Move names and types of resulting set to a separate structure. Simplify
their storage by introducing separate members for name and type
(previously names and types were stored in one char * array). It will
allow us to add new metadata properties with ease.

Needed for #4407

Any user defined function features assumed type of returned value
(if it is not set explicitly during UDF creation, then it is ANY).
After function's invocation in SQL, type of returned value is checked to
be compatible with mentioned type of returned value specified in
function's definition. It is done by means of
field_mp_plain_type_is_compatible(). This functions accepts
'is_nullable' arguments which indicates whether value can be nullable or
not. For some reason 'is_nullable' is set to 'false' in our particular
case. Hence, nils can't be returned from UDF for SCALAR types.

Since there's no reason why nils can't be returned from UDFs,
let's fix this unfortunate bug.

It is possible to create a sequence manually, and give it to a newly
created index as a source of unique identifiers. Such sequences are not
owned by a space, and therefore shouldn't be deleted when the space is
dropped. They are not dropped when space:drop() in Lua is called, but
were dropped in SQL 'DROP TABLE' before this patch. Now Lua and SQL are
consistent in that case.

GCC features warning diagnostics which allows to detect wrong ; right
after 'if' operator:

if (X == Y); {
    ...
}

In this case despite evaluation of 'if' argument expression, statements
after it will be always executed.

According to our codestyle, we neglect bracers around 'if' body in case
it consists of single statement and fits into one line. On the other
hand, in SQL debug macros like VdbeComment() are defined as empty, so
statements like:

if (X)
    VdbeComment();

turn into

if (X) ;

in release builds. As a result, we get 'false' warning (which is
compilation error in -Werror mode). To fix it let's make VdbeComment()
macros be non-empty in release mode and expand them into (void) 0.

Dropping table with sql removes everything associated with it but
grants, which is inconsistent. Generating code for it fixes this bug.

Closes #4546

libcurl-7.66.0 and older returns CURLE_WRITE_ERROR when a server
responds with unknown or unsupported Content-Encoding (see [1] and [2]).
This was fixed in future libcurl-7.67.0 and proper
CURLE_BAD_CONTENT_ENCODING code will be returned in this case.

We should process the code in the same way as we do for
CURLE_WRITE_ERROR.

[1]: curl/curl#4310
[2]: curl/curl#4449

Closes #4579

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

CURLOPT_ACCEPT_ENCODING libcurl option is now supported. This option
enables automatic decompression of HTTP responses.

See https://curl.haxx.se/libcurl/c/CURLOPT_ACCEPT_ENCODING.html



Closes #4232

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

@TarantoolBot document
Title: httpc: add curl accept_encoding option

Update the documentation for client_object:request() parameters to
reflect new accept_encoding option.

It enables automatic decompression of HTTP responses by setting the
contents of the Accept-Encoding header sent in a HTTP request and
enabling decoding of a response when a Content-Encoding header is
received.

This is a request, not an order; the server may or may not do it.
Servers might respond with Content-Encoding even without getting an
Accept-Encoding in the request. Servers might respond with a different
Content-Encoding than what was asked for in the request.

@param accept_encoding specifies what encoding you'd like. This param
can be an empty string which means Accept-Encoding header will contain
all built-in supported encodings. This param can be comma-separated list
of accepted encodings, like: "br, gzip, deflate".

Bundled libcurl supports "identity", meaning non-compressed, "deflate"
which requests the server to compress its response using the zlib
algorithm and "gzip" which requests the gzip algorithm. System libcurl
also possibly supports "br" which is brotli.

See https://curl.haxx.se/libcurl/c/CURLOPT_ACCEPT_ENCODING.html

After executing curl request we need to process curl_request code. It
might be CURLE_WRITE_ERROR. We had special case for it, which assumed
diagnostic message being set and contained corresponding assert, though
it is incorrect. Better way is to handle it as any other non-standard
event.

It was discovered while adding accept_encoding option. In case of
unknown encoding curl_request code is currently set to CURLE_WRITE_ERROR
and therefore we come to an assert assuming we have some diagnostics
set. However, it is not being set and it is totally fine. This means we
are failing on assert and it is not correct behavior.

Prerequisites: #4232

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

This patch fixes a bug that appeared after commit
3a13be1d ('lua: fix lua_tofield()
for 2**64 value') .

Due to this bug, -2^63 was serialized as double, although it
should be serialized as integer.

Closes #4672

Isolated tuple update is an update by JSON path, which hasn't a
common prefix with any other JSON update operation in the same
set. For example, these JSON update operations are isolated:

    {'=', '[1][2][3]', 100},
    {'+', '[2].b.c', 200}

Their JSON paths has no a common prefix. But these operations are
not isolated:

    {'=', '[1][2][3]', 100},
    {'+', '[1].b.c', 200}

They have a common prefix '[1]'.

Isolated updates are a first part of fully functional JSON
updates. Their feature is that their implementation is relatively
simple and lightweight - an isolated JSON update does not store
each part of the JSON path as a separate object. Isolated update
stores just string with JSON and pointer to the MessagePack
object to update.

Such isolated updates are called 'bar update'. They are a basic
brick of more complex JSON updates.

Part of #1261

Before this patch if user passed {verbose = false}
to http client it was considered as "true"

This patch fixes such behaviour and takes into account
user's value

Some built-in functions can accept different number of arguments.
Check of argument count for such functions takes place right before
its execution. So it is possible that expression-list representing
arguments for built-in function is NULL. On the other hand, in
sql_expr_coll() (which returns collation of expression) it is assumed
that if function features SQL_FUNC_DERIVEDCOLL flag (it implies that
resulting collation depends on collation of arguments) then it has at
least one argument. The last assumption is wrong considering for example
SUBSTR() function: it may have 1 or 2 arguments, so check of argument
count doesn't occur during compilation. Hence, if it is required to
calculate collation for SUBSTR() function and there's no arguments,
Tarantool crashes due to null-dereference.
This patch fixes this bug with one additional check in sql_expr_coll().

JetBrains IDEs use .idea folder to store configuration files.
To provide more comfort for it's users .idea folder should be ignored.

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

As long as we are sure, that strlen(sd_unix_path) < sizeof(sa.sun_path)
we can assume that there is always enough space and the path will be
null-terminated. Thus, copy 1 byte less to get rid of the warning.

Closes #4515

The test started failing after my commit:
ca07088c
(func: fix not unloading of unused modules), because I forgot to
update the result file.

Follow up #4648

This patch fixes a bug that prevented the conversion of real
values that are greater than INT64_MAX and less than UINT64_MAX to
INTEGER and UNSIGNED.

Closes #4526

The sqlVdbeMemIntegerify() function accepts the is_forced flag as
one of the arguments. But this flag is actually useless, because
regardless of whether it is TRUE or FALSE, the function will do
the same. This patch removes the is_forced argument from the
function. There will be no test, since the result of the function
has not changed.

Part of #4526

According to code coio_call does not take a timeout as an argument,
however it was mentioned in the comment and usage example. This lead to
error in documentation. The patch fixes it.

Closes #4663

C functions are loaded from .so/.dylib dynamic libraries. A
library is loaded when any function from there is called first
time. And was supposed to be unloaded, when all its functions are
dropped from the schema (box.schema.func.drop()), and none of them
is still in a call. But the unloading part was broken.

In fact, box.schema.func.drop() never unloaded anything. Moreover,
when functions from the module were added again without a restart,
it led to a second mmap of the same module. And so on, the same
library could be loaded any number of times.

The problem was in a useless flag in struct module preventing its
unloading even when it is totally unused. It is dropped.

Closes #4648

Error injections are used to simulate an error. They are
represented as a flag, or a number, and are used in Lua tests. But
they don't have any feedback. That makes impossible to use the
injections to check that something has happened. Something very
needed to be checked, and impossible to check in a different way.

More certainly, the patch is motivated by a necessity to count
loaded dynamic libraries to ensure, that they are loaded and
unloaded when expected. This is impossible to do in a platform
independent way. But an error injection as a debug-only counter
would solve the problem.

Needed for #4648

There is a bug in XCode 11 which makes some standard C headers
not self sufficient when compile with gcc. At least <stdlib.h> and
<algorithm> are affected. When they are included first,
compilation fails with creepy errors like this:

    In file included
    from /Applications/Xcode.app/Contents/Developer/
        Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/
        sys/wait.h:110,
    from /Applications/Xcode.app/Contents/Developer/
        Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/
        stdlib.h:66,
    from tarantool/third_party/zstd/lib/common/zstd_common.c:16:
        /Applications/Xcode.app/Content/Developer/
        Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/
        sys/resource.h:
    In function 'getiopolicy_np': /Applications/Xcode.app/Contents/Developer/
        Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/
        sys/resource.h:447:34: error:
            expected declaration specifiers before '__OSX_AVAILABLE_STARTING'
            447 | int     getiopolicy_np(int, int)
            __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);

The patch workarounds the bug by deleting the buggy header
includes where possible, and by changing include order in other
cases.

Also there was a second compilation problem. This was about
different definitions of the same standard functions: via extern
"C" and without. It looked like this:

    In file included from tarantool/src/trivia/util.h:36,
    from tarantool/src/tt_pthread.h:35,
    from tarantool/src/lib/core/fiber.h:38,
    from tarantool/src/lib/core/coio.h:33,
    from tarantool/src/lib/core/coio.cc:31:
    /usr/local/Cellar/gcc/9.2.0_1/lib/gcc/9/gcc/x86_64-apple-darwin18/9.2.0
    include-fixed/stdio.h:222:7: error: conflicting declaration of
    'char* ctermid(char*)' with 'C' linkage
      222 | char *ctermid(char *);
          |       ^~~~~~~

    In file included from /Applications/Xcode.app/Contents/Developer/Platforms/
    MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
    from tarantool/src/lib/core/fiber.h:37,
    from tarantool/src/lib/core/coio.h:33,
    from tarantool/src/lib/core/coio.cc:31:
    /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/
    Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous
    declaration with 'C++' linkage
      26 | char    *ctermid(char *);
         |          ^~~~~~~

This bug is workarounded by deletion of the conflicting includes,
because anyway they appeared to be not needed.

Closes #4580

Conflicts:
	third_party/decNumber

New commit fixes build on XCode 11.

snrpintf always null-terminates the passed string, and it also returns
the number of bytes that "would have been written if there was enough
space", so not only we don't have to null-terminate the string, but even
more so we shouldn't do it erroneously. The only case when a string
should be null-terminated manually is when the print cycle doesn't run
at all, so move the termination before the cycle.

Closes #4636

The tarantool_free() call in the end of main() works all the time except
when we exit due to a panic. We need to clear terminal state in this
case also, so return to using atexit() to clear readline state.

Closes #4466

Unicode_ci collation breaks the general
rule for objects naming, so we remove it
in version 2.3.1

Closes #4561

After the commit 77fa45bd
('lua: add fiber.top() listing fiber cpu consumption')
the unit tests builds failed like:

/opt/rh/devtoolset-6/root/usr/libexec/gcc/x86_64-redhat-linux/6.3.1/ld:
  ../../src/lib/core/libcore.a(fiber.c.o): undefined reference to symbol
  'clock_gettime@@GLIBC_2.2.5'
//lib64/librt.so.1: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
test/unit/CMakeFiles/cbus.test.dir/build.make:108: recipe for target
  'test/unit/cbus.test' failed
make[2]: *** [test/unit/cbus.test] Error 1

Found that fiber.cc is using now clock_gettime(), which requires -lrt
with glibc. To fix it added librt dependency for core library for glibc.
Due to glibc requires for -lrt for clock_gettime() only for some
versions, check 'man clock_gettime.2':
  'Link with -lrt (only for glibc versions before 2.17).'
the check whether is able to use clock_gettime() w/o librt library is
added.

Close #4639

(cherry picked from commit 99b0ef771135eab66ef3758371b1b5431e21cbff)

It was requested to be raised from 32 to 128

Closes #4670

The problem was in that the test uses the global trigger
box.session.on_disconnect() to set a global variable by one
connection. But test-run can do multiple connects/reconnects to
the same instance. That led to multiple invocations of
box.session.on_disconnect(), which could override the global
variable in unexpected ways and moments.

The patch makes only one session execute that trigger.

Probably related to https://github.com/tarantool/test-run/issues/46


Follow up #4627

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

List of changes
     - fold: keep type of emitted CONV in sync with its mode
     - test: adjust the test name related to PAIRSMM flag

Turns on LUAJIT_ENABLE_PAIRSMM flag for tarantool build.
Now __pairs/__ipairs metamethods are available.

Closes #4650

Added build + test jobs in GitLab-CI and build + test + deploy jobs on
Travis-CI for Fedora 31.

Updated testing dependencies in the RPM spec to follow the new Python 2
package naming scheme that was introduced in Fedora 31: it uses
python2-' prefix rather then 'python-'.

Fedora 31 does not provide python2-gevent and python2-greenlet packages,
so they were pushed to https://packagecloud.io/packpack/backports
repository. This repository is enabled in our build image
(packpack/packpack:fedora-31) by default. Those dependencies are build-time,
so nothing was changed for a user. The source RPM packages were gathered
from https://rpms.remirepo.net/rpmphp/

.

Closes #4612

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>

Strengthen test_run:cmd() against temporary connection failures (#193).

We recently added 'replication/box_set_replication_stress' test that may
exceed file descriptor limit. When test_run:cmd() function executes a
command ('switch master' in the case), it tries to create a new socket
and connect it to test-run's inspector, but it may fail to do so in the
case, because of the file descriptor limit.

The sockets that the test produces are closed in background, so if we'll
keep trying to create and connect a socket we'll succeed once. This is
exactly that the test-run's patch doing: it fails test_run:cmd()
function only if a socket cannot be connected during 100 seconds.

I guess that the reason why sockets are not closed immediately is that
relays wait until replicas will close its side of a socket and only then
closes its side. Didn't investigate it deeper, to be honest.

Inside json_decode() struct luaL_serializer is allocated on stack, but
json context stores pointer to it:

   998	static int json_decode(lua_State *l)
   999	{
  ...
  1007	    if (lua_gettop(l) == 2) {
  1008	        struct luaL_serializer user_cfg = *luaL_checkserializer(l);
  1009	        luaL_serializer_parse_options(l, &user_cfg);
  1010	        lua_pop(l, 1);
  1011	        json.cfg = &user_cfg;
  1012      }

Later (for instance in json_decode_descend()), it can be dereferenced
which in turn results in stack-use-after-scope (object turns into
garbage right after scope is ended). To fix it let's simply avoid
allocating and copying luaL_serializer on stack and instead use pointer
to it.

Bug is found by ASAN: test app-tap/json.test.lua fails with enabled
ASAN. Current fix allows to pass all tests.

Thanks to @Korablev77 for the initial investigation.

Closes #4637

This reverts commit a0b196dd.

This commit was pushed occasionally and points to a draft commit in
test-run repository. See also
https://github.com/tarantool/test-run/issues/195

There were some pass conditions in quorum test which could take some
time to be satisfied. Now they are wrapped using test_run:wait_cond to
make the test stable.

Closes #4586

In replicaset_follow we iterate anon replicas list: list of replicas
that haven't received an UUID. In case of successful connect replica
link is being removed from anon list. If it happens immediately,
without yield in applier, iteration breaks. Now it is fixed by
rlist_foreach_entry_safe instead of common rlist_foreach_entry.
Relevant test case is added.

Part of #4586
Closes #4576
Closes #4440

During pruning of appliers some anon replicas might connect
from replicaset_follow called in another fiber. Therefore we need to
prune appliers of anon replicas first and, moreover, prune them one by
one instead of iterating them, as far as any of them might connect
while we are stopping the other one and it will break iteration.

Part of #4586
Closes #4643

Stabilize tcp_connect in test_run:cmd() (tarantool/test-run#193)

Triggers don't throw exceptions any more. Now they have
return codes to report errors.

Closes #4247

Since refactoring: clear privilege managing triggers from exceptions
(977fca29) we are doing zero memset for
trigger struct in txn_alter_trigger_new. This means we don't any more
need to set any field of this struct to NULL explicitly. 

Part of #4247