revno: 3690.1.38

committer: Marc Alff <marc.alff@oracle.com>

branch nick: mysql-trunk-bug13819100

timestamp: Wed 2012-03-07 17:15:16 +0100

message:

  Bug#13819100 BROKEN SYNTAX ACCEPTED FOR START SLAVE, STOP SLAVE

  Before this fix, the parser accepted the following syntax for STOP SLAVE:

  STOP SLAVE ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ;

  The root cause was the bison grammar for rule slave_thread_opts,

  which produced a list of "SQL_THREAD", "RELAY_THREAD" or (empty string),

  separated by ",".

  The grammar has been fixed so that the grammar rule is:

  - either en empty string

  - or a list of "SQL_THREAD", "RELAY_THREAD" separated by ",".

  which is the proper syntax.

  In addition, the grammar rules have been cleaned up, so that, when practical:

  - (a) using the bison internal stack ($$, $1, etc) is preferred

  - (b) setting global variables in rules, as in Lex->slave_thd_opt= ...

    is avoided

  Bison is an ascendent parser, for which the natural pattern in (a).

  Pattern (b) is for descendent parsers, and mixing both concepts is a bad

  idea.

  Note that using the same option multiple times in the list is tolerated,

  as before, and interpreted as a single option (no change).