Extract substr into local variable

a "if"
Bug #41913 mysqltest cannot source files from if inside while
Some commands require additional processing which only works first time
Keep content for write_file or append_file with the st_command struct
Add tests for those cases to mysqltest.test

Some follow-up test fixes after seeing effect in PB2

Rewrote logic (first commit was incomplete, sorry)

Apparently caused by logging to table
Turn on logging to file only, add to .opt file for tests needing log to table

Moved some dynstr_free() further up

into "trunk-build".

that was already analyzed by Oracle: EXPLAIN can return 3 or 4 in "rows"; using replace_column to work around this.

mysql-test/include/index_merge2.inc:
  replace "rows" column of some EXPLAINs by "#", if told so
mysql-test/r/index_merge_innodb.result:
  result update
mysql-test/t/index_merge_innodb.test:
  tell index_merge2.inc to accept random "rows" values in some EXPLAINs; we don't do this in index_merge_myisam.test
  which has no randomness here.

Applying fix from Oracle (Marko) for Bug #46657 "InnoDB plugin: invalid read in index_merge_innodb test (Valgrind)"

Enabled proper pattern for Warnings and ERRORs
Added some suppressions

The problem was that creating a DECIMAL column from a decimal
value could lead to a failed assertion as decimal values can
have a higher precision than those attached to a table. The
assert could be triggered by creating a table from a decimal
with a large (> 30) scale. Also, there was a problem in
calculating the number of digits in the integral and fractional
parts if both exceeded the maximum number of digits permitted
by the new decimal type.

The solution is to ensure that truncation procedure is executed
when deducing a DECIMAL column from a decimal value of higher
precision. If the integer part is equal to or bigger than the
maximum precision for the DECIMAL type (65), the integer part
is truncated to fit and the fractional becomes zero. Otherwise,
the fractional part is truncated to fit into the space left
after the integer part is copied.

This patch borrows code and ideas from Martin Hansson's patch.

mysql-test/r/type_newdecimal.result:
  Add test case result for Bug#45261. Also, update test case to
  reflect that an additive operation increases the precision of
  the resulting type by 1.
mysql-test/t/type_newdecimal.test:
  Add test case for Bug#45261
sql/field.cc:
  Added DBUG_ASSERT to ensure object's invariant is maintained.
  Implement method to create a field to hold a decimal value
  from an item.
sql/field.h:
  Explain member variable. Add method to create a new decimal field.
sql/item.cc:
  The precision should only be capped when storing the value
  on a table. Also, this makes it impossible to calculate the
  integer part if Item::decimals (the scale) is larger than the
  precision.
sql/item.h:
  Simplify calculation of integer part.
sql/item_cmpfunc.cc:
  Do not limit the precision. It will be capped later.
sql/item_func.cc:
  Use new method for allocating a new decimal field.
  Add a specialized method for retrieving the precision
  of a user variable item.
sql/item_func.h:
  Add method to return the precision of a user variable.
sql/item_sum.cc:
  Use new method for allocating a new decimal field.
sql/my_decimal.h:
  The integer part could be improperly calculated for a decimal
  with 31 digits in the fractional part.
sql/sql_select.cc:
  Use new method which truncates the integer or decimal parts
  as needed.

 - Add conditionals for bundled zlib and innodb plugin.
 - Apply patch from bug#46834 to install the test suite in RPMs.
 - Add plugins to RPMs.  Disable example plugins.

in lock_table_remove_low on INSERT SELECT) to mysql-trunk.

INSERT ... SELECT ...

Problem was that when bulk insert is used on an empty
table/partition, it disables the indexes for better
performance, but in this specific case it also tries
to read from that partition using an index, which is
not possible since it has been disabled.

Solution was to allow index reads on disabled indexes
if there are no records.

Also reverted the patch for bug#38005, since that was a workaround
in the partitioning engine instead of a fix in myisam.

mysql-test/r/partition.result:
  Bug#46639: 1030 (HY000): Got error 124 from storage engine on
  INSERT ... SELECT ...
  
  updated result file
mysql-test/t/partition.test:
  Bug#46639: 1030 (HY000): Got error 124 from storage engine on
  INSERT ... SELECT ...
  
  Added testcase
sql/ha_partition.cc:
  Bug#46639: 1030 (HY000): Got error 124 from storage engine on
  INSERT ... SELECT ...
  
  reverted the patch for bug#38005, since that was a workaround
  around this problem, not needed after fixing it in myisam.
storage/myisam/mi_search.c:
  Bug#46639: 1030 (HY000): Got error 124 from storage engine on
  INSERT ... SELECT ...
  
  Return HA_ERR_END_OF_FILE instead of HA_ERR_WRONG_INDEX
  when there are no rows.

(temporary) TABLE, crash

Problem: if one has an open "HANDLER t1", further "TRUNCATE t1" 
doesn't close the handler and leaves handler table hash in an 
inconsistent state, that may lead to a server crash.

Fix: TRUNCATE should implicitly close all open handlers.

Doc. request: the fact should be described in the manual accordingly.


mysql-test/r/handler_myisam.result:
  Fix for bug #46456 [Ver->Prg]: HANDLER OPEN + TRUNCATE + DROP
  (temporary) TABLE, crash
    - test result.
mysql-test/t/handler_myisam.test:
  Fix for bug #46456 [Ver->Prg]: HANDLER OPEN + TRUNCATE + DROP
  (temporary) TABLE, crash
    - test case.
sql/sql_delete.cc:
  Fix for bug #46456 [Ver->Prg]: HANDLER OPEN + TRUNCATE + DROP
   (temporary) TABLE, crash
    - remove all truncated tables from the HANDLER's hash.