Merge upstream/main into the fork

Brings the nine commits that are actually the latest on our lineage:
isolated testnet parameters and genesis, optional 2 MB large pages for
RandomX, and five README changes. This is what "up to date" means here --
not the 1.2.2x tags, which carry higher version numbers but were cut
2026-07-30, three weeks before the line we ship, and which upstream/main
does not contain.

Three conflicts, all resolved toward upstream's structure while keeping
what this fork knows:

main.cpp -- upstream moved genesis construction into BuildGenesisBlock() so
mainnet and the new testnet can share it. Verified byte-for-byte before
taking it: MAINNET_GENESIS_TIMESTAMP, _TIME (1753315200), _NONCE (3141),
_HASH, _MERKLE, the scriptPubKey, nBits and nVersion all equal what this
tree built inline. The mainnet genesis hash is unchanged and the asserts
still guard it. Kept our warning about never editing those inputs, and kept
our note that 1753315200 is 2025-07-24, not 2026 -- upstream's comment on
that constant states the wrong year.

net.h -- DEFAULT_PORT = htons(8433) becomes MAINNET_PORT/TESTNET_PORT in
host order. Nothing is lost: net.cpp's GetDefaultPort() applies htons()
itself and is what every caller uses, so the value reaching a sockaddr is
unchanged and mainnet stays on 8433.

selftest.cpp -- the known-tests string had diverged in both directions.
Took the union: upstream's network-params alongside our payout-ledger,
rather than dropping either.

Gates: 15/15 selftests (our 14 plus upstream's network-params), consensus
constants unchanged against e4f898c except the pre-existing
MAX_BLOCK_SIZE_GEN, mainnet genesis intact, compactblock's 17 checks still
pass, money-log check ok, GNU_STACK RW.

1 files changed, 84 insertions, 1 deletions

diff --git a/src/selftest.cpp b/src/selftest.cpp
index 65f215b..357d532 100644
--- a/src/selftest.cpp
+++ b/src/selftest.cpp
@@ -3118,6 +3118,87 @@ static int RunNetMessageSelfTest()
     return nFail == 0 ? 0 : 1;
 }
 
+static int RunNetworkParamsSelfTest()
+{
+    fflush(stdout);
+    printf("network-params self-test\n");
+
+    int nFail = 0;
+    std::string strOldDataDir = strSetDataDir;
+    try
+    {
+        SelectChainParams(false);
+        nFail += Check(!IsTestNet(), "starts on mainnet after explicit selection") ? 0 : 1;
+        nFail += Check(ntohs(GetDefaultPort()) == MAINNET_PORT,
+                       "mainnet default P2P port is 8433") ? 0 : 1;
+        CAddress mainAddr("127.0.0.1");
+        nFail += Check(mainAddr.port == htons(MAINNET_PORT),
+                       "mainnet address parsing uses the mainnet default port") ? 0 : 1;
+        CMessageHeader mainHeader("ping", 0);
+        char mainMagic[4];
+        memcpy(mainMagic, mainHeader.pchMessageStart, sizeof(mainMagic));
+        uint256 mainGenesis = hashGenesisBlock;
+        uint256 mainMerkle = hashGenesisMerkleRoot;
+        unsigned int mainNonce = GENESIS_NONCE;
+
+        SelectChainParams(true);
+        nFail += Check(IsTestNet(), "testnet selection is sticky") ? 0 : 1;
+        nFail += Check(ntohs(GetDefaultPort()) == TESTNET_PORT,
+                       "testnet default P2P port is 18433") ? 0 : 1;
+        CAddress testAddr("127.0.0.1");
+        nFail += Check(testAddr.port == htons(TESTNET_PORT),
+                       "testnet address parsing uses the testnet default port") ? 0 : 1;
+        CMessageHeader testHeader("ping", 0);
+        nFail += Check(memcmp(mainMagic, testHeader.pchMessageStart, sizeof(mainMagic)) != 0,
+                       "testnet message magic differs from mainnet") ? 0 : 1;
+        nFail += Check(hashGenesisBlock != mainGenesis &&
+                       hashGenesisMerkleRoot != mainMerkle &&
+                       GENESIS_NONCE != mainNonce,
+                       "testnet genesis constants differ from mainnet") ? 0 : 1;
+        nFail += Check(hashGenesisBlock == uint256("0xa9d11c6d697bcb7aea0653bc088b12dcf9f44e732df205162cf085fd9d9963eb") &&
+                       hashGenesisMerkleRoot == uint256("0x510b293105e3ff85b8d4c3920e357f85d1a86bf199eb4e7d11f04f380030ec5c") &&
+                       GENESIS_NONCE == 3199,
+                       "testnet genesis constants are pinned") ? 0 : 1;
+
+        std::string tmp;
+        if (!MakeTempDir(tmp))
+        {
+            nFail += Check(false, "creates a temporary data directory") ? 0 : 1;
+        }
+        else
+        {
+            strSetDataDir = tmp;
+            SelectChainParams(false);
+            std::string mainDir = GetAppDir();
+            SelectChainParams(true);
+            std::string testDir = GetAppDir();
+            nFail += Check(mainDir == tmp,
+                           "mainnet uses the selected data directory") ? 0 : 1;
+            nFail += Check(testDir == tmp + "/testnet",
+                           "testnet stores data below a testnet subdirectory") ? 0 : 1;
+            RemoveTree(tmp);
+        }
+    }
+    catch (const std::exception& e)
+    {
+        printf("  FAIL exception: %s\n", e.what());
+        nFail++;
+    }
+    catch (...)
+    {
+        printf("  FAIL unknown exception\n");
+        nFail++;
+    }
+
+    strSetDataDir = strOldDataDir;
+    SelectChainParams(false);
+
+    printf("%s (%d failure%s)\n", nFail == 0 ? "ALL TESTS PASSED" : "TESTS FAILED",
+           nFail, nFail == 1 ? "" : "s");
+    fflush(stdout);
+    return nFail == 0 ? 0 : 1;
+}
+
 static CBlock MakeSizedConsensusBlock(size_t nScriptBytes)
 {
     CTransaction tx;
@@ -3716,6 +3797,8 @@ int RunSelfTest(const std::string& name)
         return RunWalletPortabilitySelfTest();
     if (name == "net-message")
         return RunNetMessageSelfTest();
+    if (name == "network-params")
+        return RunNetworkParamsSelfTest();
     if (name == "consensus-limits")
         return RunConsensusLimitsSelfTest();
     if (name == "pool-stratum")
@@ -3730,6 +3813,6 @@ int RunSelfTest(const std::string& name)
         return RunManagedTorSelfTest();
 
     printf("Unknown self-test '%s'\n", name.c_str());
-    printf("Known self-tests: wallet-keypool, wallet-hd, wallet-format, wallet-storage-sanity, db-env-reopen, wallet-sqlite, wallet-sqlite-migration, wallet-crypto, wallet-encrypt, wallet-sqlite-encrypt, wallet-backend-default, wallet-convert, wallet-portability, net-message, consensus-limits, pool-stratum, payout-ledger, parse-money, socks5-proxy, managed-tor\n");
+    printf("Known self-tests: wallet-keypool, wallet-hd, wallet-format, wallet-storage-sanity, db-env-reopen, wallet-sqlite, wallet-sqlite-migration, wallet-crypto, wallet-encrypt, wallet-sqlite-encrypt, wallet-backend-default, wallet-convert, wallet-portability, net-message, network-params, consensus-limits, pool-stratum, payout-ledger, parse-money, socks5-proxy, managed-tor\n");
     return 1;
 }