Always set SERVER_MORE_RESULTS_EXIST when executing stored procedure statements

If statements produce a result, EOF packet needs this flag (SP ends
with an OK packet). IF statetement does not produce a result, affected rows
count are part of the final OK packet.

select from I_S

Problem:
========
When applier thread tries to access 'variable_name' of
INFORMATION_SCHEMA.SESSION_VARIABLES table through triggers, it results in an
abnormal exit of slave server.

Analysis:
========
At the time of replication of stored routines and triggers, their associated
security context will be sent by the master. The applier thread on the slave
server will use this information to set the required security context for the
execution of stored routines and triggers. This is achieved as follows.

->The stored routine object has a member named 'm_security_ctx' which holds the
  security context received from master.
->The applier thread's security_ctx is stored into a 'backup' object.

->Set the applier thread's security_ctx to 'm_security_ctx'.

->Upon the completion of stored routine execution restore the original security
  context of applier thread from the backup.

During the above process the 'm_security_ctx' object is not initialized
properly. Hence the 'external_user' of 'm_security_ctx' has invalid value for
this variable and accessing this variable results in abnormal exit of server.

Fix:
===
Invoke the Security_context::init() call from the constructor of stored routine
so that 'm_security_ctx' gets initialized properly.

By applying 7bd258c4.

unfortunately, the year 2038 problem prevented me from pushing
the deadline even further into the future.

Fixed issue in logic.

If an IN-subquery is used in a table-less select the current code
should never consider it as candidate for semi-join optimizations.
Yet the function check_and_do_in_subquery_rewrites() improperly
checked the property "to be a table-less select". As a result
such select in IN subquery was used in INSERT .. SELECT then
the IN subquery by mistake was registered as a semi-join subquery
and convert_subq_to_sj() was called for it. However the code of
this function does not assume that the parent select of the subquery
could be a table-less select.

row_mysql_handle_errors(): Correct the wrong error handling for
the code DB_FOREIGN_EXCEED_MAX_CASCADE that was introduced in

https://github.com/mysql/mysql-server/commit/c0923d396aef46799883390e9dcf7bbf173e4a03

    commit 35f5429e
    Author: Jimmy Yang <jimmy.yang@oracle.com>
    Date:   Wed Oct 6 06:55:34 2010 -0700

        Manual port Bug #Bug #54582 "stack overflow when opening many tables
        linked with foreign keys at once" from mysql-5.1-security to
        mysql-5.5-security again.

        rb://391 approved by Heikki

No known test case exists for repeating the bug before MariaDB 10.2.
The scenario should be that DB_FOREIGN_EXCEED_MAX_CASCADE is returned,
then InnoDB wrongly skips the rollback to the start of the current
row operation, and finally the SQL layer commits the transaction.
Normally the SQL layer would roll back either the entire transaction or
to the start of the statement. In the faulty scenario, InnoDB would
leave the transaction in an inconsistent state, and the SQL layer could
commit the transaction.

1. Always drop merged_for_insert flag on cleanup (there could be errors which prevent TABLE to be assigned)
2. Make more precise cleanup of select parts which was touched

st_select_lex::handle_derived() and mysql_handle_list_of_derived() had
exactly the same implementations.

- Adding a new method LEX::handle_list_of_derived() instead
- Removing public function mysql_handle_list_of_derived()
- Reusing LEX::handle_list_of_derived() in st_select_lex::handle_derived()

candle.exe's preprocessor flags (-dHaveUpgradeWizard=0 -DHaveInnodb=1)
were not passed correctly to EXECUTE_PROCESS

Fix is to make a list out of the EXTRA_WIX_PREPROCESSOR_FLAGS string,
and use the preprocessor flags list in EXECUTE_PROCESS.

For multi-table views with LOAD, updates are not allowed, so
we should just throw an error.

For singe-table views, we need to find the bottom most base table in the embedded views
and then update that table

@@open_files_limit now behaves differenly and cannot
be used to skip the test anymore.

Disable LOAD DATA LOCAL INFILE suport by default and
auto-enable it for the duration of one query, if the query
string starts with the word "load". In all other cases the application
should enable LOAD DATA LOCAL INFILE support explicitly.

If the rlimit.rlim_cur value returned by getrlimit is not the
RLIM_INFINITY magic constant, but a *very* large number, we can allocate
too many open files. Restrict set_max_open_files to only return at most
max_file_limit, as passed via its parameter.

Close connection handler on connection failure. This fixes 14 failing tests in
main suite under clang+ASAN build.

ASAN report for main.connect looks like this:
=================================================================
==25495==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 146280 byte(s) in 115 object(s) allocated from:
    #0 0x4fba47 in calloc /fun/cpp_projects/llvm_toolchain/llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:138
    #1 0x5a7a02 in mysql_init /work/mariadb/libmariadb/libmariadb/mariadb_lib.c:977:26
    #2 0x570a7a in do_connect(st_command*) /work/mariadb/client/mysqltest.cc:6096:26
    #3 0x584c39 in main /work/mariadb/client/mysqltest.cc:9321:9
    #4 0x7fd15514db96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310

Indirect leak of 7065600 byte(s) in 115 object(s) allocated from:
    #0 0x4fb80f in __interceptor_malloc /fun/cpp_projects/llvm_toolchain/llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:129
    #1 0x637a83 in my_context_init /work/mariadb/libmariadb/libmariadb/ma_context.c:367:23
    #2 0x59fd16 in mysql_optionsv /work/mariadb/libmariadb/libmariadb/mariadb_lib.c:2738:9
    #3 0x5bc1d4 in mysql_options /work/mariadb/libmariadb/libmariadb/mariadb_lib.c:3242:10
    #4 0x570b94 in do_connect(st_command*) /work/mariadb/client/mysqltest.cc:6103:7
    #5 0x584c39 in main /work/mariadb/client/mysqltest.cc:9321:9
    #6 0x7fd15514db96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310

Indirect leak of 940240 byte(s) in 115 object(s) allocated from:
    #0 0x4fb80f in __interceptor_malloc /fun/cpp_projects/llvm_toolchain/llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:129
    #1 0x64386e in ma_init_dynamic_array /work/mariadb/libmariadb/libmariadb/ma_array.c:49:31
    #2 0x649ead in _hash_init /work/mariadb/libmariadb/libmariadb/ma_hash.c:52:7
    #3 0x5a3080 in mysql_optionsv /work/mariadb/libmariadb/libmariadb/mariadb_lib.c:2938:13
    #4 0x5bc20c in mysql_options4 /work/mariadb/libmariadb/libmariadb/mariadb_lib.c:3248:10
    #5 0x56f63b in connect_n_handle_errors(st_command*, st_mysql*, char const*, char const*, char const*, char const*, int, char const*) /work/mariadb/client/mysqltest.cc:5874:3
    #6 0x57146b in do_connect(st_command*) /work/mariadb/client/mysqltest.cc:6193:7
    #7 0x584c39 in main /work/mariadb/client/mysqltest.cc:9321:9
    #8 0x7fd15514db96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
...

Closes #809

don't run `su - mysql` is $USER is already mysql

test case

Issue:
------
When a subquery contains UNION the count of the number of
subquery columns is calculated incorrectly. Only the first
query block in the subquery's UNION is considered and an
array indexing goes out-of-bounds, and this is caught by an
assert.

Solution:
---------
Sum up the columns from all query blocks of the query
expression.

Change specific to 5.6/5.5:
---------------------------
The "child" points to the last query block of the UNION
(as opposed to 5.7+ where it points to the first member of
UNION). So "child->master_unit()->first_select()" is used
to reach the first query block of UNION.

PROBLEM
-------
Memory sanitizer reports uninitialized comparisons
in log_in_use(), because strings are compared with
memcmp() instead of strncmp.

FIX
---
Use strncmp() to compare strings

fil_extend_space_to_desired_size(): Invoke fsync() after posix_fallocate()
in order to durably extend the file in a crash-safe file system.

Avoid introducing new dependencies or new syntax.
That is, don't use $(...) and don't assume dirname is present.

And remove unsighty /foo/bar/../xyz from the path. Use dirname
instead of ../

Closes #1086

don't shortcut trying to test for openssl version,
test what is actually needed for a code to compile

Patch by Eugene Kosov.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>

Fix the off-by-one overflow which was introduced with commit
b0fd06a6 (MDEV-15670 - unit.my_atomic failed in buildbot with
Signal 11 thrown)

Closes #1098.

The problem was in calculating of the mask to clear unused null bits in case of using full byte.

mysql_install_db.exe should not remove datadir, if it was not created by
it.

Workaround glibc bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20116
by making unittest threads joinable. It makes code better anyway.

This reverts part of c5427172

Forbid ALTER DATABASE under read_only.