The code to get read the value of a system variable was extracting its value 
on PREPARE stage and was substituting the value (as a constant) into the parse tree.
Note that this must be a reversible transformation, i.e. it must be reversed before
each re-execution.
Unfortunately this cannot be reliably done using the current code, because there are
other non-reversible source tree transformations that can interfere with this
reversible transformation.
Fixed by not resolving the value at PREPARE, but at EXECUTE (as the rest of the 
functions operate). Added a cache of the value (so that it's constant throughout
the execution of the query). Note that the cache also caches NULL values.
Updated an obsolete related test suite (variables-big) and the code to test the 
result type of system variables (as per bug 74).

so that if the substitution contains single-quotes, the program will fail.

      
    problems are located in the sql_partition.cc where functions calculation
    partition_id don't expect error returned from item->val_int().
    Fixed by adding checks to these functions.
    Note  - it tries to fix more problems than just the reported bug.
      
per-file comments:
modified:
  mysql-test/r/partition.result
    Bug#38083 Error-causing row inserted into partitioned table despite error
        test result
  mysql-test/t/partition.test
    Bug#38083 Error-causing row inserted into partitioned table despite error
        test case
  sql/opt_range.cc
    Bug#38083 Error-causing row inserted into partitioned table despite error
        get_part_id() call fixed
  sql/partition_info.h
    Bug#38083 Error-causing row inserted into partitioned table despite error
        get_subpart_id_func interface changed. 
  sql/sql_partition.cc
    Bug#38083 Error-causing row inserted into partitioned table despite error
        various functions calculationg partition_id and subpart_id didn't expect
            an error returned from item->val_int().  Error checks added.

with actual tree

(no conflicts)

The problem was that the test was trying to obtain a lock on
a table in one connection without ensuring that a insert which
was executed in another connection had released the lock on the
same table.

The solution is to add a dummy select query after the insert to
ensure that the table is unlocked and closed by the time it tries
to lock it again. This is enough to prevent test failures described
in the bug report. As an extra safety measure, concurrent inserts
are disabled.

Remove comments that calculated the Table_locks_immediate. This
value is not tested anymore and it's calculation did not reflect
the actual value.

Function uses a variable only available under debug mode.

The test failed originally -- did not reset binlogging - for the reason
identified by bug@15580.
However it never can be run on the embedded platfrom for yet another cause -
the embedded can not KILL query.
      
Comments added to the test particularly relating `reset master'
to the mentioned bug.

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

The grep expression that finds a running "mysqld" program fails if the
"mysqld_safe" is running with the same PID.

Now, excise "ps" output that has the word " grep" or "mysqld_safe" in 
it, to be a little more certain that the matched process is not a false 
positive hit.  This will fail when the path to mysqld contains either
of those two names, which should be acceptable.

Additionally, some text to search could be truncated if very long.  
Expand the number of lines "ps" emits.

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.

"Data too long" in some configurations, tests "<ENGINE>_func_view" fail

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()).

                  tests "<ENGINE>_func_view" fail

Bug#38762 main.federated_bug_25714 fails sporadically

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.

                  is inconsistent
+ several improvements
Details:
- The subtest with assignment of floating point numbers to
  DECIMAL parameters in functions and procedures checks
  now that the final DECIMAL value is the same as if we assign
  the floating point numbers to columns, user variables etc.
  = The impact of math libs or truncation must be the same.
- Remove storage engine variants of this test because the
  stored procedure properties tested do not depend on
  the storage engine.
  Use the fastest storage engine (MEMORY) for any tables
  needed.
- reset global sort_buffer_size to startup value
- Partially improved formatting.

            
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.