When asking what database is selected, client expected
to *always* get an answer from the server.

We now handle failure more gracefully.

See comments in ticket for a discussion of what happens,
and how things interlock.


client/mysql.cc:
  Handle empty result-sets gracefully, as opposed
  to just result sets with n>0 items that may themselves
  be empty.

fix for 29125).

mysql-client used static buffer to concatenate server-
version and version_comment. Sufficiently long comments
could get cut off. This was harmless, but looked daft.

Now using a dynamic buffer instead.

client/mysql.cc:
  Use dynamic rather than static buffer for server
  information. If we can get both version and comment,
  concat them and use that. Otherwise, try to use just
  version. If that fails too, return empty string so
  overly trusting callers do not crash. Release memory
  as needed.

Antony Dovgal <tony @ daylessday.org> .  SCA signed and faxed to
tel:+1-408-715-2540.  Patches tweaked by Chad.

continue to update it at make-time.

One shouldn't need to run "make" on server source to get the stuff we say
plugins should use.

functions
      
Unknown timezone specifications are properly rejected
by the server, but are copied into tz_storage before
rejection, and hence is retained until end of server 
life. With sufficiently large bogus timezone specs, 
it is easy to exhaust system memory.
      
Allocation of memory for a copy of the timezone
name is delayed until after verification of validity,
at the cost of a memcpy of the timezone info. This 
only happens once, future lookups will hit the cached
structure.

for bug #41486. Session max_allowed_packet is read-only
as of MySQL 5.1.31. In addition, the global variable
now has no effect on the current session.

fixed help message


client/mysql.cc:
  fixed help message

Don't throw an error after checking the first and the second arguments.
Continue with checking the third and higher arguments and if some of
them is stronger according to coercibility rules,
then this argument's collation is set as result collation.


mysql-test/r/ctype_collate.result:
  test result
mysql-test/t/ctype_collate.test:
  test case
sql/item.cc:
  Don't throw an error after checking the first and the second arguments.
  Continue with checking the third and higher arguments and if some of
  them is stronger according to coercibility rules,
  then this argument's collation is set as result collation.