Very nasty bug.
It was caused by double free()-ing memory of join->select and 
join->quick. 

I was able to pinpoint it only after using Valgrind.

Plus better fix for bug with TMP_TABLE_PARAM.

Plus new constructor for SELECT_LEX.


mysql-test/r/innodb.result:
  Fix for a bug record #307.
  
  Very nasty bug.
  It was caused by double free()-ing memory of join->select and 
  join->quick. 
  
  I was able to pinpoint it only after using Valgrind.
mysql-test/t/innodb.test:
  Fix for a bug record #307.
  
  Very nasty bug.
  It was caused by double free()-ing memory of join->select and 
  join->quick. 
  
  I was able to pinpoint it only after using Valgrind.
sql/sql_lex.cc:
  Adding a usefull constructor
sql/sql_lex.h:
  Adding a usefull constructor which additionally required few more
  definitions.
sql/sql_select.cc:
  Fix for a bug record #307.
  
  Very nasty bug.
  It was caused by double free()-ing memory of join->select and 
  join->quick. 
  
  I was able to pinpoint it only after using Valgrind.
sql/sql_union.cc:
  Fixing bug #307.
  
  Also, a better fix for TMP_TABLE_PARAM bug.
  
  Also, use of the new constructor for SELECT_LEX.