When the license was added to the repository, its text was changed (some
sections at the end removed) and, worse, the authors of go-ethereum
tried to claim copyright on the license text.

The correct way to apply GPL to a project is to copy it verbatim.
This change reverts the text of the GPL to the original.

* les, les/lespay/server: refactor client pool

* les: use ns.Operation and sub calls where needed

* les: fixed tests

* les: removed active/inactive logic from peerSet

* les: removed active/inactive peer logic

* les: fixed linter warnings

* les: fixed more linter errors and added missing metrics

* les: addressed comments

* cmd/geth: fixed TestPriorityClient

* les: simplified clientPool state machine

* les/lespay/server: do not use goroutine for balance callbacks

* internal/web3ext: fix addBalance required parameters

* les: removed freeCapacity, always connect at minCapacity initially

* les: only allow capacity change with priority status
Co-authored-by: Nrjl493456442 <garyrong0905@gmail.com>

This can be useful when working with raw RLP data.

This PR adds an extra guarantee to NodeStateMachine: it ensures that all
immediate effects of a certain change are processed before any subsequent
effects of any of the immediate effects on the same node. In the original
version, if a cascaded change caused a subscription callback to be called
multiple times for the same node then these calls might have happened in a
wrong chronological order.

For example:

- a subscription to flag0 changes flag1 and flag2
- a subscription to flag1 changes flag3
- a subscription to flag1, flag2 and flag3 was called in the following order:

   [flag1] -> [flag1, flag3]
   [] -> [flag1]
   [flag1, flag3] -> [flag1, flag2, flag3]

This happened because the tree of changes was traversed in a "depth-first
order". Now it is traversed in a "breadth-first order"; each node has a
FIFO queue for pending callbacks and each triggered subscription callback
is added to the end of the list. The already existing guarantees are
retained; no SetState or SetField returns until the callback queue of the
node is empty again. Just like before, it is the responsibility of the
state machine design to ensure that infinite state loops are not possible.
Multiple changes affecting the same node can still happen simultaneously;
in this case the changes can be interleaved in the FIFO of the node but the
correct order is still guaranteed.

A new unit test is also added to verify callback order in the above scenario.

Fixes a regression introduced in #21536

This PR changes several different things:

- Adds test cases for the miner loop
- Stops the worker if it wasn't already stopped in worker.Close()
- Uses channels instead of atomics in the miner.update() loop
Co-authored-by: NFelix Lange <fjl@twurst.com>

* cmd/geth: print warning when whisper config is present in toml

* Update cmd/geth/config.go
Co-authored-by: NMartin Holst Swende <martin@swende.se>

This adds a new client method BlockNumber to fetch the most recent
block number of the chain.

* core/vm/testdata: add gascost expectations to testcases

* core/vm: verify expected gas in tests for precompiles

* core/vm: fix overflow flaw in gas/s calculation

* cmd, eth: offer maxprice flag for overwritting price cap

* eth: rename default price cap

eth/downloader: only roll back light sync if not fully validating

params: update CHTs for v1.9.21 release

* accounts/usbwallet, signer/core: un-hide accounts from ledger legacy derivation paths

* Update accounts/usbwallet/wallet.go

* Update signer/core/api.go

* Update signer/core/api.go

* whisper: remove whisper

* Update cmd/geth/config.go
Co-authored-by: NMarius van der Wijden <m.vanderwijden@live.de>

* cmd/geth: warn on enabling whisper + remove more whisper deps

* mobile: remove all whisper references
Co-authored-by: NMarius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: NMartin Holst Swende <martin@swende.se>

accounts: abi/bid/backends; cleaned doc errors, camelCase refactors and anonymous variable assignments (#21514)
Co-authored-by: NOsoro Bironga <osoro@doctaroo.com>

* eth: Added TraceTransactionPending

* eth: Implement Trace_Call, remove traceTxPending

* eth: debug_call -> debug_traceCall, recompute tx environment if pruned

* eth: fix nil panic

* eth: improve block retrieving logic in tracers

* internal/web3ext: add debug_traceCall to console

core, eth, trie: prepare trie sync for path based operation

This changes how the downloader works, a little bit. Previously, when block sync started,
we immediately started filling up to 8192 blocks. Usually this is fine, blocks are small
in the early numbers. The threshold then is lowered as we measure the size of the blocks
that are filled.

However, if the node is shut down and restarts syncing while we're in a heavy segment,
that might be bad. This PR introduces a more conservative initial threshold of 2K blocks
instead.

* "Downloader queue stats" is now a DEBUG information

I think this info is more a DEBUG related information then an INFO. If it must remains an INFO, maybe it can be slow down to one time every 5 minutes or so.

* Update queue.go

"Downloader queue stats" information is now provided once every minute instead of once every 10 seconds.

* accounts/abi: fix a bug in getTypeSize method

e.g. for "Tuple[2]" type, the element of the array is a tuple type and the size of the tuple may not be 32.

* accounts/abi: add unit test of getTypeSize method

* tests: add testdata of call tracer

* eth/tracers: return revert reason in call_tracer

* eth/tracers: regenerate assets

* eth/tracers: add error message even if no exec occurrs, fixes #21438
Co-authored-by: NMartin Holst Swende <martin@swende.se>

core/state, eth, trie: stabilize memory use, fix memory leak

* go.mod | goleveldb latest update

* go.mod update

* leveldb options

* go.mod: double check
Co-authored-by: NPéter Szilágyi <peterke@gmail.com>