NET::skip_big_packet isn't defined for the embedded server,
hide it in such a case.

            
Some of the server implementations don't support dates later
than 2038 due to the internal time type being 32 bit.
Added checks so that the server will refuse dates that cannot
be handled by either throwing an error when setting date at 
runtime or by refusing to start or shutting down the server if 
the system date cannot be stored in my_time_t.

Patch for bug#52913: Inserted check if mysqlhotcopy script is existing as requested by review. DIsabled the test until bug#54129 will befixed.

Post-push fix.

Post-push fix.

  
Post-push fix.
  
There was a valgrind issue on the loop that checks whether there
are NULL fields in the UNIQUE KEY or not. In detail, for the last 
iteration the server may read out of the key_part array boundaries,
making valgrind to output warnings.

We fix this by correcting the loop, ie, moving the part that reads
from the key_part to be inside the loop statement block. This way
the assignment is protected by the loop condition.

When using Unique Keys with nullable parts in RBR, the slave can
choose the wrong row to update. This happens because a table with
an unique key containing nullable parts cannot strictly guarantee 
uniqueness. As stated in the manual, for all engines, a UNIQUE 
index allows multiple NULL values for columns that can contain 
NULL.

We fix this at the slave by extending the checks before assuming
that the row found through an unique index is is the correct
one. This means that when a record (R) is fetched from the storage
engine and a key that is not primary (K) is used, the server does 
the following: 

 - If K is unique and has no nullable parts, it returns R;
 - Otherwise, if any field in the before image that is part of K
   is null do an index scan;
 - If there is no NULL field in the BI part of K, then return R.

A side change: renamed the existing test case file and added a
test case covering the changes in this patch.

MTR will ignore fully qualified test name entries in disabled.def 
lists. Therefore, it would still run the test case, even if it is
listed.

This patch fix this by extending the check when marking the test
case as disabled to take into consideration not only the cases that
contain the simple test name but also those that contain fully 
qualified test names.

conflicts:
   conflict      configure.in

result file differs on embedded

Field_time::get_date method does not initialize MYSQL_TIME::time_type field.
The fix is to init this field.

            and .tar.gz, windows vs linux..

On Intel x86 machines index selection by the MySQL query
optimizer could sometimes depend on the compiler version and
optimization flags used to build the server binary.

The problem was a result of a known issue with floating point
calculations on x86: since internal FPU precision (80 bit)
differs from precision used by programs (32-bit float or 64-bit
double), the result of calculating a complex expression may
depend on how FPU registers are allocated by the compiler and
whether intermediate values are spilled from FPU to memory. In
this particular case compiler versions and optimization flags
had an effect on cost calculation when choosing the best index
in best_access_path().

A possible solution to this problem which has already been
implemented in mysql-trunk is to limit FPU internal precision
to 64 bits. So the fix is a backport of the relevant code to
5.1 from mysql-trunk.

err_index could be not a member of the share structure or prebuilt
structure passed from MySQL. For now, we resort to the traditional
way of scanning index->table for the index number.

(Added a real error message instead of ER_UNKNOWN_ERROR)