# 2019 May 16
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    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.
#
#***********************************************************************
#
#

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5corrupt4

# If SQLITE_ENABLE_FTS5 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}
sqlite3_fts5_may_be_corrupt 1

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE ttt USING fts5(a, b); 
  INSERT INTO ttt 
     VALUES('e ee eee e ee eee e ee eee', 'eee ee e e e ee eee ee ee');
  INSERT INTO ttt SELECT a||a, b||b FROM ttt;   
  INSERT INTO ttt SELECT a||a, b||b FROM ttt;   
}

expr srand(1)

proc mutate {blob i} {
  set o [expr {$i % [string length $blob]}]
  set a [string range $blob 0 $o-1]
  set b [string range $blob $o+1 end]
  set v [expr int(rand()*255) - 127]
  return "$a[binary format c $v]$b"
}
db func mutate mutate

for {set j 1000} {$j <= 5000} {incr j 1000} {
  do_test 1.$j {
    for {set i 0} {$i < 1000} {incr i} {
      execsql {
        BEGIN;
          UPDATE ttt_data SET block = mutate(block, $i) WHERE id>10;
      }
      foreach sql {
        {SELECT snippet(ttt, -1, '.', '..', '[', ']'), * FROM ttt('e*')}
        {SELECT snippet(ttt, -1, '.', '..', '[', ']'), * FROM ttt('e* NOT ee*')}
      } {
        catch { execsql $sql }
      }
      execsql ROLLBACK
    }
  } {}
}

sqlite3_fts5_may_be_corrupt 0
finish_test