# 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.

---------

Co-authored-by: command-bot <>

Removes obsolete fields from the `QueueConfigData` structure. For the
remaining fields, if they use the old defaults, we replace them with the
new defaults.

Resolves: https://github.com/paritytech/polkadot-sdk/issues/1795

Westend SP dmp queue pallet removal is complete.

<img width="1499" alt="Screenshot 2023-11-28 at 08 31 27"
src="https://github.com/paritytech/polkadot-sdk/assets/16665596/906246fb-3de9-4133-a827-431636a097ad">

<img width="1499" alt="Screenshot 2023-11-28 at 08 32 08"
src="https://github.com/paritytech/polkadot-sdk/assets/16665596/bde84891-b044-42c7-9a0b-59125cd24db1">

<img width="1499" alt="Screenshot 2023-11-28 at 08 31 45"
src="https://github.com/paritytech/polkadot-sdk/assets/16665596/38337484-0856-45c0-b9ff-8c785bc3c0e3">

## Overview

This PR aligns the `spec_version` formatting to the [recent
changes](https://github.com/polkadot-fellows/runtimes/pull/26/files#diff-efa4caeb17487ecb13d8f5eb7863c3241d84afa2e73fbf25909a2ca89df0f362R142)
made for the Polkadot/Kusama runtimes.

It also backports the latest version `v1.4.0` bumps as `1_004_000`.

## Details

During the switch from `v0.9` to `v1.x`, the format of the
`spec_version` was modified from: `(M)m_ppp` for a runtime considered on
version `M.m.pp`. For instance `0.9.42` had a `spec_version` of `9420`.

With the transition to `v1.x`, the format was changed to a bigger number
(still `u32`) formatted as `MM_mm_ppp` where `1.2.3` would be stored as
`01_02_003`.

This PR aligns the format with that has been introduced in the
fellowship repo: `MMM_mmm_ppp`.

---------

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

This PR fixes two things:
- relax `force_default_xcm_version` for testnet system parachains (e.g.
BridgeHubWestend has now 2 and there is no way to change it to 3, so we
need to call `force_xcm_version(3)` for every parachain that it is
connected to, because we send XCMv3 messages)
- add `Storage` item to `PolkadotXcm` pallet definition (now we cannot
see storage items for `pallet_xcm` in PJS)


## TODO

- [ ] when merged open PR to `polkadot-fellows/runtimes` repo

Add collectives and glutton parachain westend runtimes to prepare for
#1737.

The removal of system parachain native runtimes #1737 is blocked until
chainspecs and runtime APIs can be dealt with cleanly (merge of #1256
and follow up PRs).

In the meantime, these additions are ready to be merged to `master`, so
I have separated them out into this PR.

Also marked `bridge-hub-westend` as unimplemented in line with [this
issue](https://github.com/paritytech/parity-bridges-common/issues/2602).

TODO
- [x] add to `command-bot` benchmarks
- [x] add to `command-bot-scripts` benchmarks
- [x] generate weights

---------

Co-authored-by: joe petrowski <[email protected]>
Co-authored-by: Muharem <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: Branislav Kontur <[email protected]>