idle_write_transaction_timeout

This is a preparatory step for MDEV-13864.
It does not change behavior in any ways. It simply splits methods into smaller peaces.
The intent of this separate patch is to make more readable the main patch for
MDEV-13864 (which will actually move the predicant to args[0]).

1. Splitting fix_length_and_dec() into smaller pieces, adding:
  - bool aggregate_then_and_else_arguments(THD *thd);
  - bool aggregate_switch_and_when_arguments(THD *thd);

2. Splitting find_item() into smaller pieces, adding:
  - Item *find_item_searched();
  - Item *find_item_simple();

3. Splitting print() into smaller pieces, adding:

  - void print_when_then_arguments(String *str, enum_query_type query_type,
                                   Item **items, uint count);
  - void print_else_argument(String *str, enum_query_type query_type, Item *item)

4. Moving the maybe_null handling part related to ELSE from fix_length_and_dec()
   to fix_fields(), as in all other Item_func's.

5. Removing the unused String* argument from find_item().

6. Moving find_item() from public to private, as it's not needed outside.

This could have been done as part of MDEV-11487, which removed the
support for InnoDB internal temporary tables.

Fix description of version_source_revision

Added version_source_revision server "variable", for the git revision.
Also , mysql -V will show git revision.

"make dist" will now pack source_revision.h into the source package.

followup for b5ead3a6

libmariadb3 does not replace 10.1's libmariadbclient18 anymore,
but it still conflicts with it, both install dialog.so

This fixes a regression that only affects debug builds, caused by
commit 48192f96 which is necessary
preparation for MDEV-11369 instant ADD COLUMN. (Although that is a
10.3 task, to ease merges between 10.2 and 10.3, this change that
improves debug checks was pushed to 10.2 already.)

Unlike btr_pcur_restore_position(), rtr_cur_restore_position()
can create a search tuple out of a non-leaf page record. So,
we must pass 'bool leaf' parameter to dict_index_build_data_tuple().

dict_index_build_data_tuple(): Add a debug-only parameter 'bool leaf'.

rec_copy_prefix_to_dtuple(): Make the parameter debug-only.

row_sel_get_clust_rec_for_mysql(): In the debug code for spatial index,
remove an unnecessary call to buf_page_get_gen(), and use the already
latched block directly.

MDEV-13851 Always check table options in ALTER TABLE…ALGORITHM=INPLACE

In the merge of MySQL 5.7.9 to MariaDB 10.2.2, some code was included
that prevents ADD SPATIAL INDEX from being executed with ALGORITHM=INPLACE.

Also, the constant ADD_SPATIAL_INDEX was introduced as an alias
to ADD_INDEX. We will remove that alias now, and properly implement
the same ADD SPATIAL INDEX restrictions as MySQL 5.7 does:

1. table-rebuilding operations are not allowed if SPATIAL INDEX survive it
2. ALTER TABLE…ADD SPATIAL INDEX…LOCK=NONE is not allowed

ha_innobase::prepare_inplace_alter_table(): If the ALTER TABLE
requires actions within InnoDB, enforce the table options (MDEV-13851).
In this way, we will keep denying ADD SPATIAL INDEX for tables
that use encryption (MDEV-11974), even if ALGORITHM=INPLACE is used.

This should affect debug builds only. Debug builds will check that
the status bits of ROW_FORMAT!=REDUNDANT records match the is_leaf
parameter.

The only observable change to non-debug should be the addition of
the is_leaf parameter to the function rec_copy_prefix_to_dtuple(),
and the removal of some calls to update the adaptive hash index
(it is only built for the leaf pages).

This change should have been made in MySQL 5.0.3, instead of
introducing the status flags in the ROW_FORMAT=COMPACT record header.

* remove dead code

* rename method to reduce confusion

The only universal index in InnoDB was the change buffer.
It suffices to keep the DICT_IBUF flag (which, like DICT_UNIVERSAL,
is not written to any persistent data structure).

The function check_mdl_lock_works() is for debug builds only.

Define some page accessor functions inline in page0page.h,
reducing code duplication in page0page.ic.

Use page_rec_is_leaf() instead of page_is_leaf() where possible.

It is only valid for 10.1