reset, revert difficulty algorithm, set fork height

README.md

@@ -85,7 +85,7 @@ Dates are provided in the format YYYY-MM-DD.
 | 160,777                          | 2019-11-20 | Gaping Goatse    | v0.7.0.0               | v0.7.1.0                  | Only allow >= 2 outputs, change to the block median used to calculate penalty, rct sigs in coinbase forbidden, 4 unlock time as protocol rule
 | -                         | 2020-06-28 | Hallucinogenic Hypnotoad  | v0.8.0.0               | v0.8.0.2                  | Dandelion++ support
 | 253,999                         | 2020-10-09 | Illiterate Illuminati  | v0.9.0.0               | v0.9.3.3                  | Dynamic coinbase unlock (up to 1 mo.), Deterministic unlock times, Enforce maximum coinbase amount, show_qr_code wallet command, CLSAG
-| 331,519                         | 2021-07-04 | Junkie Jeff  | v0.10.0.0               | v0.10.0.0                  | Bulletproofs+, Miner Block Header Signing, Reduce dynamic coinbase unlock time (2 weeks™), Reset difficulty and switch back to Monero's difficulty algorithm
+| 331,571                         | 2021-07-04 | Junkie Jeff  | v0.10.0.0               | v0.10.0.0                  | Bulletproofs+, Miner Block Header Signing, Reduce dynamic coinbase unlock time (2 weeks™), Reset difficulty and switch back to Monero's difficulty algorithm
 
 X's indicate that these details have not been determined as of commit date.
 

src/cryptonote_basic/difficulty.cpp

@@ -216,6 +216,7 @@ namespace cryptonote {
       return 1;
     }
     if (HEIGHT < 200 && HEIGHT > 2 && m_nettype == TESTNET) { return 500; }
+    if (HEIGHT <= DIFFICULTY_RESET_HEIGHT + DIFFICULTY_WINDOW && HEIGHT >= DIFFICULTY_RESET_HEIGHT && m_nettype == MAINNET) { return DIFFICULTY_RESET_LEVEL; }
     static_assert(DIFFICULTY_WINDOW >= 2, "Window is too small");
     assert(length <= DIFFICULTY_WINDOW);
     sort(timestamps.begin(), timestamps.end());

src/cryptonote_config.h

@@ -87,6 +87,8 @@
 #define DIFFICULTY_BLOCKS_COUNT_V3                      DIFFICULTY_WINDOW_V3 + 1 // added +1 to make N=N
 #define DIFFICULTY_BLOCKS_COUNT_V2                      DIFFICULTY_WINDOW_V2 + 1 // added +1 to make N=N
 #define DIFFICULTY_BLOCKS_COUNT                         DIFFICULTY_WINDOW + DIFFICULTY_LAG
+#define DIFFICULTY_RESET_HEIGHT                         331571 // ~July 4, 2021 Pool Independence Day
+#define DIFFICULTY_RESET_LEVEL                          100000000 // 100 mill
 
 
 #define CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_SECONDS_V1   DIFFICULTY_TARGET_V1 * CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_BLOCKS

src/cryptonote_core/blockchain.cpp

@@ -950,7 +950,7 @@ start:
 
   difficulty_type diff = next_difficulty(timestamps, m_nettype, difficulties, target, HEIGHT);
 
-  if (version >= 11) {
+  if (version <= 17 && version >= 11) {
     diff = next_difficulty_v5(timestamps, m_nettype, difficulties, T, N, HEIGHT);
   } else if (version == 10) {
     diff = next_difficulty_v4(timestamps, m_nettype, difficulties, HEIGHT);
@@ -1045,7 +1045,7 @@ size_t Blockchain::recalculate_difficulties(boost::optional<uint64_t> start_heig
     size_t target = get_ideal_hard_fork_version(height) < 2 ? DIFFICULTY_TARGET_V1 : DIFFICULTY_TARGET_V2;
     difficulty_type recalculated_diff = next_difficulty(timestamps, m_nettype, difficulties, target, HEIGHT);
     
-    if (version >= 11) {
+    if (version <= 17 && version >= 11) {
       recalculated_diff = next_difficulty_v5(timestamps, m_nettype, difficulties, T, N, HEIGHT);
     } else if (version == 10) {
       recalculated_diff = next_difficulty_v4(timestamps, m_nettype, difficulties, HEIGHT);
@@ -1360,7 +1360,7 @@ difficulty_type Blockchain::get_next_difficulty_for_alternative_chain(const std:
   uint64_t HEIGHT = m_db->height();
 
   // calculate the difficulty target for the block and return it
-  if (version >= 11) {
+  if (version <= 17 && version >= 11) {
     return next_difficulty_v5(timestamps, m_nettype, cumulative_difficulties, T, N, HEIGHT);
   } else if (version == 10) {
     return next_difficulty_v4(timestamps, m_nettype, cumulative_difficulties, HEIGHT);

src/hardforks/hardforks.cpp

@@ -43,6 +43,8 @@ const hardfork_t mainnet_hard_forks[] = {
   { 15, 160777, 0, 1573280497 },
   { 16, 253999, 0, 1600576508 },
   { 17, 254287, 0, 1600576524 },
+  { 18, 331571, 0, 1623245591 },
+  { 19, 331859, 0, 1623693101 },
 };
 const size_t num_mainnet_hard_forks = sizeof(mainnet_hard_forks) / sizeof(mainnet_hard_forks[0]);