;
  }
  memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);
  pReader->nTerm = nPrefix+nSuffix;
  pNext += nSuffix;
  pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist);

  pReader->aDoclist = pNext;
  pReader->pOffsetList = 0;

  /* Check that the doclist does not appear to extend past the end of the
  ** b-tree node. And that the final byte of the doclist is either an 0x00 
  ** or 0x01. If either of these statements is untrue, then the data structure 
  ** is corrupt.
  */
  if( &pReader->aDoclist[pReader->nDoclist]>&pReader->aNode[pReader->nNode] 
   || (pReader->aDoclist[pReader->nDoclist-1]&0xFE)!=0
  ){
    return SQLITE_CORRUPT;
  }
  return SQLITE_OK;
}

/*
** Set the SegReader to point to the first docid in the doclist associated
** with the current term.
*/

# 2010 October 27
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# Test that the FTS3 extension does not crash when it encounters a
# corrupt data structure on disk.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS3 is not defined, omit this file.
ifcapable !fts3 { finish_test ; return }

set ::testprefix fts3corrupt

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts3;
  INSERT INTO t1 VALUES('hello');
} {}

do_test fts3corrupt-1.1 {
  set blob [db one {SELECT root from t1_segdir}]
  set blob [binary format a7ca* $blob 24 [string range $blob 8 end]]
  execsql { UPDATE t1_segdir SET root = $blob }
} {}

do_test fts3corrupt-1.2 {
  foreach w {a b c d e f g h i j k l m n o} {
    execsql { INSERT INTO t1 VALUES($w) }
  }
} {}

do_catchsql_test 1.3 {
  INSERT INTO t1 VALUES('world');
} {1 {database disk image is malformed}}

finish_test

do_execsql_test 1.1.1 {
  CREATE VIRTUAL TABLE t1 USING fts4;
}
do_execsql_test 1.1.2 "INSERT INTO t1 VALUES('[string repeat {a } 20000]')"
do_execsql_test 1.1.3 "INSERT INTO t1 VALUES('[string repeat {z } 20000]')"
do_execsql_test 1.1.4 {
  INSERT INTO t1 VALUES('a b c d e f a x y');
  INSERT INTO t1 VALUES('');
  INSERT INTO t1 VALUES('');
  INSERT INTO t1 VALUES('');
  INSERT INTO t1 VALUES('');
  INSERT INTO t1 VALUES('');
  INSERT INTO t1(t1) VALUES('optimize');



}
do_execsql_test 1.1.4 {
  SELECT count(*) FROM t1_segments WHERE length(block)>10000;

  UPDATE t1_segments SET block = zeroblob(length(block)) WHERE length(block)>10000;
} {2}

do_execsql_test 1.2.1 {
  SELECT content FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} {{a b c d e f a x y}}

do_execsql_test 1.2.2 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} [list                              \
   {a b c d [e] [f] [a] x y}         \
   {0 1 8 1 0 0 10 1 0 2 12 1}       \
   [list 3 1   1 1 1   1 8 8   1 8 8   8 5001 9]
]

do_execsql_test 1.2.3 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/3 a)';
} [list                                 \
   {[a] b c d [e] [f] [a] x y}          \
   {0 2 0 1 0 1 8 1 0 0 10 1 0 2 12 1}  \
   [list 3 1   1 1 1   1 8 8   2 8 8   8 5001 9]
]

do_execsql_test 1.3.1 { DROP TABLE t1 }

#-----------------------------------------------------------------------------
# Test cases fts3defer2-2.* focus specifically on the matchinfo function.
# 

do_execsql_test 2.3.1 {
  CREATE VIRTUAL TABLE t3 USING fts4;
  INSERT INTO t3 VALUES('a b c d e f');
  INSERT INTO t3 VALUES('x b c d e f');
  INSERT INTO t3 VALUES('d e f a b c');
  INSERT INTO t3 VALUES('b c d e f');
  INSERT INTO t3 VALUES('');
  INSERT INTO t3 VALUES('');
  INSERT INTO t3 VALUES('');
  INSERT INTO t3 VALUES('');
  INSERT INTO t3 VALUES('');
  INSERT INTO t3 VALUES('');
}
do_execsql_test 2.3.2 "
  INSERT INTO t3 VALUES('f e d c b [string repeat {a } 10000]')
"
foreach {tn sql} {
  1 {}
  2 { INSERT INTO t3(t3) VALUES('optimize') }
  3 { UPDATE t3_segments SET block = zeroblob(length(block)) 
      WHERE length(block)>10000;
  }
} {
  execsql $sql
  do_execsql_test 2.4.$tn {
    SELECT docid, mit(matchinfo(t3)) FROM t3 WHERE t3 MATCH '"a b c"';
  } {1 {1 1 1 4 4 11 912 6} 3 {1 1 1 4 4 11 912 6}}
}


finish_test