supersedes https://github.com/paritytech/parity-bridges-common/pull/2873

Draft because of couple of TODOs:
- [x] fix remaining TODOs;
- [x] double check that all changes from
https://github.com/paritytech/parity-bridges-common/pull/2873 are
correctly ported;
- [x] create a separate PR (on top of that one or a follow up?) for
https://github.com/paritytech/polkadot-sdk/tree/sv-try-new-bridge-fees;


- [x] fix compilation issues (haven't checked, but there should be
many).

---------

Co-authored-by: Adrian Catangiu <[email protected]>

Fixes https://github.com/paritytech/polkadot-sdk/issues/4206



In #1340 one of the storage types was changed from `Candidates` to
`CandidateList`. Since the actual key includes the hash of this value,
all of the candidates stored here are (a) "missing" and (b) unable to
unreserve their candidacy bond.

This migration kills the storage values and refunds the deposit held for
each candidate.

---------

Signed-off-by: georgepisaltu <[email protected]>
Co-authored-by: georgepisaltu <[email protected]>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: georgepisaltu <[email protected]>

This PR backports `spec_version`, `node_version` bumps and reordering of
the prdocs from the 1.10.0 release branch

The runtime now can provide a number of predefined presets of
`RuntimeGenesisConfig` struct. This presets are intended to be used in
different deployments, e.g.: `local`, `staging`, etc, and should be
included into the corresponding chain-specs.

Having `GenesisConfig` presets in runtime allows to fully decouple node
from runtime types (the problem is described in #1984).

**Summary of changes:**
- The `GenesisBuilder` API was adjusted to enable this functionality
(and provide better naming - #150):
   ```rust
    fn preset_names() -> Vec<PresetId>;
fn get_preset(id: Option<PresetId>) -> Option<serde_json::Value>;
//`None` means default
    fn build_state(value: serde_json::Value);
    pub struct PresetId(Vec<u8>);
   ```

- **Breaking change**: Old `create_default_config` method was removed,
`build_config` was renamed to `build_state`. As a consequence a node
won't be able to interact with genesis config for older runtimes. The
cleanup was made for sake of API simplicity. Also IMO maintaining
compatibility with old API is not so crucial.
- Reference implementation was provided for `substrate-test-runtime` and
`rococo` runtimes. For rococo new
[`genesis_configs_presets`](https://github.com/paritytech/polkadot-sdk/blob/3b41d66b97c5ff0ec4a1989da5ffd8b9f3f588e3/polkadot/runtime/rococo/src/genesis_config_presets.rs#L530)
module was added and is used in `GenesisBuilder`
[_presets-related_](https://github.com/paritytech/polkadot-sdk/blob/3b41d66b97c5ff0ec4a1989da5ffd8b9f3f588e3/polkadot/runtime/rococo/src/lib.rs#L2462-L2485)
methods.

- The `chain-spec-builder` util was also improved and allows to
([_doc_](https://github.com/paritytech/polkadot-sdk/blob/3b41d66b97c5ff0ec4a1989da5ffd8b9f3f588e3/substrate/bin/utils/chain-spec-builder/src/lib.rs#L19)):
   - list presets provided by given runtime (`list-presets`),
- display preset or default config provided by the runtime
(`display-preset`),
   - build chain-spec using named preset (`create ... named-preset`),


- The `ChainSpecBuilder` is extended with
[`with_genesis_config_preset_name`](https://github.com/paritytech/polkadot-sdk/blob/3b41d66b97c5ff0ec4a1989da5ffd8b9f3f588e3/substrate/client/chain-spec/src/chain_spec.rs#L447)
method which allows to build chain-spec using named preset provided by
the runtime. Sample usage on the node side
[here](https://github.com/paritytech/polkadot-sdk/blob/2caffaae803e08a3d5b46c860e8016da023ff4ce/polkadot/node/service/src/chain_spec.rs#L404

).

Implementation of #1984.
fixes: #150
part of: #25

---------

Co-authored-by: Sebastian Kunert <[email protected]>
Co-authored-by: Kian Paimani <[email protected]>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>

Part of https://github.com/paritytech/polkadot-sdk/issues/226 
Related https://github.com/paritytech/polkadot-sdk/issues/1833

- Deprecate `CurrencyAdapter` and introduce `FungibleAdapter`
- Deprecate `ToStakingPot` and replace usage with `ResolveTo`
- Required creating a new `StakingPotAccountId` struct that implements
`TypedGet` for the staking pot account ID
- Update parachain common utils `DealWithFees`, `ToAuthor` and
`AssetsToBlockAuthor` implementations to use `fungible`
- Update runtime XCM Weight Traders to use `ResolveTo` instead of
`ToStakingPot`
- Update runtime Transaction Payment pallets to use `FungibleAdapter`
instead of `CurrencyAdapter`
- [x] Blocked by https://github.com/paritytech/polkadot-sdk/pull/1296,
needs the `Unbalanced::decrease_balance` fix

Enables pov-reclaim on the rococo/westend parachains, part of
https://github.com/paritytech/polkadot-sdk/issues/3622

This will make it possible to use remaining weight on idle for
processing enqueued messages.
More context here https://github.com/paritytech/polkadot-sdk/issues/3709



---------

Co-authored-by: Adrian Catangiu <[email protected]>

This PR backports:
- node version bump
- `spec_vesion` bump
- reordering of the `prdocs` to the appropriate folder
from the `1.9.0` release branch

Removed the `pallet::getter` macro call from storage type definitions
and added the corresponding implementations directly.
fixes #3330  

polkadot address: 14JzTPPUd8x8phKi8qLxHgNTnTMg6DUukCLXoWprejkaHXPz

---------

Co-authored-by: Bastian Köcher <[email protected]>

Totally removes the `experimental` feature. Closes #3648.

---------

Co-authored-by: Bastian Köcher <[email protected]>

Step in https://github.com/paritytech/polkadot-sdk/issues/171

This PR removes `as [disambiguation_path]` syntax from `derive_impl`
usage across the polkadot-sdk as introduced in
https://github.com/paritytech/polkadot-sdk/pull/3505

Revert "FRAME: Create `TransactionExtension` as a replacement for `SignedExtension` (#2280)" (#3665)

This PR reverts #2280 which introduced `TransactionExtension` to replace
`SignedExtension`.

As a result of the discussion
[here](https://github.com/paritytech/polkadot-sdk/pull/3623#issuecomment-1986789700

),
the changes will be reverted for now with plans to reintroduce the
concept in the future.

---------

Signed-off-by: georgepisaltu <[email protected]>

Closes #2160

First part of [Extrinsic
Horizon](https://github.com/paritytech/polkadot-sdk/issues/2415

)

Introduces a new trait `TransactionExtension` to replace
`SignedExtension`. Introduce the idea of transactions which obey the
runtime's extensions and have according Extension data (né Extra data)
yet do not have hard-coded signatures.

Deprecate the terminology of "Unsigned" when used for
transactions/extrinsics owing to there now being "proper" unsigned
transactions which obey the extension framework and "old-style" unsigned
which do not. Instead we have __*General*__ for the former and
__*Bare*__ for the latter. (Ultimately, the latter will be phased out as
a type of transaction, and Bare will only be used for Inherents.)

Types of extrinsic are now therefore:
- Bare (no hardcoded signature, no Extra data; used to be known as
"Unsigned")
- Bare transactions (deprecated): Gossiped, validated with
`ValidateUnsigned` (deprecated) and the `_bare_compat` bits of
`TransactionExtension` (deprecated).
  - Inherents: Not gossiped, validated with `ProvideInherent`.
- Extended (Extra data): Gossiped, validated via `TransactionExtension`.
  - Signed transactions (with a hardcoded signature).
  - General transactions (without a hardcoded signature).

`TransactionExtension` differs from `SignedExtension` because:
- A signature on the underlying transaction may validly not be present.
- It may alter the origin during validation.
- `pre_dispatch` is renamed to `prepare` and need not contain the checks
present in `validate`.
- `validate` and `prepare` is passed an `Origin` rather than a
`AccountId`.
- `validate` may pass arbitrary information into `prepare` via a new
user-specifiable type `Val`.
- `AdditionalSigned`/`additional_signed` is renamed to
`Implicit`/`implicit`. It is encoded *for the entire transaction* and
passed in to each extension as a new argument to `validate`. This
facilitates the ability of extensions to acts as underlying crypto.

There is a new `DispatchTransaction` trait which contains only default
function impls and is impl'ed for any `TransactionExtension` impler. It
provides several utility functions which reduce some of the tedium from
using `TransactionExtension` (indeed, none of its regular functions
should now need to be called directly).

Three transaction version discriminator ("versions") are now
permissible:
- 0b000000100: Bare (used to be called "Unsigned"): contains Signature
or Extra (extension data). After bare transactions are no longer
supported, this will strictly identify an Inherents only.
- 0b100000100: Old-school "Signed" Transaction: contains Signature and
Extra (extension data).
- 0b010000100: New-school "General" Transaction: contains Extra
(extension data), but no Signature.

For the New-school General Transaction, it becomes trivial for authors
to publish extensions to the mechanism for authorizing an Origin, e.g.
through new kinds of key-signing schemes, ZK proofs, pallet state,
mutations over pre-authenticated origins or any combination of the
above.

## Code Migration

### NOW: Getting it to build

Wrap your `SignedExtension`s in `AsTransactionExtension`. This should be
accompanied by renaming your aggregate type in line with the new
terminology. E.g. Before:

```rust
/// The SignedExtension to the basic transaction logic.
pub type SignedExtra = (
	/* snip */
	MySpecialSignedExtension,
);
/// Unchecked extrinsic type as expected by this runtime.
pub type UncheckedExtrinsic =
	generic::UncheckedExtrinsic<Address, RuntimeCall, Signature, SignedExtra>;
```

After:

```rust
/// The extension to the basic transaction logic.
pub type TxExtension = (
	/* snip */
	AsTransactionExtension<MySpecialSignedExtension>,
);
/// Unchecked extrinsic type as expected by this runtime.
pub type UncheckedExtrinsic =
	generic::UncheckedExtrinsic<Address, RuntimeCall, Signature, TxExtension>;
```

You'll also need to alter any transaction building logic to add a
`.into()` to make the conversion happen. E.g. Before:

```rust
fn construct_extrinsic(
		/* snip */
) -> UncheckedExtrinsic {
	let extra: SignedExtra = (
		/* snip */
		MySpecialSignedExtension::new(/* snip */),
	);
	let payload = SignedPayload::new(call.clone(), extra.clone()).unwrap();
	let signature = payload.using_encoded(|e| sender.sign(e));
	UncheckedExtrinsic::new_signed(
		/* snip */
		Signature::Sr25519(signature),
		extra,
	)
}
```

After:

```rust
fn construct_extrinsic(
		/* snip */
) -> UncheckedExtrinsic {
	let tx_ext: TxExtension = (
		/* snip */
		MySpecialSignedExtension::new(/* snip */).into(),
	);
	let payload = SignedPayload::new(call.clone(), tx_ext.clone()).unwrap();
	let signature = payload.using_encoded(|e| sender.sign(e));
	UncheckedExtrinsic::new_signed(
		/* snip */
		Signature::Sr25519(signature),
		tx_ext,
	)
}
```

### SOON: Migrating to `TransactionExtension`

Most `SignedExtension`s can be trivially converted to become a
`TransactionExtension`. There are a few things to know.

- Instead of a single trait like `SignedExtension`, you should now
implement two traits individually: `TransactionExtensionBase` and
`TransactionExtension`.
- Weights are now a thing and must be provided via the new function `fn
weight`.

#### `TransactionExtensionBase`

This trait takes care of anything which is not dependent on types
specific to your runtime, most notably `Call`.

- `AdditionalSigned`/`additional_signed` is renamed to
`Implicit`/`implicit`.
- Weight must be returned by implementing the `weight` function. If your
extension is associated with a pallet, you'll probably want to do this
via the pallet's existing benchmarking infrastructure.

#### `TransactionExtension`

Generally:
- `pre_dispatch` is now `prepare` and you *should not reexecute the
`validate` functionality in there*!
- You don't get an account ID any more; you get an origin instead. If
you need to presume an account ID, then you can use the trait function
`AsSystemOriginSigner::as_system_origin_signer`.
- You get an additional ticket, similar to `Pre`, called `Val`. This
defines data which is passed from `validate` into `prepare`. This is
important since you should not be duplicating logic from `validate` to
`prepare`, you need a way of passing your working from the former into
the latter. This is it.
- This trait takes two type parameters: `Call` and `Context`. `Call` is
the runtime call type which used to be an associated type; you can just
move it to become a type parameter for your trait impl. `Context` is not
currently used and you can safely implement over it as an unbounded
type.
- There's no `AccountId` associated type any more. Just remove it.

Regarding `validate`:
- You get three new parameters in `validate`; all can be ignored when
migrating from `SignedExtension`.
- `validate` returns a tuple on success; the second item in the tuple is
the new ticket type `Self::Val` which gets passed in to `prepare`. If
you use any information extracted during `validate` (off-chain and
on-chain, non-mutating) in `prepare` (on-chain, mutating) then you can
pass it through with this. For the tuple's last item, just return the
`origin` argument.

Regarding `prepare`:
- This is renamed from `pre_dispatch`, but there is one change:
- FUNCTIONALITY TO VALIDATE THE TRANSACTION NEED NOT BE DUPLICATED FROM
`validate`!!
- (This is different to `SignedExtension` which was required to run the
same checks in `pre_dispatch` as in `validate`.)

Regarding `post_dispatch`:
- Since there are no unsigned transactions handled by
`TransactionExtension`, `Pre` is always defined, so the first parameter
is `Self::Pre` rather than `Option<Self::Pre>`.

If you make use of `SignedExtension::validate_unsigned` or
`SignedExtension::pre_dispatch_unsigned`, then:
- Just use the regular versions of these functions instead.
- Have your logic execute in the case that the `origin` is `None`.
- Ensure your transaction creation logic creates a General Transaction
rather than a Bare Transaction; this means having to include all
`TransactionExtension`s' data.
- `ValidateUnsigned` can still be used (for now) if you need to be able
to construct transactions which contain none of the extension data,
however these will be phased out in stage 2 of the Transactions Horizon,
so you should consider moving to an extension-centric design.

## TODO

- [x] Introduce `CheckSignature` impl of `TransactionExtension` to
ensure it's possible to have crypto be done wholly in a
`TransactionExtension`.
- [x] Deprecate `SignedExtension` and move all uses in codebase to
`TransactionExtension`.
  - [x] `ChargeTransactionPayment`
  - [x] `DummyExtension`
  - [x] `ChargeAssetTxPayment` (asset-tx-payment)
  - [x] `ChargeAssetTxPayment` (asset-conversion-tx-payment)
  - [x] `CheckWeight`
  - [x] `CheckTxVersion`
  - [x] `CheckSpecVersion`
  - [x] `CheckNonce`
  - [x] `CheckNonZeroSender`
  - [x] `CheckMortality`
  - [x] `CheckGenesis`
  - [x] `CheckOnlySudoAccount`
  - [x] `WatchDummy`
  - [x] `PrevalidateAttests`
  - [x] `GenericSignedExtension`
  - [x] `SignedExtension` (chain-polkadot-bulletin)
  - [x] `RefundSignedExtensionAdapter`
- [x] Implement `fn weight` across the board.
- [ ] Go through all pre-existing extensions which assume an account
signer and explicitly handle the possibility of another kind of origin.
- [x] `CheckNonce` should probably succeed in the case of a non-account
origin.
- [x] `CheckNonZeroSender` should succeed in the case of a non-account
origin.
- [x] `ChargeTransactionPayment` and family should fail in the case of a
non-account origin.
  - [ ] 
- [x] Fix any broken tests.

---------

Signed-off-by: georgepisaltu <[email protected]>
Signed-off-by: Alexandru Vasile <[email protected]>
Signed-off-by: dependabot[bot] <[email protected]>
Signed-off-by: Oliver Tale-Yazdi <[email protected]>
Signed-off-by: Alexandru Gheorghe <[email protected]>
Signed-off-by: Andrei Sandu <[email protected]>
Co-authored-by: Nikhil Gupta <[email protected]>
Co-authored-by: georgepisaltu <[email protected]>
Co-authored-by: Chevdor <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Maciej <[email protected]>
Co-authored-by: Javier Viola <[email protected]>
Co-authored-by: Marcin S. <[email protected]>
Co-authored-by: Tsvetomir Dimitrov <[email protected]>
Co-authored-by: Javier Bullrich <[email protected]>
Co-authored-by: Koute <[email protected]>
Co-authored-by: Adrian Catangiu <[email protected]>
Co-authored-by: Vladimir Istyufeev <[email protected]>
Co-authored-by: Ross Bulat <[email protected]>
Co-authored-by: Gonçalo Pestana <[email protected]>
Co-authored-by: Liam Aharon <[email protected]>
Co-authored-by: Svyatoslav Nikolsky <[email protected]>
Co-authored-by: André Silva <[email protected]>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: s0me0ne-unkn0wn <[email protected]>
Co-authored-by: ordian <[email protected]>
Co-authored-by: Sebastian Kunert <[email protected]>
Co-authored-by: Aaro Altonen <[email protected]>
Co-authored-by: Dmitry Markin <[email protected]>
Co-authored-by: Alexandru Vasile <[email protected]>
Co-authored-by: Alexander Samusev <[email protected]>
Co-authored-by: Julian Eager <[email protected]>
Co-authored-by: Michal Kucharczyk <[email protected]>
Co-authored-by: Davide Galassi <[email protected]>
Co-authored-by: Dónal Murray <[email protected]>
Co-authored-by: yjh <[email protected]>
Co-authored-by: Tom Mi <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Will | Paradox | ParaNodes.io <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Joshy Orndorff <[email protected]>
Co-authored-by: Joshy Orndorff <[email protected]>
Co-authored-by: PG Herveou <[email protected]>
Co-authored-by: Alexander Theißen <[email protected]>
Co-authored-by: Kian Paimani <[email protected]>
Co-authored-by: Juan Girini <[email protected]>
Co-authored-by: bader y <[email protected]>
Co-authored-by: James Wilson <[email protected]>
Co-authored-by: joe petrowski <[email protected]>
Co-authored-by: asynchronous rob <[email protected]>
Co-authored-by: Parth <[email protected]>
Co-authored-by: Andrew Jones <[email protected]>
Co-authored-by: Jonathan Udd <[email protected]>
Co-authored-by: Serban Iorga <[email protected]>
Co-authored-by: Egor_P <[email protected]>
Co-authored-by: Branislav Kontur <[email protected]>
Co-authored-by: Evgeny Snitko <[email protected]>
Co-authored-by: Just van Stam <[email protected]>
Co-authored-by: Francisco Aguirre <[email protected]>
Co-authored-by: gupnik <[email protected]>
Co-authored-by: dzmitry-lahoda <[email protected]>
Co-authored-by: zhiqiangxu <[email protected]>
Co-authored-by: Nazar Mokrynskyi <[email protected]>
Co-authored-by: Anwesh <[email protected]>
Co-authored-by: cheme <[email protected]>
Co-authored-by: Sam Johnson <[email protected]>
Co-authored-by: kianenigma <[email protected]>
Co-authored-by: Jegor Sidorenko <[email protected]>
Co-authored-by: Muharem <[email protected]>
Co-authored-by: joepetrowski <[email protected]>
Co-authored-by: Alexandru Gheorghe <[email protected]>
Co-authored-by: Gabriel Facco de Arruda <[email protected]>
Co-authored-by: Squirrel <[email protected]>
Co-authored-by: Andrei Sandu <[email protected]>
Co-authored-by: georgepisaltu <[email protected]>
Co-authored-by: command-bot <>

This PR backports Node version and `spec_version` bumps to `1.8.0` from
the latest release and orders prdoc files related to it.

If an XCM execution fails or ends with leftover assets, these will be
trapped.
In order to claim them, a custom XCM has to be executed, with the
`ClaimAsset` instruction.
However, arbitrary XCM execution is not allowed everywhere yet and XCM
itself is still not easy enough to use for users out there with trapped
assets.
This new extrinsic in `pallet-xcm` will allow these users to easily
claim their assets, without concerning themselves with writing arbitrary
XCMs.

Part of fixing https://github.com/paritytech/polkadot-sdk/issues/3495



---------

Co-authored-by: command-bot <>
Co-authored-by: Adrian Catangiu <[email protected]>

This MR is the merge of
https://github.com/paritytech/substrate/pull/14414 and
https://github.com/paritytech/substrate/pull/14275. It implements
[RFC#13](https://github.com/polkadot-fellows/RFCs/pull/13), closes
https://github.com/paritytech/polkadot-sdk/issues/198.

----- 

This Merge request introduces three major topicals:

1. Multi-Block-Migrations
1. New pallet `poll` hook for periodic service work
1. Replacement hooks for `on_initialize` and `on_finalize` in cases
where `poll` cannot be used

and some more general changes to FRAME.  
The changes for each topical span over multiple crates. They are listed
in topical order below.

# 1.) Multi-Block-Migrations

Multi-Block-Migrations are facilitated by creating `pallet_migrations`
and configuring `System::Config::MultiBlockMigrator` to point to it.
Executive picks this up and triggers one step of the migrations pallet
per block.
The chain is in lockdown mode for as long as an MBM is ongoing.
Executive does this by polling `MultiBlockMigrator::ongoing` and not
allowing any transaction in a block, if true.

A MBM is defined through trait `SteppedMigration`. A condensed version
looks like this:
```rust
/// A migration that can proceed in multiple steps.
pub trait SteppedMigration {
	type Cursor: FullCodec + MaxEncodedLen;
	type Identifier: FullCodec + MaxEncodedLen;

	fn id() -> Self::Identifier;

	fn max_steps() -> Option<u32>;

	fn step(
		cursor: Option<Self::Cursor>,
		meter: &mut WeightMeter,
	) -> Result<Option<Self::Cursor>, SteppedMigrationError>;
}
```

`pallet_migrations` can be configured with an aggregated tuple of these
migrations. It then starts to migrate them one-by-one on the next
runtime upgrade.
Two things are important here:
- 1. Doing another runtime upgrade while MBMs are ongoing is not a good
idea and can lead to messed up state.
- 2. **Pallet Migrations MUST BE CONFIGURED IN `System::Config`,
otherwise it is not used.**

The pallet supports an `UpgradeStatusHandler` that can be used to notify
external logic of upgrade start/finish (for example to pause XCM
dispatch).

Error recovery is very limited in the case that a migration errors or
times out (exceeds its `max_steps`). Currently the runtime dev can
decide in `FailedMigrationHandler::failed` how to handle this. One
follow-up would be to pair this with the `SafeMode` pallet and enact
safe mode when an upgrade fails, to allow governance to rescue the
chain. This is currently not possible, since governance is not
`Mandatory`.

## Runtime API

- `Core`: `initialize_block` now returns `ExtrinsicInclusionMode` to
inform the Block Author whether they can push transactions.

### Integration

Add it to your runtime implementation of `Core` and `BlockBuilder`:
```patch
diff --git a/runtime/src/lib.rs b/runtime/src/lib.rs
@@ impl_runtime_apis! {
	impl sp_block_builder::Core<Block> for Runtime {
-		fn initialize_block(header: &<Block as BlockT>::Header) {
+		fn initialize_block(header: &<Block as BlockT>::Header) -> RuntimeExecutiveMode {
			Executive::initialize_block(header)
		}

		...
	}
```

# 2.) `poll` hook

A new pallet hook is introduced: `poll`. `Poll` is intended to replace
mostly all usage of `on_initialize`.
The reason for this is that any code that can be called from
`on_initialize` cannot be migrated through an MBM. Currently there is no
way to statically check this; the implication is to use `on_initialize`
as rarely as possible.
Failing to do so can result in broken storage invariants.

The implementation of the poll hook depends on the `Runtime API` changes
that are explained above.

# 3.) Hard-Deadline callbacks

Three new callbacks are introduced and configured on `System::Config`:
`PreInherents`, `PostInherents` and `PostTransactions`.
These hooks are meant as replacement for `on_initialize` and
`on_finalize` in cases where the code that runs cannot be moved to
`poll`.
The reason for this is to make the usage of HD-code (hard deadline) more
explicit - again to prevent broken invariants by MBMs.

# 4.) FRAME (general changes)

## `frame_system` pallet

A new memorize storage item `InherentsApplied` is added. It is used by
executive to track whether inherents have already been applied.
Executive and can then execute the MBMs directly between inherents and
transactions.

The `Config` gets five new items:
- `SingleBlockMigrations` this is the new way of configuring migrations
that run in a single block. Previously they were defined as last generic
argument of `Executive`. This shift is brings all central configuration
about migrations closer into view of the developer (migrations that are
configured in `Executive` will still work for now but is deprecated).
- `MultiBlockMigrator` this can be configured to an engine that drives
MBMs. One example would be the `pallet_migrations`. Note that this is
only the engine; the exact MBMs are injected into the engine.
- `PreInherents` a callback that executes after `on_initialize` but
before inherents.
- `PostInherents` a callback that executes after all inherents ran
(including MBMs and `poll`).
- `PostTransactions` in symmetry to `PreInherents`, this one is called
before `on_finalize` but after all transactions.

A sane default is to set all of these to `()`. Example diff suitable for
any chain:
```patch
@@ impl frame_system::Config for Test {
 	type MaxConsumers = ConstU32<16>;
+	type SingleBlockMigrations = ();
+	type MultiBlockMigrator = ();
+	type PreInherents = ();
+	type PostInherents = ();
+	type PostTransactions = ();
 }
```

An overview of how the block execution now looks like is here. The same
graph is also in the rust doc.

<details><summary>Block Execution Flow</summary>
<p>

![Screenshot 2023-12-04 at 19 11
29](https://github.com/paritytech/polkadot-sdk/assets/10380170/e88a80c4-ef11-4faa-8df5-8b33a724c054)

</p>
</details> 

## Inherent Order

Moved to https://github.com/paritytech/polkadot-sdk/pull/2154



---------------


## TODO

- [ ] Check that `try-runtime` still works
- [ ] Ensure backwards compatibility with old Runtime APIs
- [x] Consume weight correctly
- [x] Cleanup

---------

Signed-off-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: Liam Aharon <[email protected]>
Co-authored-by: Juan Girini <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: Francisco Aguirre <[email protected]>
Co-authored-by: Gavin Wood <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>

Closes https://github.com/paritytech/polkadot-sdk-docs/issues/55

- Changes 'current storage version' terminology to less ambiguous
'in-code storage version' (suggestion by @ggwpez)
- Adds a new example pallet `pallet-example-single-block-migrations`
- Adds a new reference doc to replace
https://docs.substrate.io/maintain/runtime-upgrades/ (temporarily living
in the pallet while we wait for developer hub PR to merge)
- Adds documentation for the `storage_alias` macro
- Improves `trait Hooks` docs 
- Improves `trait GetStorageVersion` docs
- Update the suggested patterns for using `VersionedMigration`, so that
version unchecked migrations are never exported
- Prevents accidental usage of version unchecked migrations in runtimes

https://github.com/paritytech/substrate/pull/14421#discussion_r1255467895
- Unversioned migration code is kept inside `mod version_unchecked`,
versioned code is kept in `pub mod versioned`
- It is necessary to use modules to limit visibility because the inner
migration must be `pub`. See
https://github.com/rust-lang/rust/issues/30905 and

https://internals.rust-lang.org/t/lang-team-minutes-private-in-public-rules/4504/40
for more.

### todo

- [x] move to reference docs to proper place within sdk-docs (now that
https://github.com/paritytech/polkadot-sdk/pull/2102

 is merged)
- [x] prdoc

---------

Co-authored-by: Kian Paimani <[email protected]>
Co-authored-by: Juan <[email protected]>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: gupnik <[email protected]>

## Problem
During the bumping of the `polkadot-fellows` repository to
`[email protected]`, I encountered a situation where the benchmarks
`teleport_assets` and `reserve_transfer_assets` in AssetHubKusama
started to fail. This issue arose due to a decreased ED balance for
AssetHubs introduced
[here](https://github.com/polkadot-fellows/runtimes/pull/158/files#diff-80668ff8e793b64f36a9a3ec512df5cbca4ad448c157a5d81abda1b15f35f1daR213),
and also because of a [missing CI
pipeline](https://github.com/polkadot-fellows/runtimes/issues/197) to
check the benchmarks, which went unnoticed.

These benchmarks expect the `caller` to have enough:
1. balance to transfer (BTT)
2. balance for paying delivery (BFPD).
 
So the initial balance was calculated as `ED * 100`, which seems
reasonable:
```
const ED_MULTIPLIER: u32 = 100;
let balance = existential_deposit.saturating_mul(ED_MULTIPLIER.into());`
```
The problem arises when the price for delivery is 100 times higher than
the existential deposit. In other words, when `ED * 100` does not cover
`BTT` + `BFPD`.

I check AHR/AHW/AHK/AHP and this problem has only AssetHubKusama
```
ED: 3333333
calculated price to parent delivery:  1031666634  (from xcm logs from the benchmark)
---

3333333 * 100 - BTT(3333333) - BFPD(1031666634) = −701666667
```
which results in the error;
```
2024-02-23 09:19:42 Unable to charge fee with error Module(ModuleError { index: 31, error: [17, 0, 0, 0], message: Some("FeesNotMet") })
Error: Input("Benchmark pallet_xcm::reserve_transfer_assets failed: FeesNotMet")
     
```

## Solution

The benchmarks `teleport_assets` and `reserve_transfer_assets` were
fixed by removing `ED * 100` and replacing it with `DeliveryHelper`
logic, which calculates the (almost real) price for delivery and sets it
along with the existential deposit as the initial balance for the
account used in the benchmark.


## TODO

- [ ] patch for 1.6 -
https://github.com/paritytech/polkadot-sdk/pull/3466
- [ ] patch for 1.7 -
https://github.com/paritytech/polkadot-sdk/pull/3465


- [ ] patch for 1.8 - TODO: PR

---------

Co-authored-by: Francisco Aguirre <[email protected]>

This PR backports version bumps from `1.7.0` release branch and moves
related prdoc files to the appropriate folder.

Relates to: https://github.com/paritytech/polkadot-sdk/issues/3214

## TODO

- [ ] backport to the `1.7.0` release

Built on top of https://github.com/paritytech/polkadot-sdk/pull/2826/
which was a trial run.

Guide:
https://github.com/w3f/polkadot-wiki/blob/master/docs/maintain/maintain-guides-async-backing.md



---------

Signed-off-by: georgepisaltu <[email protected]>
Co-authored-by: Branislav Kontur <[email protected]>
Co-authored-by: Dónal Murray <[email protected]>
Co-authored-by: Dmitry Sinyavin <[email protected]>
Co-authored-by: s0me0ne-unkn0wn <[email protected]>
Co-authored-by: Svyatoslav Nikolsky <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: georgepisaltu <[email protected]>

[frame] `#[pallet::composite_enum]` improved variant count handling + removed `pallet_balances`'s `MaxHolds` config (#2657)

I started this investigation/issue based on @liamaharon question
[here](https://github.com/paritytech/polkadot-sdk/pull/1801#discussion_r1410452499).

## Problem

The `pallet_balances` integrity test should correctly detect that the
runtime has correct distinct `HoldReasons` variant count. I assume the
same situation exists for RuntimeFreezeReason.

It is not a critical problem, if we set `MaxHolds` with a sufficiently
large value, everything should be ok. However, in this case, the
integrity_test check becomes less useful.

**Situation for "any" runtime:**
- `HoldReason` enums from different pallets:
```rust
        /// from pallet_nis
        #[pallet::composite_enum]
	pub enum HoldReason {
		NftReceipt,
	}

        /// from pallet_preimage
        #[pallet::composite_enum]
	pub enum HoldReason {
		Preimage,
	}

        // from pallet_state-trie-migration
        #[pallet::composite_enum]
	pub enum HoldReason {
		SlashForContinueMigrate,
		SlashForMigrateCustomTop,
		SlashForMigrateCustomChild,
	}
```

- generated `RuntimeHoldReason` enum looks like:
```rust
pub enum RuntimeHoldReason {

    #[codec(index = 32u8)]
    Preimage(pallet_preimage::HoldReason),

    #[codec(index = 38u8)]
    Nis(pallet_nis::HoldReason),

    #[codec(index = 42u8)]
    StateTrieMigration(pallet_state_trie_migration::HoldReason),
}
```

- composite enum `RuntimeHoldReason` variant count is detected as `3`
- we set `type MaxHolds = ConstU32<3>`
- `pallet_balances::integrity_test` is ok with `3`(at least 3)

However, the real problem can occur in a live runtime where some
functionality might stop working. This is due to a total of 5 distinct
hold reasons (for pallets with multi-instance support, it is even more),
and not all of them can be used because of an incorrect `MaxHolds`,
which is deemed acceptable according to the `integrity_test`:
  ```
  // pseudo-code - if we try to call all of these:

T::Currency::hold(&pallet_nis::HoldReason::NftReceipt.into(),
&nft_owner, deposit)?;
T::Currency::hold(&pallet_preimage::HoldReason::Preimage.into(),
&nft_owner, deposit)?;

T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForContinueMigrate.into(),
&nft_owner, deposit)?;

  // With `type MaxHolds = ConstU32<3>` these two will fail

T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForMigrateCustomTop.into(),
&nft_owner, deposit)?;

T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForMigrateCustomChild.into(),
&nft_owner, deposit)?;
  ```  


## Solutions

A macro `#[pallet::*]` expansion is extended of `VariantCount`
implementation for the `#[pallet::composite_enum]` enum type. This
expansion generates the `VariantCount` implementation for pallets'
`HoldReason`, `FreezeReason`, `LockId`, and `SlashReason`. Enum variants
must be plain enum values without fields to ensure a deterministic
count.

The composite runtime enum, `RuntimeHoldReason` and
`RuntimeFreezeReason`, now sets `VariantCount::VARIANT_COUNT` as the sum
of pallets' enum `VariantCount::VARIANT_COUNT`:
```rust
#[frame_support::pallet(dev_mode)]
mod module_single_instance {

	#[pallet::composite_enum]
	pub enum HoldReason {
		ModuleSingleInstanceReason1,
		ModuleSingleInstanceReason2,
	}
...
}

#[frame_support::pallet(dev_mode)]
mod module_multi_instance {

	#[pallet::composite_enum]
	pub enum HoldReason<I: 'static = ()> {
		ModuleMultiInstanceReason1,
		ModuleMultiInstanceReason2,
		ModuleMultiInstanceReason3,
	}
...
}


impl self::sp_api_hidden_includes_construct_runtime::hidden_include::traits::VariantCount
    for RuntimeHoldReason
{
    const VARIANT_COUNT: u32 = 0
        + module_single_instance::HoldReason::VARIANT_COUNT
        + module_multi_instance::HoldReason::<module_multi_instance::Instance1>::VARIANT_COUNT
        + module_multi_instance::HoldReason::<module_multi_instance::Instance2>::VARIANT_COUNT
        + module_multi_instance::HoldReason::<module_multi_instance::Instance3>::VARIANT_COUNT;
}
```

In addition, `MaxHolds` is removed (as suggested
[here](https://github.com/paritytech/polkadot-sdk/pull/2657#discussion_r1443324573))
from `pallet_balances`, and its `Holds` are now bounded to
`RuntimeHoldReason::VARIANT_COUNT`. Therefore, there is no need to let
the runtime specify `MaxHolds`.


## For reviewers

Relevant changes can be found here:
- `substrate/frame/support/procedural/src/lib.rs` 
-  `substrate/frame/support/procedural/src/pallet/parse/composite.rs`
-  `substrate/frame/support/procedural/src/pallet/expand/composite.rs`
-
`substrate/frame/support/procedural/src/construct_runtime/expand/composite_helper.rs`
-
`substrate/frame/support/procedural/src/construct_runtime/expand/hold_reason.rs`
-
`substrate/frame/support/procedural/src/construct_runtime/expand/freeze_reason.rs`
- `substrate/frame/support/src/traits/misc.rs`

And the rest of the files is just about removed `MaxHolds` from
`pallet_balances`

## Next steps

Do the same for `MaxFreezes`
https://github.com/paritytech/polkadot-sdk/issues/2997

.

---------

Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Dónal Murray <[email protected]>
Co-authored-by: gupnik <[email protected]>

The `parachains-common` contains a lots of constants and type
definitions which are used for `polkadot-sdk`'s testnet runtimes and
also for `polkadot-fellows`'s production [SP
runtimes](https://github.com/polkadot-fellows/runtimes/tree/main/system-parachains/constants).
This PR cleans `parachains-common` module to contain only common and
generic functionality.

Testnet-specific constants have been moved to the separate module
dedicated just for testnets:
`polkadot-sdk/cumulus/parachains/runtimes/constants/`


Part of: https://github.com/paritytech/polkadot-sdk/issues/3054



---------

Co-authored-by: georgepisaltu <[email protected]>

Reverts paritytech/polkadot-sdk#2302. 🤦‍♂️ should have checked the
migration CI first.

We either need to reduce the `max_message_size` for the open HRMP
channels on the failing chains or increase the `PageSize` of the XCMP
queue.
Both would be fine on a test-net, but i assume this will also fail
before the next SP runtime upgrade so first need to think what best to
do.
AFAIK its not possible currently to change the `max_message_size` of an
open HRMP channel.

Remove `without_storage_info` from the XCMP queue pallet. Part of
https://github.com/paritytech/polkadot-sdk/issues/323



Changes:
- Limit the number of channels that can be suspended at the same time.
- Limit the number of channels that can have messages or signals pending
at the same time.

A No-OP migration is put in place to ensure that all `BoundedVec`s still
decode and not truncate after upgrade. The storage version is thereby
bumped to 4 to have our tooling remind us to deploy that migration.

---------

Signed-off-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: Francisco Aguirre <[email protected]>

Moved from: https://github.com/paritytech/polkadot/pull/6951

closes https://github.com/paritytech/polkadot-sdk/issues/490

- [x] update cumulus

--- 
This PR introduces transactional processing of certain xcm instructions.
For the list of instructions checkout
https://github.com/paritytech/polkadot-sdk/issues/490. The transactional
processing is implemented as an xcm-executor config item. The two
implementations in this PR are `FrameTransactionalProcessor` and `()`.
The `()` implementation does no transactional processing. Each
implementation of the `ProcessTransaction` trait has an
`IS_TRANSACTIONAL` const that tells the XCVM if transactional processing
is actually implemented. If Transactional processing is implemented,
changes to touched registers should also be rolled back to prevent
inconsistencies.


Note for reviewers:
Check out the following safety assumption:
https://github.com/paritytech/polkadot-sdk/pull/1222/files#diff-4effad7d8c1c9de19fd27e18661cbf2128c8718f3b2420a27d2f816e0749ea53R30



---------

Co-authored-by: Keith Yeung <[email protected]>
Co-authored-by: Francisco Aguirre <[email protected]>
Co-authored-by: command-bot <>

There were several improvements and PRs that didn't apply to all
runtimes, so this PR attempts to align those small differences. In
addition, the PR eliminates unused dependencies across multiple modules.

Relates to PR for `polkadot-fellows`:
https://github.com/polkadot-fellows/runtimes/pull/154

Clean up all the old syntax.

---------

Co-authored-by: command-bot <>
Co-authored-by: gupnik <[email protected]>
Co-authored-by: Nikhil Gupta <[email protected]>
Co-authored-by: Maksym H <[email protected]>

Update bridges subtree

This PR backports version bumps from release branch
`release-polkadot-v1.6.0` back to `master` and also moved `prdoc` files
related to the release to the appropriate folder

# Note for reviewer

Most changes are just syntax changes necessary for the new version.
Most important files should be the ones under the `xcm` folder.

# Description 

Added XCMv4.

## Removed `Multi` prefix
The following types have been renamed:
- MultiLocation -> Location
- MultiAsset -> Asset
- MultiAssets -> Assets
- InteriorMultiLocation -> InteriorLocation
- MultiAssetFilter -> AssetFilter
- VersionedMultiAsset -> VersionedAsset
- WildMultiAsset -> WildAsset
- VersionedMultiLocation -> VersionedLocation

In order to fix a name conflict, the `Assets` in `xcm-executor` were
renamed to `HoldingAssets`, as they represent assets in holding.

## Removed `Abstract` asset id

It was not being used anywhere and this simplifies the code.

Now assets are just constructed as follows:

```rust
let asset: Asset = (AssetId(Location::new(1, Here)), 100u128).into();
```

No need for specifying `Concrete` anymore.

## Outcome is now a named fields struct

Instead of

```rust
pub enum Outcome {
  Complete(Weight),
  Incomplete(Weight, Error),
  Error(Error),
}
```

we now have

```rust
pub enum Outcome {
  Complete { used: Weight },
  Incomplete { used: Weight, error: Error },
  Error { error: Error },
}
```

## Added Reanchorable trait

Now both locations and assets implement this trait, making it easier to
reanchor both.

## New syntax for building locations and junctions

Now junctions are built using the following methods:

```rust
let location = Location {
    parents: 1,
    interior: [Parachain(1000), PalletInstance(50), GeneralIndex(1984)].into()
};
```

or

```rust
let location = Location::new(1, [Parachain(1000), PalletInstance(50), GeneralIndex(1984)]);
```

And they are matched like so:

```rust
match location.unpack() {
  (1, [Parachain(id)]) => ...
  (0, Here) => ...,
  (1, [_]) => ...,
}
```

This syntax is mandatory in v4, and has been also implemented for v2 and
v3 for easier migration.

This was needed to make all sizes smaller.

# TODO
- [x] Scaffold v4
- [x] Port github.com/paritytech/polkadot/pull/7236
- [x] Remove `Multi` prefix
- [x] Remove `Abstract` asset id

---------

Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <[email protected]>

# Description

Adds Snowbridge to the Rococo bridge hub runtime. Includes config
changes required in Rococo asset hub.

---------

Co-authored-by: Alistair Singh <[email protected]>
Co-authored-by: ron <[email protected]>
Co-authored-by: Vincent Geddes <[email protected]>
Co-authored-by: claravanstaden <Cats 4 life!>

This PR backports `transaction_version` bump from `1.5.0` release back
to `master`

## Summary

This pull request proposes a solution for improved control of the
versioned XCM flow over the bridge (across different consensus chains)
and resolves the situation where the sending chain/consensus has already
migrated to a higher XCM version than the receiving chain/consensus.

## Problem/Motivation

The current flow over the bridge involves a transfer from AssetHubRococo
(AHR) to BridgeHubRococo (BHR) to BridgeHubWestend (BHW) and finally to
AssetHubWestend (AHW), beginning with a reserve-backed transfer on AHR.

In this process:
1. AHR sends XCM `ExportMessage` through `XcmpQueue`, incorporating XCM
version checks using the `WrapVersion` feature, influenced by
`pallet_xcm::SupportedVersion` (managed by
`pallet_xcm::force_xcm_version` or version discovery).

2. BHR handles the `ExportMessage` instruction, utilizing the latest XCM
version. The `HaulBlobExporter` converts the inner XCM to
[`VersionedXcm::from`](https://github.com/paritytech/polkadot-sdk/blob/63ac2471aa0210f0ac9903bdd7d8f9351f9a635f/polkadot/xcm/xcm-builder/src/universal_exports.rs#L465-L467),
also using the latest XCM version.

However, challenges arise:
- Incompatibility when BHW uses a different version than BHR. For
instance, if BHR migrates to **XCMv4** while BHW remains on **XCMv3**,
BHR's `VersionedXcm::from` uses `VersionedXcm::V4` variant, causing
encoding issues for BHW.
  ```
	/// Just a simulation of possible error, which could happen on BHW
	/// (this code is based on actual master without XCMv4)
	let encoded = hex_literal::hex!("0400");
	println!("{:?}", VersionedXcm::<()>::decode(&mut &encoded[..]));

Err(Error { cause: None, desc: "Could not decode `VersionedXcm`, variant
doesn't exist" })
  ``` 
- Similar compatibility issues exist between AHR and AHW.

## Solution

This pull request introduces the following solutions:

1. **New trait `CheckVersion`** - added to the `xcm` module and exposing
`pallet_xcm::SupportedVersion`. This enhancement allows checking the
actual XCM version for desired destinations outside of the `pallet_xcm`
module.

2. **Version Check in `HaulBlobExporter`** uses `CheckVersion` to check
known/configured destination versions, ensuring compatibility. For
example, in the scenario mentioned, BHR can store the version `3` for
BHW. If BHR is on XCMv4, it will attempt to downgrade the message to
version `3` instead of using the latest version `4`.

3. **Version Check in `pallet-xcm-bridge-hub-router`** - this check
ensures compatibility with the real destination's XCM version,
preventing the unnecessary sending of messages to the local bridge hub
if versions are incompatible.

These additions aim to improve the control and compatibility of XCM
flows over the bridge and addressing issues related to version
mismatches.

## Possible alternative solution

_(More investigation is needed, and at the very least, it should extend
to XCMv4/5. If this proves to be a viable option, I can open an RFC for
XCM.)._

Add the `XcmVersion` attribute to the `ExportMessage` so that the
sending chain can determine, based on what is stored in
`pallet_xcm::SupportedVersion`, the version the destination is using.
This way, we may not need to handle the version in `HaulBlobExporter`.

```
ExportMessage {
	network: NetworkId,
	destination: InteriorMultiLocation,
	xcm: Xcm<()>
	destination_xcm_version: Version, // <- new attritbute
},
```

```
pub trait ExportXcm {
        fn validate(
		network: NetworkId,
		channel: u32,
		universal_source: &mut Option<InteriorMultiLocation>,
		destination: &mut Option<InteriorMultiLocation>,
		message: &mut Option<Xcm<()>>,
                destination_xcm_version: Version, , // <- new attritbute
	) -> SendResult<Self::Ticket>;
```

## Future Directions

This PR does not fix version discovery over bridge, further
investigation will be conducted here:
https://github.com/paritytech/polkadot-sdk/issues/2417.

## TODO

- [x] `pallet_xcm` mock for tests uses hard-coded XCM version `2` -
change to 3 or lastest?
- [x] fix `pallet-xcm-bridge-hub-router`
- [x] fix HaulBlobExporter with version determination
[here](https://github.com/paritytech/polkadot-sdk/blob/2183669d05f9b510f979a0cc3c7847707bacba2e/polkadot/xcm/xcm-builder/src/universal_exports.rs#L465)
- [x] add unit-tests to the runtimes
- [x] run benchmarks for `ExportMessage`
- [x] extend local run scripts about `force_xcm_version(dest, version)`
- [ ] when merged, prepare governance calls for Rococo/Westend
- [ ] add PRDoc

Part of: https://github.com/paritytech/parity-bridges-common/issues/2719

---------

Co-authored-by: command-bot <>

This PR introduces a script and some templates to use the prdoc involved
in a release and build:
- the changelog
- a simple draft of audience documentation

Since the prdoc presence was enforced in the middle of the version
1.5.0, not all PRs did come with a `prdoc` file.
This PR creates all the missing `prdoc` files with some minimum content
allowing to properly generate the changelog.
The generated content is **not** suitable for the audience
documentation.

The audience documentation will be possible with the next version, when
all PR come with a proper `prdoc`.

## Assumptions

- the prdoc files for release `vX.Y.Z` have been moved under
`prdoc/X.Y.Z`
- the changelog requires for now for the prdoc files to contain author +
topic. Thos fields are optional.

The build script can  be called as:
```
VERSION=X.Y.Z ./scripts/release/build-changelogs.sh
```

Related:
-  #1408

---------

Co-authored-by: EgorPopelyaev <[email protected]>

## Summary

This PR aligns Rococo/Westend bridge with latest Bridges repo
development:
- https://github.com/paritytech/parity-bridges-common/pull/2727
- https://github.com/paritytech/parity-bridges-common/pull/2728
- https://github.com/paritytech/parity-bridges-common/pull/2729




Part of: https://github.com/paritytech/parity-bridges-common/issues/2452

# Motivation (+testing)

### Enable easy `ForeignAssets` transfers using `pallet-xcm` 

We had just previously added capabilities to teleport fees during
reserve-based transfers, but what about reserve-transferring fees when
needing to teleport some non-fee asset?

This PR aligns everything under either explicit reserve-transfer,
explicit teleport, or this new flexible `transfer_assets()` which can
mix and match as needed with fewer artificial constraints imposed to the
user.

This will enable, for example, a (non-system) parachain to teleport
their `ForeignAssets` assets to AssetHub while using DOT to pay fees.
(the assets are teleported - as foreign assets should from their owner
chain - while DOT used for fees can only be reserve-based transferred
between said parachain and AssetHub).

Added `xcm-emulator` tests for this scenario ^.

# Description

Reverts `(limited_)reserve_transfer_assets` to only allow reserve-based
transfers for all `assets` including fees.

Similarly `(limited_)teleport_assets` only allows teleports for all
`assets` including fees.
    
For complex combinations of asset transfers where assets and fees may
have different reserves or different reserve/teleport trust
configurations, users can use the newly added `transfer_assets()`
extrinsic which is more flexible in allowing more complex scenarios.

`assets` (excluding `fees`) must have same reserve location or otherwise
be teleportable to `dest`.
No limitations imposed on `fees`.

- for local reserve: transfer assets to sovereign account of destination
chain and forward a notification XCM to `dest` to mint and deposit
reserve-based assets to `beneficiary`.
- for destination reserve: burn local assets and forward a notification
to `dest` chain to withdraw the reserve assets from this chain's
sovereign account and deposit them to `beneficiary`.
- for remote reserve: burn local assets, forward XCM to reserve chain to
move reserves from this chain's SA to `dest` chain's SA, and forward
another XCM to `dest` to mint and deposit reserve-based assets to
`beneficiary`.
- for teleports: burn local assets and forward XCM to `dest` chain to
mint/teleport assets and deposit them to `beneficiary`.

## Review notes

Only around 500 lines are prod code (see `pallet_xcm/src/lib.rs`), the
rest of the PR is new tests and improving existing tests.

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Co-authored-by: command-bot <>