Merge #17985: net: Remove forcerelay of rejected txs

facb71576cd4d2e90fd03e09d29b42fa3d730e8c net: Remove forcerelay of rejected txs (MarcoFalke)

Pull request description:

  This removes the code that supposedly handled the forced relay of txs from a permissioned peer that were rejected from our mempool. The removal should be fine, because it is dead code for the following reasons:

  * While `RelayTransaction` enqueues the inv for all peers, the inv is never processed because it can not be found in the mempool. See https://github.com/bitcoin/bitcoin/blob/4a072330763b3ff2d1b5c5b8d30a9517873ac6de/src/net_processing.cpp#L3862-L3866

  * Even if the peers we intended to send the inv to can somehow reply with a getdata to the never-received inv, they won't receive the tx as a reply because it was never added to the "relay memory" (`mapRelay`)

  The dead code is (obviously) untested: https://marcofalke.github.io/btc_cov/total.coverage/src/net_processing.cpp.gcov.html#2574

  This feature was (intentionally or accidentally) removed in 4d8993b3469915d8c9ba4cd3b918f16782edf0de, which was released in Bitcoin Core 0.13.0. So all currently supported versions of Bitcoin Core ship without this feature. I am not aware of any complaints about this feature or actual documented use-cases. So instead of reviving an unneeded feature, just remove the dead code.

ACKs for top commit:
  hebasto:
    ACK facb71576cd4d2e90fd03e09d29b42fa3d730e8c, locally running the unit and functional tests.

Tree-SHA512: bfceae6f2983c1510fa0649a9a63c343cbbc1c4ab3a3698039cccf454c81e58c8f5114b147ed42a1bc867da74c43a5b53764ab14f942e191b6f59079044108b5

1 files changed, 2 insertions, 2 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 24a1fd27db..ece6214aa8 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -450,7 +450,7 @@ void SetupServerArgs()
     gArgs.AddArg("-whitebind=<[permissions@]addr>", "Bind to given address and whitelist peers connecting to it. "
         "Use [host]:port notation for IPv6. Allowed permissions are bloomfilter (allow requesting BIP37 filtered blocks and transactions), "
         "noban (do not ban for misbehavior), "
-        "forcerelay (relay even non-standard transactions), "
+        "forcerelay (relay transactions that are already in the mempool; implies relay), "
         "relay (relay even in -blocksonly mode), "
         "and mempool (allow requesting BIP35 mempool contents). "
         "Specify multiple permissions separated by commas (default: noban,mempool,relay). Can be specified multiple times.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
@@ -527,7 +527,7 @@ void SetupServerArgs()
     gArgs.AddArg("-datacarriersize", strprintf("Maximum size of data in data carrier transactions we relay and mine (default: %u)", MAX_OP_RETURN_RELAY), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     gArgs.AddArg("-minrelaytxfee=<amt>", strprintf("Fees (in %s/kB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)",
         CURRENCY_UNIT, FormatMoney(DEFAULT_MIN_RELAY_TX_FEE)), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
-    gArgs.AddArg("-whitelistforcerelay", strprintf("Add 'forcerelay' permission to whitelisted inbound peers with default permissions. This will relay transactions even if the transactions were already in the mempool or violate local relay policy. (default: %d)", DEFAULT_WHITELISTFORCERELAY), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    gArgs.AddArg("-whitelistforcerelay", strprintf("Add 'forcerelay' permission to whitelisted inbound peers with default permissions. This will relay transactions even if the transactions were already in the mempool. (default: %d)", DEFAULT_WHITELISTFORCERELAY), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     gArgs.AddArg("-whitelistrelay", strprintf("Add 'relay' permission to whitelisted inbound peers with default permissions. This will accept relayed transactions even when not relaying transactions (default: %d)", DEFAULT_WHITELISTRELAY), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);