Inserting a negative value in the autoincrement column of a
partitioned innodb table was causing the value of the auto
increment counter to wrap around into a very large positive
value. The consequences are the same as if a very large positive
value was inserted into a column, e.g. reduced autoincrement
range, failure to read autoincrement counter.

The current patch ensures that before calculating the next
auto increment value, the current value is within the positive
maximum allowed limit.

mysql-test/suite/parts/inc/partition_auto_increment.inc:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Adds tests for performing insert,update and delete on a partition
  table with negative auto_increment values.
mysql-test/suite/parts/r/partition_auto_increment_innodb.result:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Result file for the innodb engine.
mysql-test/suite/parts/r/partition_auto_increment_memory.result:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Result file for the memory engine.
mysql-test/suite/parts/r/partition_auto_increment_myisam.result:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Result file for the myisam engine.
mysql-test/suite/parts/r/partition_auto_increment_ndb.result:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Result file for the ndb engine.
mysql-test/suite/parts/t/partition_auto_increment_archive.test:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Adds a variable that allows the Archive engine to skip tests
  that involve insertion of negative auto increment values.
mysql-test/suite/parts/t/partition_auto_increment_blackhole.test:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Adds a variable that allows the Blackhole engine to skip tests
  that involve insertion of negative auto increment values.
sql/ha_partition.cc:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Ensures that the current value is lesser than the upper limit
  for the type of the field before setting the next auto increment
  value to be calculated.
sql/ha_partition.h:
  Bug#45823 Assertion failure in file row/row0mysql.c line 1386
  
  Modifies the set_auto_increment_if_higher function, to take
  into account negative auto increment values when doing a
  comparison.