After this patch, variable names will have to follow the rules defined
for identifiers in SQL. Essentially, this means that a digit can no
longer be used as the first character of a bind variable name.

Part of #4763

NO_DOC=Will be added later.
NO_CHANGELOG=Will be added later.

The `${{ github.ref_name }}` expression is always evaluated to 'master'
because the workflow is running on the 'master' branch. But it is wrong
in the case of the '2.10' branch. Now it's fixed.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

The '2.8' branch is no longer supported. So let's switch to '2.10'.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

The perf_sysbench.yml workflow has the 'workflow_dispatch' trigger
that is often used to test some workflow changes. To not litter in
the InfluxDB prod bucket, MyTeam chat and mailing list, the special
option is added (Debug mode). When checking this option the InfluxDB
test bucket, MyTeam chat, and mailing list will be used.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Since analyzing the performance test results via the workflow artifacts
is quite inconvenient (we need to download the artifact, unpack it, look
through results), we need a more human approach to see the test report.
Moreover, it would be cool to see the performance difference between the
commits.

So this patch adds reporting the performance test results to MyTeam chat
and mailing list. Furthermore, the comparison of test results is added
to the report. Seeing the test report in the chat or mail is very simple
and convenient, plus forever results history as a bonus.

The test report looks something like this:

    # Curr:
    #   branch:  add-feature-y
    #   build:   1.2.3-42-g6c71c3901
    #   summary: Add feature Y
    #   machine: x86_64
    #   distrib: ce
    #   gc64:    false
    # Prev:
    #   branch:  add-feature-x
    #   build:   1.2.3-41-g5271240ea
    #   summary: Add feature X
    #   machine: x86_64
    #   distrib: ce
    #   gc64:    false
    +----------------------+----------+----------+----------+
    |Sysbench              | Curr(rps)| Prev(rps)|     Ratio|
    +----------------------+----------+----------+----------+
    |oltp_delete           | 11408.000| 11532.000|     0.989|
    |oltp_insert           | 31455.000| 31322.000|     1.004|
    |oltp_point_select     | 65031.000| 66486.000|     0.978|
    |oltp_read_only        |  1732.000|  1735.000|     0.998|
    |oltp_read_write       |  1211.000|  1196.000|     1.013|
    |oltp_update_index     | 15580.000| 15570.000|     1.001|
    |oltp_update_non_index | 16129.000| 16093.000|     1.002|
    |oltp_write_only       |  4482.000|  4434.000|     1.011|
    |select_random_points  | 18525.000| 18517.000|     1.000|
    |select_random_ranges  |  4364.000|  4331.000|     1.008|
    +----------------------+----------+----------+----------+
    |gmean                 |  9223.593|  9220.182|     1.000|
    +----------------------+----------+----------+----------+

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Since recently we partially support timezone names (i.e. as
abbreviations) so we may modify tz attribute support for
datetime constructors or :set() operations.

Closes #7076
Relates to #7007

@TarantoolBot document
Title: datetime tz attribute

Now `tz` attribute is properly handled in datetime value
constructors or `:set{}` method modifiers.

```
tarantool> T = date.new{year = 1980, tz = 'MSK'}
---
...

tarantool> T.tzoffset
---
- 180
...

tarantool> T.tz
---
- MSK
...
tarantool> T = date.new{year = 1980, tzoffset = 180}
---
...

tarantool> T.tzindex
---
- 0
...

tarantool> T.tz
---
-
...

tarantool> T.tzoffset
---
- 180
...

tarantool> T:set{tz = 'MSK'}
---
...

tarantool> T.tz
---
- MSK
...

```

It looks like we have some files in the source tree that are not used
anymore. So there is no sense to keep them.
Files to be deleted: .appveyor.yml, Jenkinsfile, snapcraft.yaml.

NO_DOC=files removal
NO_TEST=files removal
NO_CHANGELOG=files removal

It doesn't work, because fio.rmtree doesn't accept wildcards.
Let's delete the whole server working tree on cleanup.

NO_DOC=test
NO_CHANGELOG=test

Similar to RLIST_HEAD_INITIALIZER and RLIST_HEAD. Needed to initialize
a global fiber_cond variable without calling fiber_cond_create.

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

 - Add func_id_by_name to box.internal. It will be used in EE.
 - Don't call box.internal.space.upgrade from box.schema.space.upgrade -
   we will redefine box.schema.space.upgrade in EE instead.

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

This change contains the following improvements:

1. Prettify view in the job list.

   Before:
     - centos_7 / centos_7 (GC64=OFF)
     - centos_7 / centos_7 (GC64=ON)

   After:
     - centos_7 / centos_7
     - centos_7 / centos_7 (gc64)

2. Change possible values for the ${GC64} env variable to
   `true/false` instead of `ON/OFF` which is more traditional.

3. Use `-DLUAJIT_ENABLE_GC64=ON` flag in the `debian/rules` and
   `rpm/tarantool.spec` files directly instead of providing it
   in the workflow files.

Follows-up tarantool/tarantool-qa#159
Follows-up tarantool/tarantool-qa#161

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

 - Cleanup the unreleased directory: leave only fix-string-dequoting.md
   there, which was added after last branching (2.10).
 - Remove 2.10.0-beta1.md, 2.10.0-beta2.md, 2.8.1.md, because they are
   available at the corresponding branches.

NO_DOC=changelogs
NO_TEST=changelogs

Sometimes we would like to run only integration testing and not touch
other tests. Now it can be done by setting the 'integration-ci' label
on a pull request.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

main.cc includes some headers from Tarantool Enterpise (to be more precise -
flightrec.h). To build it we should include proper extra directories.

NO_DOC=<Build fix>
NO_CHANGELOG=<Build fix>
NO_TEST=<Build fix>

ffi.typeof() returns cdata, which in turn can't be concatenated with string
without explicit call of `tostring`. Moreover, passing data of native Lua
type would also generate wrong error. So let's simply raise general error
without mentioning passed type.

NO_DOC=<Internal fix>
NO_CHANGELOG=<Internal fix>

Previously we decided to pass `msg->p_inbuf->rpos` to flight recorder in
order to dump request. However, this is wrong way to do it since `rpos`
is moved only request has been processed, i.e. at the same moment several
requests may have the same `rpos` value. To fix this let's save the start
of unparsed request to `iproto_msg`. There's one detail that should be
clarified to understand that in this case we'll always get valid
pointer to ibuf. Imagine following state of ibuf:
```
+_____________________
|   |  |          |
+---------------------
    ^  ^          ^
  RPOS R2       WPOS
   R1
```
R1 is the first request in the buffer (i.e. rpos points to it);
R2 is the second. One can argue that if R2 is processed faster than R1
than during the dump of R1 its `reqstart` may point to the garbage.
However, dump of request takes place at the bery beginning of request
execution in TX thread. As far as messages are started to be processed
exactly in the same way as they were received, then R1 will be always
dumped before R2 and its further processing.

Follow-up 247515e9

NO_DOC=<No user visible changes>
NO_TEST=<No functional changes>
NO_CHANGELOG=<No functional changes>

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

It looks like the simplest solution to deliver gc64 tarantool builds
is to have a separate repo for it. So this patch removes old stuff
related to the 'tarantool-gc64' package and adds the new logic to
store gc64 packages in a separate repo.

Closes: tarantool/tarantool-qa#161

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Co-authored-by: Yaroslav Lobankov <y.lobankov@tarantool.org>

space_upgrade_check_alter() must be called after the new space
definition is updated.

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

Box read operations (select, min, max, random, pairs) may call a Lua
function via Lua C API if space upgrade (EE feature) is in progress.
This is forbidden if the original function was called via FFI:

https://github.com/tarantool/luajit/commit/4f4fd9ebeb10d53c8e67f45170938f052818e64e

Let's add helper functions to disable FFI for box read operations.
We will use them in EE code.

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

In Lua C code 'struct iterator&' and 'struct iterator*' are handled in
exactly the same way. However, if we create an iterator object in Lua by
calling box_index_iterator via FFI, and pass the object to Lua C, it
will have 'struct iterator*' type, not 'struct iterator&'. In the next
patch we need Lua C functions to work with such objects so let's replace
'struct iterator&' with 'struct iterator*' in C code.

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

clang 13 includes a check for subtraction from NULL pointer which
is considered UB: historically, we had an alignment checking macro
which is affected by this. It seems like the intention of the
macro's author was to implicitly cast the pointer being checked to
uintptr_t without including stddef.h — replace this subtraction
with an explicit cast.

There is no way to set SQL_4_BYTE_ALIGNED_MALLOC, so the corresponding
part of the code was removed. Now there are only 8 byte alignment
assertions.

NO_CHANGELOG=UB fix
NO_DOC=UB fix
NO_TEST=UB fix

Co-authored-by: Georgiy Lebedev <curiousgeorgiy@gmail.com>

Previously,

select "t1"."a" from (select "a" from "t") as "t1";

returned a result column name `t1` instead of `t1.a` because of
incorrect work of a dequoting function. The reason was that
previously sqlDequote() function finished its work when found the
first closing quote.

Old logic worked for simple selects where the column name doesn't
contain an explicit scan name ("a" -> a).
But for the sub-queries results sqlDequote() finished its work right
after the scan name ("t1"."a" -> t1). Now the function continues its
deqouting till it gets the null terminator at the end of the string.

Closes #7063

NO_DOC=don't change any public API, only a bug fix

Co-authored-by: Mergen Imeev <imeevma@gmail.com>

It will be used to stall background space upgrade in tests.

While we are at it, move ERRINJ_TX_DELAY_PRIO_ENDPOINT to restore
the sorted order of the error injection list.

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

We need the new format to apply the upgrade function to a tuple.

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=test
NO_CHANGELOG=test

The helper skips a running test with luatest.skip_if in case executed by
Tarantool Enterprise. It's better than checking the package directly in
the test, because luatest.skip_if prints the reason why the test is
skipped.

NO_DOC=test
NO_CHANGELOG=test

Online space upgrade applies a function to all tuples in a space.
The function should be pinned so we need a new holder type.

Follow-up commit 38b25832 ("box: add space upgrade stubs").

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

Enum keys are usually stored in a const array of const strings.
Fix opt_def::enum_strs type accordingly.

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

So that the caller can figure out the end of fields array without
calling mp_next(). Needed for decoding space upgrade format.

While we are at it, let's also
 - Replace MP_ARRAY assertion with diag_set. This makes the function
   easier to use when the MsgPack format isn't guaranteed to be
   MP_ARRAY.
 - Rearrange arguments so that [out] arguments are grouped together.

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

Fix the following error:

    {"badRequest": {"message": "The requested availability zone is not
    available", "code": 400}}

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

This option very often makes tests fail due to the issue with the max
length of socket paths (107 chars). Let's rely on the VARDIR environment
variable or another default value (/tmp/t) when VARDIR is not defined.

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

This patch changes the length of default socket paths for luatest tests
(when the VARDIR environment variable is not defined). It should reduce
the chance for the issue with the max length of socket paths (107 chars)
to happen.

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

This change adds VARDIR to the PRESERVE_ENVVARS environment variable
to deliver it to 'packpack' docker containers while running packaging
workflows.

NO_DOC=ci
NO_CHANGELOG=ci
NO_TEST=ci

This patch changes the length of socket paths for tests by 2 chars.
It should reduce the chance for the issue with the max length of socket
paths (107 chars) to happen.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Bump test-run to new version with the following changes:

- Change default value for `vardir` option [1]
- Read default value for `vardir` option from env [1]

[1] tarantool/test-run#338

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

Changed return value type in Lua for the following functions from
`uint64_t` to `int64_t`:

* clock.time64
* clock.realtime64
* clock.monotonic64
* clock.process64
* clock.thread64
* fiber.time64
* fiber.clock64

Changed return value type in Module API for the following functions from
`uint64_t` to `int64_t`:

* fiber_time64
* fiber_clock64

Also enhanced clock.test.lua tap test with more testcases

Due to unsigned values returned from time64 family function time
calculations may lead to undesired value overflows. Having two 64-bit
timestamps I cannot just subtract them without prior comparison. It is
used often, for example when calculating time to a deadline (in queues
or for expiration).

Let's measure time, that pass between two sequential clock.time calls:

```lua
print(clock.time() - clock.time()) -- -9.5367431640625e-07
```

It's ok, with double type time return, but what about 64-bit integers?

```
print(clock.time64() - clock.time64()) -- 18446744073709550616
```

It returns weird integer overflow instead of expected `-1000`

This is counterintuitive and gets conflicted with every time functions
from system headers (which are always signed).

If we consider some hypothetical code, that waits some time for a
deadline, then instead of exiting loop, this code will go to "infinite"
(actually 585 years) wait in the case when the deadline was passed.

```lua
do
local ts = clock.time64() + 1e9 -- some_timestamp_in_future, ex: now+1s
-- ...
local remaining = clock.time64() - ts
-- ...
if remaining > 0 then
    fiber.sleep( tonumber(remaining/1e9) )
end
print "1 second passed"
end
```

This is hard to notice (in real tests deadlines are always in the
future), but in a real environment and under high load such cases occur.

1. Since Lua functions will return ffi.typeof `ctype<int64_t>` instead
   of old `ctype<uint64_t>` any code, that uses _strict_ ffi type check
   will fail. But I hardly believe such code ever exists.
2. Low-level Module API also changed, and code, which compiles with
   `-Werror` may also fail. This could be an issue and in such a case we
   may remove the update of module API change. Still, I consider this
   change reasonable, since all C-level API uses signed time values.

@TarantoolBot document
Title: Return type of time64 functions is changed

These C functions in the public API used to return `uint64_t`, now they
return `int64_t`: `clock_realtime64`, `clock_monotonic64`,
`clock_process64`, `clock_thread64`, `fiber_time64()`,
`fiber_clock64()`.

These Lua functions used to return cdata of type `uint64_t`, now they
return cdata of type `int64_t`: `fiber.time64()`, `fiber.clock64()`.

Fix wording, punctuation, and formatting.
Fix dashes, trailing whitespaces, indentation, and file names.

Needed for: #6430

NO_DOC=changelog
NO_TEST=changelog

Co-authored-by: Valeria Khokha <valeria.khokha@gmail.com>
Co-authored-by: Kseniia Antonova <xuniq.is.here@gmail.com>