Update -blocksonly documentation

Summary:
> When -blocksonly is set to 1, it interacts with the -walletbroadcast
> parameter and sets it to 0 if it has not been set already.This behavior
> is not captured by the current documentation, which claims that -blocksonly
> does not impact any wallet transactions.
>
> Update the max number of outgoing peers from 8 to 10, due to the
> addition of two -blocksonly peers.

This is a backport of Core [[bitcoin/bitcoin#18391 | PR18391]] and [[bitcoin/bitcoin#18464 | PR18464]]

Test Plan: `ninja && src/bitcoind -help`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D8894

doc/reduce-memory.md

@@ -24,8 +24,9 @@ The size of some in-memory caches can be reduced. As caches trade off memory usa
 
 ## Number of peers
 
-- `-maxconnections=<n>` - the maximum number of connections, this defaults to `125`. Each active connection takes up some memory. Only significant if incoming
-   connections are enabled, otherwise the number of connections will never be more than `8`.
+- `-maxconnections=<n>` - the maximum number of connections, this defaults to 4096. Each active connection takes up some
+  memory. This option applies only if incoming connections are enabled, otherwise the number of connections will never
+  be more than 10. Of the 10 outbound peers, there can be 8 full-relay connections and 2 block-relay-only ones.
 
 ## Thread configuration
 

doc/reduce-traffic.md

@@ -3,8 +3,10 @@ Reduce Traffic
 
 Some node operators need to deal with bandwidth caps imposed by their ISPs.
 
-By default, Bitcoin ABC allows up to 125 connections to different peers, 8 of
-which are outbound. You can therefore, have at most 117 inbound connections.
+By default, Bitcoin ABC allows up to 4096 connections to different peers, 10 of
+which are outbound. You can therefore, have at most 4086 inbound connections.
+Of the 10 outbound peers, there can be 8 full-relay connections and 2
+block-relay-only ones.
 
 The default settings can result in relatively significant traffic consumption.
 
@@ -26,7 +28,7 @@ calculating the target.
 
 ## 2. Disable "listening" (`-listen=0`)
 
-Disabling listening will result in fewer nodes connected (remember the maximum of 8
+Disabling listening will result in fewer nodes connected (remember the maximum of 10
 outbound peers). Fewer nodes will result in less traffic usage as you are relaying
 blocks and transactions to fewer nodes.
 
@@ -44,7 +46,11 @@ with other peers, you can disable transaction relay.
 Be reminded of the effects of this setting.
 
 - Fee estimation will no longer work.
-- Not relaying other's transactions could hurt your privacy if used while a
-  wallet is loaded or if you use the node to broadcast transactions.
+- It sets the flag "-walletbroadcast" to be "0", only if it is currently unset.
+  Doing so disables the automatic broadcasting of transactions from wallet. Not
+  relaying other's transactions could hurt your privacy if used while a wallet
+  is loaded or if you use the node to broadcast transactions.
+- If a peer is whitelisted and "-whitelistforcerelay" is set to "1" (which will
+  also set "whitelistrelay" to "1"), we will still receive and relay their transactions.
 - It makes block propagation slower because compact block relay can only be
   used when transaction relay is enabled.

src/init.cpp

@@ -446,11 +446,13 @@ void SetupServerArgs(NodeContext &node) {
                    ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg(
         "-blocksonly",
-        strprintf(
-            "Whether to reject transactions from network peers. Transactions "
-            "from the wallet, RPC and relay whitelisted inbound peers RPC are"
-            " not affected. (default: %u)",
-            DEFAULT_BLOCKSONLY),
+        strprintf("Whether to reject transactions from network peers.  "
+                  "Automatic broadcast and rebroadcast of any transactions "
+                  "from inbound peers is disabled, unless "
+                  "'-whitelistforcerelay' is '1', in which case whitelisted "
+                  "peers' transactions will be relayed. RPC transactions are"
+                  " not affected. (default: %u)",
+                  DEFAULT_BLOCKSONLY),
         ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg(
         "-conf=<file>",