just as sql_plugin.cc does

because FLUSH STATUS does not reset them, so their values
are affected by previously run tests since the last server restart.

MDEV-11942 BLACKHOLE is no longer active in 10.1 by default, mysql_upgrade not handling the situation

fix the patch. add tests

Try harder to show the table's engine.

If the table's engine is not loaded, the table won't open.
But we can still read the engine name from frm as a string.

Make SELECT <columns> FROM I_S.TABLES behave identically independently
from whether <columns> require opening the table in engine or
<columns> can be filled with only opening the frm.

In particular, fill_schema_table_from_frm() should not silently skip
frms with unknown engine, but should fill the I_S.TABLES row
with NULLs just like fill_schema_table_by_open() does.

this simplifies the code and avoids unnecessary conversions back and forth.
and it works even if the engine is not installed.

this fixes the crash of innodb.innodb-blob --ps-protocol

has_no_default_value() should only fail the insert in the strict mode.

Additionally, don't check for "all fields are given values" twice,
it'll produce duplicate warnings.

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.