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.

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.

 - 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.

(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.