Problem: comparison of a DATETIME sp variable and NOW()
led to Illegal mix of collations error when 
character_set_connection=utf8.
Introduced by "WL#2649 Number-to-string conversions".

Error happened in Arg_comparator::set_compare_func(),
because the first argument was errouneously converted to utf8,
while the second argument was not.

Fix: separate agg_arg_charsets_for_comparison() into two functions:

- agg_arg_charsets_for_comparison() - for pure comparison,
  when we don't need to return any string result and therefore
  don't need to convert arguments to @@character_set_connection:
    SELECT a = b;

- agg_arg_charsets_for_string_results_with_comparison() - when
  we need to return a string result, but we also need to do
  comparison internally: SELECT REPLACE(a,b,c)
  If all arguments are numbers:
    SELECT REPLACE(123,2,3) -> 133
  we convert arguments to @@character_set_connection.


  @ mysql-test/include/ctype_numconv.inc
  @ mysql-test/r/ctype_binary.result
  @ mysql-test/r/ctype_cp1251.result
  @ mysql-test/r/ctype_latin1.result
  @ mysql-test/r/ctype_ucs.result
  @ mysql-test/r/ctype_utf8.result
  Adding tests

  @ sql/item.cc
  @ sql/item.h
  @ sql/item_func.cc
  @ sql/item_func.h
  @ sql/item_strfunc.cc

  Introducing and using new function
   agg_item_charsets_for_string_result_with_comparison() and
  its Item_func wrapper agg_arg_charsets_for_string_result_with_comparison().

IF NO DNS-SERVER AVAILABLE.

The thing is that on Windows XP getnameinfo() returns WSANO_DATA
when hostname-lookup is not available. The problem was that
this error code was treated as serious error and the client
connection got rejected.

The fix is to treat all errors from getnameinfo() as not ciritical,
but add IP-address to the host cache only for EAI_NONAME (or WSANO_DATA).

Select from a view with the underlying HAVING clause failed with a
message: "1356: View '...' references invalid table(s) or column(s)
or function(s) or definer/invoker of view lack rights to use them"

The bug is a regression of the fix for bug 11750328 - 40825 (similar
case, but the HAVING cause references an aliased field).
In the old fix for bug 40825 the Item_field::name_length value has
been used in place of the real length of Item_field::name. However,
in some cases Item_field::name_length is not in sync with the
actual name length (TODO: combine name and name_length into a
solid String field).

The Item_ref::print() method has been modified to calculate actual
name length every time.


mysql-test/r/view.result:
  Test case for bug #11829681
mysql-test/t/view.test:
  Test case for bug #11829681
sql/item.cc:
  Bug #11829681 - 60295: ERROR 1356 ON VIEW THAT EXECUTES FINE AS A QUERY
  
  The Item_ref::print() method has been modified to calculate actual
  name length every time.
sql/item.h:
  Minor commentary.

               create_schema if auto-generate-sql also set.

mysqlslap uses a schema to run its tests on and later
drops it if auto-generate-sql is used. This can be a
problem, if the schema is an already existing one.

If create-schema is used with auto-generate-sql option,
mysqlslap while performing the cleanup, drops the specified
database.

Fixed by introducing an option --no-drop, which, if used,
will prevent the dropping of schema at the end of the test.


client/client_priv.h:
  Bug#11765157 - 58090: mysqlslap drops schema specified in
                 create_schema if auto-generate-sql also set.
  
  Added an option.
client/mysqlslap.c:
  Bug#11765157 - 58090: mysqlslap drops schema specified in
                 create_schema if auto-generate-sql also set.
  
  Introduced an option 'no-drop' to forbid the removal of schema
  even if 'create' or 'auto-generate-sql' options are used.
mysql-test/r/mysqlslap.result:
  Added a testcase for Bug#11765157.
mysql-test/t/mysqlslap.test:
  Added a testcase for Bug#11765157.

               PRIMARY KEY NO 0 FOR TABLE IN ERROR LOG 

Post merge fix, update the .result file.