- Duplicate parameters/variables, conditions and cursors (not allowed).
  - ITERATE in labelled BEGIN-END (not allowed).
  - Missing SQLSTATE [VALUE] keywords in CONDITION/HANDLER declaration (added).
  - Empty BEGIN-END (now allowed).
  - End label (now optional).


include/mysqld_error.h:
  New error code for duplicate things (vars et al) in SPs.
mysql-test/r/sp-error.result:
  New error tests for ITERATE in begin-end block and duplicate variables,
  conditions and cursors.
mysql-test/r/sp.result:
  New tests for empty begin-end blocks, overriding local variables outside scope
  only, leave a begin-end block, and SQLSTATE [VALUE] words for CONDITION/HANDLER
  declarations.
mysql-test/t/sp-error.test:
  New error tests for ITERATE in begin-end block and duplicate variables,
  conditions and cursors.
mysql-test/t/sp.test:
  New tests for empty begin-end blocks, overriding local variables outside scope
  only, leave a begin-end block, and SQLSTATE [VALUE] words for CONDITION/HANDLER
  declarations.
sql/lex.h:
  New SQLSTATE keyword.
sql/share/czech/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/danish/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/dutch/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/english/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/estonian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/french/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/german/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/greek/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/hungarian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/italian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/japanese/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/korean/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/norwegian-ny/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/norwegian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/polish/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/portuguese/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/romanian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/russian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/serbian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/slovak/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/spanish/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/swedish/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/share/ukrainian/errmsg.txt:
  New error message for duplicate things (vars et al) in SPs.
sql/sp_pcontext.cc:
  Keep track on scope limits for error checking of duplicate variables,
  conditions and cursors.
sql/sp_pcontext.h:
  Keep track on scope limits for error checking of duplicate variables,
  conditions and cursors.
  Also need to flag BEGIN labels to check for illegal ITERATEs.
sql/sql_yacc.yy:
  End-labels in SPs loop and begin-end blocks are now optional.
  SQLSTATE [VALUE] added to syntax for sqlstates.
  Check for duplicate variable, condition and cursor declarations, but
  only in the same scope.
  Empty BEGIN-END statements now allowed.
  Check if ITERATE is referring to a BEGIN label.