Function uses a variable only available under debug mode.

DBUG_EXECUTE_IF macro. The usage of the former caused breakage in other
trees as it got removed from the dbug library.

mysql-test-run.pl --start-and-exit starts but does not exit
Instead, it hangs with ActiveState perl. The error is
believed to be a bug in ActiveState implementation.
Workaround is using POSIX::_exit, as described here
http://www.perlmonks.org/?node_id=334610

Thanks to Philip Stoev for the idea of the patch.

The '@' symbol can not be used in the host name according to rfc952.
The fix:
added function check_host_name(LEX_STRING *str)
which checks that all symbols in host name string are valid and
host name length is not more than max host name length
(just moved check_string_length() function from the parser into check_host_name()).

The problem:
I_S views table does not check the presence of SHOW_VIEW_ACL|SELECT_ACL
privileges for a view. It leads to discrepancy between SHOW CREATE VIEW
and I_S.VIEWS.
The fix:
added appropriate check.

            
When analyzing the possible index use cases the server was re-using an internal structure.
This is wrong, as this internal structure gets updated during the analysis.
Fixed by making a copy of the internal structure for every place it needs to be used.
Also stopped the generation of empty SEL_TREE structures that unnecessary 
complicate the analysis.

Re-enabling failing test case because server logs were lost in pushbuild, so we need to run it again.

This patch contains fixes for two problems:

1. As originally reported, the server crashed on Mac OS X when trying to access
   an EXAMPLE table after the EXAMPLE plugin was installed.

   It turned out that the dynamically loaded EXAMPLE plugin called the
   function hash_earch() from a Mac OS X system library, instead of
   hash_earch() from MySQL's mysys library. Makefile.am in storage/example
   does not include libmysys. So the Mac OS X linker arranged the hash_search()
   function to be linked to the system library when the shared object is
   loaded.

   One possible solution would be to include libmysys into the linkage of
   dynamic plugins. But then we must have a libmysys.so, which must be
   used by the server too. This could have a minimal performance impact,
   but foremost the change seems to bee too risky at the current state of
   MySQL 5.1.

   The selected solution is to rename MySQL's hash_search() to my_hash_search()
   like it has been done before with hash_insert() and hash_reset().

   Since this is the third time, we need to rename a hash_*() function,
   I did renamed all hash_*() functions to my_hash_*().

   To avoid changing a zillion calls to these functions, and announcing
   this to hundreds of developers, I added defines that map the old names
   to the new names.

   This change is in hash.h and hash.c.

2. The other problem was improper implementation of the handlerton-to-plugin
   mapping. We use a fixed-size array to hold a plugin reference for each
   handlerton. On every install of a handler plugin, we allocated a new slot
   of the array. On uninstall we did not free it. After some uninstall/install
   cycles the array overflowed. We did not check for overflow.

   One fix is to check for overflow to stop the crashes.

   Another fix is to free the array slot at uninstall and search for a free slot
   at plugin install.

   This change is in handler.cc.

Repush of change to fix tests on Pushbuild.

Link with mtmalloc on Solaris as it is done in our release builds.
Replace deprecated flag with the newer option as already done in
other scripts.

Post-merge bug fix: lock_type is a enumeration type and not a bit mask.

Server created "arc" directories inside database directories and
maintained there useless copies of .frm files.

Creation and renaming procedures of those copies as well as
creation of "arc" directories has been discontinued.
Removal procedure has been kept untouched to be able to
cleanup existent database directories by the DROP DATABASE
query. Also view renaming procedure has been updated to remove
these directories.

     JOIN for the subselect wasn't cleaned if we came upon an error
     during sub_select() execution. That leads to the assertion failure
     in close_thread_tables()

     part of the 6.0 code backported

per-file comments:
  mysql-test/r/sp-error.result
Bug#37949 Crash if argument to SP is a subquery that returns more than one row 
    test result

  mysql-test/t/sp-error.test
Bug#37949 Crash if argument to SP is a subquery that returns more than one row 
    test case

  sql/sp_head.cc
Bug#37949 Crash if argument to SP is a subquery that returns more than one row 
    lex->unit.cleanup() call added if not substatement

The problem is that when statement-based replication was enabled,
statements such as INSERT INTO .. SELECT FROM .. and CREATE TABLE
.. SELECT FROM need to grab a read lock on the source table that
does not permit concurrent inserts, which would in turn be denied
if the source table is a log table because log tables can't be
locked exclusively.

The solution is to not take such a lock when the source table is
a log table as it is unsafe to replicate log tables under statement
based replication. Furthermore, the read lock that does not permits
concurrent inserts is now only taken if statement-based replication
is enabled and if the source table is not a log table.