If openat is present on the system and it tries to open a symlink with
O_NOFOLLOW, we get errno 40.

If openat is not present on the system, we use the alternative open call, with
slightly different logic. IF the symlink doesn't point to a valid file,
we get errno 20. This test uses an invalid symlink on the table t1.MYD.

fil_parse_write_crypt_data(): Correct the comparison operator.
This was broken in commit 498f4a82
which removed a signed/unsigned mismatch in these comparisons.

Also, implement MDEV-11027 a little differently from 5.5 and 10.0:

recv_apply_hashed_log_recs(): Change the return type back to void
(DB_SUCCESS was always returned).

Report progress also via systemd using sd_notifyf().

mysql_client uses some inline assembly code to switch thread stacks.
This works, however tools that perform backtrace get confused to fix
this we write a specific constant to signify bottom of stack. This
constant is needed when compiling with CLang as well.

Also, implement MDEV-11027 a little differently from 5.5:

recv_sys_t::report(ib_time_t): Determine whether progress should
be reported.

recv_apply_hashed_log_recs(): Rename the parameter to last_batch.

This is essentially a backport of the 10.0
commit 203f4d41
that fixes a bug and silences a GCC 6.3.0 warning
about a left shift of a signed integer.

Missing parenthesis in a macro definition caused wrong operation
in the Query_cache::send_result_to_client() statement
   thd->query_plan_flags= (thd->query_plan_flags & ~QPLAN_QC_NO) | QPLAN_QC;

This would expand to
   thd->query_plan_flags= (thd->query_plan_flags & ~1) << 6 | 1 << 5;

which would shift the flags by 6 and clear an unrelated flag, instead
of clearing the flag (1 << 6).

Provide more useful progress reporting of crash recovery.

recv_sys_t::progress_time: The time of the last report.

recv_scan_print_counter: Remove.

log_group_read_log_seg(): After after each I/O request,
report progress if needed.

recv_apply_hashed_log_recs(): At the start of each batch,
if there are pages to be recovered, issue a message.

The C++ standard does not allow references to be NULL.
Assign the return value of THD::alloc() to a pointer,
not to a reference.

Bind to an address even if it is not yet configured.

Revoked executable bit from files that are not supposed to be executed directly.
Removed interpreted from files that are not supposed to be executed directly.
Added interpreter to files that are supposed to be executed directly.

        Test results updated.

Use variables in systemd unit file templetes to properly set paths in
final systemd unit files.

Problem: integer literals may be converted to floats for
comparison with decimal data. If the integers are large,
we may lose precision, and give wrong results.

Fix: for
  <non-const decimal expression> <cmp> <const string expression>
  or
  <const string expression> <cmp> <non-const decimal expression>
we override the compare_type chosen by item_cmp_type(), and
do comparison as decimal rather than float.

(cherry picked from commit https://github.com/mysql/mysql-server/commit/1cf3489ba42df1f29c1f3e269443254087505166 and edited by Johannes Weißl <jargon@molb.org>)

        Server audit plugin version updated.

This reverts commit fa59ac50.

This is a non-functional change.

On a related note, the calls fil_system_enter() and fil_system_exit()
are often used in an unsafe manner. The fix of MDEV-11738 should
introduce fil_space_acquire() and remove potential race conditions.

dir_per_db_rename_to_nenexisting_schema: mysqltest fails with no output
percona_kill_idle_trx_tokudb: MariaDB doesn't support kill_idle_trx var
for all SE.

Probably the result is due to a bug fixed on their server. Restoring old
behaviour for now.

TokuDB testsuite makes use of includes not found in our default 10.0.
Cherry pick them from Percona Server's include directory.