The _vfunc system space is the sysview for the _func system space.
However, the _vfunc format is different from the _func format. This
patch makes the _vfunc format the same as the _func format.

Closes #7822

NO_DOC=bugfix

(cherry picked from commit 707da125)

We used to ignore timezone difference (in `tzoffset`) for
datetime subtraction operation:

```
tarantool> datetime.new{tz='MSK'} - datetime.new{tz='UTC'}
---
- +0 seconds
...

tarantool> datetime.new{tz='MSK'}.timestamp -
           datetime.new{tz='UTC'}.timestamp
---
- -10800
...
```

Now we accumulate tzoffset difference in the minute component
of a resultant interval:

```
tarantool> datetime.new{tz='MSK'} - datetime.new{tz='UTC'}
---
- -180 minutes
...
```

Closes #7698

NO_DOC=bugfix

(cherry picked from commit 0daed8d5)

We did not take into consideration the fact that
as result of date/time arithmetic we could get
in a different timezone, if DST boundary has been
crossed during operation.

```
tarantool> datetime.new{year=2008, month=1, day=1,
			tz='Europe/Moscow'} +
	   datetime.interval.new{month=6}
---
- 2008-07-01T01:00:00 Europe/Moscow
...
```

Now we resolve tzoffset at the end of operation if
tzindex is not 0.

Fixes #7700

NO_DOC=bugfix

(cherry picked from commit 6ca07285)

In PR #7791 the coverage stuff is slightly updated. The changes are
related to excluding some directories where the coverage will not be
calculated. The patch itself is straightforward enough, but I can see
the problems with uploading the results to coveralls.io:

NO_WRAP
    Using lcov file: ./coverage.info
    FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory

    <--- Last few GCs --->

    [2683200:0x327c000]    27836 ms: Scavenge 2033.4 (2038.7) -> 2033.2 (2044.2) MB, 6.8 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure
    [2683200:0x327c000]    27854 ms: Scavenge 2036.7 (2044.2) -> 2037.1 (2044.4) MB, 15.6 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure
    [2683200:0x327c000]    27871 ms: Scavenge 2037.2 (2044.4) -> 2036.7 (2055.9) MB, 17.1 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure

    <--- JS stacktrace --->

    ==== JS stack trace =========================================

        0: ExitFrame [pc: 0x140dc19]
    Security context: 0x2481918808d1 <JSObject>
        1: encode(aka encode) [0x23ec5e514a11] [/opt/actions-runner/_work/_actions/coverallsapp/github-action/v1.1.2/node_modules/qs/lib/utils.js:~118] [pc=0x193ecd3d5d82](this=0x35d34e4804b1 <undefined>,0x1e5895380119 <Very long string[60387428]>)
        2: stringify(aka stringify) [0x23ec5e5174c9] [/opt/actions-runner/_work/_actions/coverallsapp/github-action/v1.1.2/n...

     1: 0xa1a640 node::Abort() [/opt/actions-runner/externals/node12/bin/node]
     2: 0xa1aa4c node::OnFatalError(char const*, char const*) [/opt/actions-runner/externals/node12/bin/node]
     3: 0xb9a62e v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [/opt/actions-runner/externals/node12/bin/node]
     4: 0xb9a9a9 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [/opt/actions-runner/externals/node12/bin/node]
     5: 0xd57c25  [/opt/actions-runner/externals/node12/bin/node]
     6: 0xd582b6 v8::internal::Heap::RecomputeLimits(v8::internal::GarbageCollector) [/opt/actions-runner/externals/node12/bin/node]
     7: 0xd64b75 v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [/opt/actions-runner/externals/node12/bin/node]
     8: 0xd65a25 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [/opt/actions-runner/externals/node12/bin/node]
     9: 0xd670cf v8::internal::Heap::HandleGCRequest() [/opt/actions-runner/externals/node12/bin/node]
    10: 0xd15b35 v8::internal::StackGuard::HandleInterrupts() [/opt/actions-runner/externals/node12/bin/node]
    11: 0x1071176 v8::internal::Runtime_StackGuard(int, unsigned long*, v8::internal::Isolate*) [/opt/actions-runner/externals/node12/bin/node]
    12: 0x140dc19  [/opt/actions-runner/externals/node12/bin/node]
NO_WRAP

I have tried to use the latest version of the action (1.1.3), but I have
got the same issue.

It looks like it is a `coverallsapp/github-action` issue due to issue
in JavaScript due to inefficient amount of memory. The corresponding
bug [1] was filed against the repo.

So I suggest switching to the console utility `coveralls-lcov`. I did
some internal testing and it works fine.

[1] https://github.com/coverallsapp/github-action/issues/133

Fixes tarantool/tarantool-qa#278

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

(cherry picked from commit 761574e3)

This patch fixed the assertion when JOIN uses index of unsupported type.

Closes #5678

NO_DOC=bugfix

(cherry picked from commit fd780129)

Currently if a non-string type is passed to luaT_key_def_set_part,
lua_tolstring returns null-pointer type_name, which is passed to
a string formatting function in diag_set.

Closes #5222

NO_DOC=bugfix

(cherry picked from commit 5215f3f3)

Don't accept an empty string or leading part of "str" or "num" as a
valid field type.

Closes #5940

NO_DOC=Partial field types weren't documented

Co-authored-by: Alexander Turenko <alexander.turenko@tarantool.org>
(cherry picked from commit 2dbaf9c2)

Since the function is actually an eval, by default there should
be no execute access right in public role.

Closes tarantool/security#14

NO_DOC=bugfix

(cherry picked from commit 815788c8)

By design after patching update.lua, introducing new data version,
a developer needs to update bootstrap.snap, which would have the
new data version.

Generation of bootstrap.snap is a bit tricky, there's a manual:
https://github.com/tarantool/tarantool/wiki/How-to-generate-new-bootstrap-snapshot

This commit presents a simple script that automates the process.
Just run it in tarantool build directory and check its output.
Check --help for script options.

Follow-up of tarantool/security#14

NO_DOC=internal tool
NO_TEST=internal tool
NO_CHANGELOG=internal tool

(cherry picked from commit 0922816e)

Fix a simple typo that caused the problem.

Closes #7645

NO_DOC=bugfix

(cherry picked from commit 6e450424)

This patch introduces new rules to determine type of NULLIF() built-in
function.

Closes #6990

@TarantoolBot document
Title: New rules to determine type of result of NULLIF

The type of the result of NULLIF() function now matches the type of the
first argument.

(cherry picked from commit 805cbaa7)

This patch introduces new rules to determine type of CASE operation.

Part of #6990

@TarantoolBot document
Title: New rules to determine type of result of CASE

New rules are applied to determine the type of the CASE operation. If
all values are NULL with no type, or if a bind variable exists among
the possible results, then the type of CASE is ANY. Otherwise, all NULL
values with no type are ignored, and the type of CASE is determined
using the following rules:
1) if all values of the same type, then type of CASE is this type;
2) otherwise, if any of the possible results is of one of the
incomparable types, then the type of CASE is ANY;
3) otherwise, if any of the possible results is of one of the
non-numeric types, then the type of CASE is SCALAR;
4) otherwise, if any of the possible results is of type NUMBER, then the
type of CASE is NUMBER;
5) otherwise, if any of the possible results is of type DECIMAL, then
the type of CASE is DECIMAL;
6) otherwise, if any of the possible results is of type DOUBLE, then the
type of CASE is DOUBLE;
7) otherwise the type of CASE is INTEGER.

(cherry picked from commit 90f64460)

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

(cherry picked from commit e5e14cd6)

If the length of the tuple is greater than the number of fields in the
format, it is possible that the cursor in the VDBE will be overridden
with zeros.

Closes #5310

NO_DOC=bugfix

(cherry picked from commit 89057a21)

Usually, GitHub actions are named like `foo-bar` rather than `foo_bar`.
A few widely known examples: upload-artifact [1], download-artifact [2],
setup-python [3], setup-node [4]. So let's stick to this approach also.

[1] https://github.com/actions/upload-artifact
[2] https://github.com/actions/download-artifact
[3] https://github.com/actions/setup-python
[4] https://github.com/actions/setup-node

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

(cherry picked from commit 3c4a5056)

This patch fixed the assertion when using INDEXED BY with an index that
is at least the third in space.

Closes #5976

NO_DOC=bugfix

(cherry picked from commit 22c65f96)

* FFI: Always fall back to metamethods for cdata length/concat.
* FFI: Add tonumber() specialization for failed conversions.
* build: introduce LUAJIT_ENABLE_CHECKHOOK option
* Fix overflow check in unpack().
* gdb: refactor iteration over frames while dumping stack
* gdb: adjust to support Python 2 (CentOS 7)

Closes #7458
Closes #7655
Needed for #7762
Part of #7230

NO_DOC=LuaJIT submodule bump
NO_TEST=LuaJIT submodule bump

dt.new() will raise a clear error on wrong timestamp type.

Closes #7273

NO_DOC=bugfix
NO_CHANGELOG=bugfix

(cherry picked from commit 8d4cbf44)

Such style is not recommented and going to be banned.

Closes #7715

NO_TEST=test refactoring
NO_DOC=test refactoring
NO_CHANGELOG= test refactoring

(cherry picked from commit ce784430)

Some luatest framework tests use Lua `assert`s, which are incomprehensible
when failed (the only information provided is 'assertion failed!'),
making debugging difficult: replace them with luatest `assert`s and their
context-specific varieties.

NO_CHANGELOG=<code health>
NO_DOC=<code health>

(cherry picked from commit 1d9645f7)

Commit 7f2c7609 ("box: add option to disable Lua FFI for read
operations") added an internal configuration option that switches all
index read operations from FFI to Lua C, which was necessary to
implement space upgrade in the EE repository. Turns out there was a
minor bug in that commit - when FFI is disabled, method usage errors
(raised when object.method is called instead of object:method) stop
working. Fix this bug and add an extensive test that checks that Lua C
and FFI implementations of index read operations are equivalent.

Fixes https://github.com/tarantool/tarantool-ee/issues/254

NO_DOC=bug fix
NO_CHANGELOG=bug manifests itself in only in EE

(cherry picked from commit e8d9a7cb)

Concurrent transactions can try to insert tuples that intersect only by
parts of secondary index: in this case when one of them gets prepared, the
others get conflicted, but the committed story does not get retained
(because the conflicting statements are not added to the committed story's
delete statement list as opposed to primary index) and is lost after
garbage collection: retain stories if there is a newer uncommitted story
in the secondary indexes' history chain.

Closes #7712

NO_DOC=bugfix

(cherry picked from commit 7b0baa57)

Generate changelog for 2.10.3 release.
Also, clean changelogs/unreleased folder.

NO_DOC=no code changes
NO_TEST=no code changes
NO_CHANGELOG=no code changes

NO_CHANGELOG=changelog
NO_DOC=changelog
NO_TEST=changelog

NO_CHANGELOG=changelog
NO_DOC=changelog
NO_TEST=changelog

Fix wording, punctuation, and formatting.

NO_CHANGELOG=changelog
NO_DOC=changelog
NO_TEST=changelog

When using vclockset_psearch, the resulting vclock may be incomparable
to the search key. For example, with a vclock set { } (empty vclock),
{0: 1, 1: 10}, {0: 2, 1:11} vclockset_psearch(set, {0:2, 1: 9}) might
return {0: 1, 1: 10}, and not { }.
This is known and avoided in other places, for example
recover_remaining_wals(), where vclockset_match() is used instead.
vclockset_match() starts with the same result as vclockset_psearch() and
then unwinds the result until the first vclock which is less or equal to
the search key is found.

Having vclockset_psearch in wal_collect_garbage_f could lead to issues
even before local space changes became written to 0-th vclock component.
Once replica subscribes, its' gc consumer is set to the vclock, which
the replica sent in subscribe request. This vclock might be incomparable
with xlog vclocks of the master, leading to the same issue of
potentially deleting a needed xlog during gc.

Closes #7584

NO_DOC=bugfix

(cherry picked from commit c63bfb9a)

We hold the following invariant in MVCC: the story at the top of the
history chain is present in index.

If a story is subject to be deleted from index and there is an older story
in the history chain, the older story starts to be at the top of the
history chain and is not present in index, which violates our invariant:
explicitly check for this case when evaluating whether a story can be
garbage collected and add an assertion to check the invariant above is not
violated.

Rollbacked stories need to be handled in a special way: they are
present at the end of some history chains and completely unlinked from
others (which also implies they are not present in the corresponding
indexes).

`memtx_tx_story_full_unlink` is called in two contexts: space deletion, in
which we delete all stories, and garbage collection step — the former case
can break the invariant described above, while the latter must preserve it,
hence add two different functions for the corresponding contexts.

Closes #7490

NO_CHANGELOG=<internal bugfix not user observable>
NO_DOC=<bugfix>

(cherry picked from commit c8eccfbb)

When we rollback a transaction statement, we relink its read trackers
to a newer story in the history chain, if present (6c990a7b), but we do not
handle the case when there is no newer story.

If there is an older story in the history chain, we can relink the
rollbacked story's reader to it, but if the rollbacked story is the
only one left, we need to retain it, because it stores the reader list
needed for conflict resolution — such stories are distinguished by the
rollbacked flag, and there can be no more than one such story located
strictly at the end of a given history chain (which means a story can be
fully unlinked from some indexes and present at the end of others).

There are several nuances we need to account for:

Firstly, such rollbacked stories must be impossible to read from an index:
this is ensured by `memtx_tx_story_is_visible`.

Secondly, rollbacked transactions need to be treated as prepared with
stories that have `add_psn == del_psn`, so that they are correctly deleted
during garbage collection.

After this logical change we have the following partially ordered set over
tuple stories:
———————————————————————————————————————————————————————> serialization time
|- - - - - - - -|— — — — — -|— — — — — |— — — — — — -|— — — — — — — -
| No more than  | Committed | Prepared | In-progress | One dirty
| one rollbacked|           |          |             | story in index
| story         |           |          |             |
|- - - - - - - -|— — — — — -| — — — — —|— — — — — — -|— — — — — — — —

Closes #7343

NO_DOC=bugfix

(cherry picked from commit 56cf737c)

`struct memtx_story` has a `space` field, which is basically used
to identify that a tuple is unlinked from the history chain in
`memtx_tx_index_invisible_count_slow` (though this can be determined by its
presence in the index) and is used to get the space's index in
`memtx_tx_story_link_top` (though it can be  retrieved from the older
story's link field): remove this redundant field.

Needed for #7343

NO_CHANGELOG=<refactoring>
NO_DOC=<refactoring>
NO_TEST=<refactoring>

(cherry picked from commit 55e64a8d)

When a space is deleted, all transactions need to be aborted and all their
stories need to be removed immediately out of order: currently we
artificially rollback statements — instead call this statement
removal to logically distinguish it from rollback. It differs in the sense
that the whole space's tuple history is teared down instead — no more
transaction managing is going to be done as opposed to rollback of an
individual transaction.

Needed for #7343

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactoring

(cherry picked from commit 88203d4f)

Follow `memtx_tx_history_{add, prepare}_{insert, delete}` pattern: split
code responsible for rollbacking addition and deletion of a story into
separate functions.

Needed for #7343

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactorin

(cherry picked from commit 9dd27681)

When a statement gets rollbacked, we need to remove delete statements
attached to the story it adds by relinking them and making them delete an
older story in the history chain: refactor this loop out into a separate
function.

Needed for #7343

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactoring

(cherry picked from commit 1da727f6)

If a statement becomes prepared, the story it adds must be 'sunk' to
the level of prepared stories: refactor this loop into a
separate function.

Needed for #7343

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactoring

(cherry picked from commit b25d3729)

If an update operation tried to insert a new key into a map or an
array which was created by a previous update operation, then the
process would fail an assertion.

That was because the first operation was stored as a bar update.
The second operation tried to branch it assuming that the entire
bar update's JSON path must exist, but it wasn't so for the newly
created part of the path.

The solution is to fallback to branching earlier than the entire
bar path ends, if can see that the next part of the path can't be
found.

Closes #7705

NO_DOC=bugfix

(cherry picked from commit 8425ebfc)

TREE (HASH) index implements `random` method: if the space is empty from
the transaction's perspective, which means we have to return nothing, add
gap tracking of whole range (full scan
tracking), since this result is equivalent to `index:select{}`, otherwise
repeatedly call `random` and clarify result, until we get a non-empty one.
We do not care about performance here, since all operations in context of
transaction management currently have O(number of dirty tuples)
complexity.

Closes #7670

NO_DOC=bugfix

(cherry picked from commit 1b82beb2)

This commit moves the code that gets the index of a random light
record from the memtx hash index implementation to a new light method.
This gives us more freedom of refactoring the light internals without
modifying the code using it.

After this change, LIGHT(pos_valid) isn't needed anymore so it's
inlined in LIGHT(random).

Needed for #7192

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

(cherry picked from commit 76add786)

Since `key_def_merge` sets the merged key definition's unique part count
equal to the new part count, the extra assignment in case the index is not
unique is redundant: remove it.

NO_CHANGELOG=<refactoring>
NO_DOC=<refactoring>
NO_TEST=<refactoring>

(cherry picked from commit 1d6c92e5)

If TREE index `get` result is empty, the key part count is incorrectly
compared to the tree's `cmp_def->part_count`, though it should be compared
with `cmp_def->unique_part_count`. But we can actually assume that by the
time we get to the index's `get` method the part count is equal to the
unique part count (partial keys are rejected and `get` is not
supported for non-unique indexes): change check to correct assertion.

Closes #7685

NO_DOC=<bugfix>

(cherry picked from commit bfcd8ca7)

Replaced assertions, that no one started new elections/promoted while
acquiring limbo, with checks that raft term and limbo term didn't
change. In case they did - don't write DEMOTE/PROMOTE and just release
limbo, because it's already owned/will soon be by someone else.

Closes #7086

NO_DOC=Bugfix

(cherry picked from commit 8ee0e434)