dgb: delegate redistribute PPLNS-window guard onto get_height_and_last SSOT

Rewire refresh_pplns_cache's inline window guard in redistribute.hpp onto
the get_height_and_last_endpoints.hpp SSOT (PR #414):

  depth = std::min(height, real_chain_length())   -> dgb::pplns_window_depth(...)
  if (depth < 1) return;                           -> if (!dgb::pplns_window_active(depth)) return;

Byte-identical: pplns_window_depth is std::min and pplns_window_active is
depth>=1, so !active == depth<1. No reward-distribution value change.

Proof: dgb_redistribute_delegate_ghal_test re-derives the verbatim inline
std::min/(depth<1) directly (non-circular) and asserts the SSOT call
reproduces it across a height matrix straddling negative/0/1/RCL+-1, both
nets. 3/3 green; prod dgb_redistribute_test 8/8 unchanged. FENCED dgb/ only.
Target in CMake + both build.yml allowlist arms.

Author: frstrtr

.github/workflows/build.yml

@@ -84,7 +84,7 @@ jobs:
                     dgb_gentx_coinbase_test dgb_connection_coinbase_test dgb_pplns_payout_split_test nmc_auxpow_merkle_test nmc_template_builder_test nmc_auxpow_wire_test nmc_reconstruct_won_block_test nmc_mempool_name_test nmc_block_broadcast_test dgb_gentx_share_path_test dgb_conn_pplns_producer_test dgb_other_tx_resolver_test \
                     dgb_other_tx_assembler_test dgb_reconstruct_won_block_test dgb_reconstruct_closure_test dgb_gentx_unpack_test dgb_work_source_test dgb_template_builder_test dgb_embedded_coin_node_test dgb_embedded_tx_select_test dgb_template_other_txs_test dgb_coinbase_value_parity_test dgb_submit_classify_test dgb_aux_parent_coinbase_parity_test dgb_template_capture_test dgb_aux_doge_db_commitment_bind_test dgb_aux_doge_dc_proof_test dgb_aux_doge_bind_parsers_test \
                     rpc_request_test softfork_check_test genesis_check_test algo_select_test digishield_walk_test header_chain_test \
-                    dgb_coin_node_seam_test dgb_block_broadcast_test dgb_won_block_dispatch_test dgb_forced_won_share_dualpath_test dgb_scrypt_pow_test dgb_nonce_grinder_test dgb_regrind_block_test dgb_won_block_finalize_test dgb_share_target_genesis_test dgb_pool_msg_wire_test dgb_get_shares_walk_test dgb_download_stops_test dgb_think_p1_walk_bounds_test dgb_think_p1_desired_emit_test dgb_think_p6_desired_cutoff_test dgb_think_p4_head_keys_test dgb_think_p3_best_head_test dgb_g1_oracle_byte_parity_test dgb_think_p2_walk_bounds_test dgb_expected_time_to_block_test dgb_tail_score_endpoints_test dgb_pool_attempts_per_second_test dgb_pool_efficiency_test dgb_think_p5_best_share_punish_test dgb_auto_ratchet_tail_guard_test dgb_binomial_conf_interval_test dgb_get_height_and_last_endpoints_test v37_test \
+                    dgb_coin_node_seam_test dgb_block_broadcast_test dgb_won_block_dispatch_test dgb_forced_won_share_dualpath_test dgb_scrypt_pow_test dgb_nonce_grinder_test dgb_regrind_block_test dgb_won_block_finalize_test dgb_share_target_genesis_test dgb_pool_msg_wire_test dgb_get_shares_walk_test dgb_download_stops_test dgb_think_p1_walk_bounds_test dgb_think_p1_desired_emit_test dgb_think_p6_desired_cutoff_test dgb_think_p4_head_keys_test dgb_think_p3_best_head_test dgb_g1_oracle_byte_parity_test dgb_think_p2_walk_bounds_test dgb_expected_time_to_block_test dgb_tail_score_endpoints_test dgb_pool_attempts_per_second_test dgb_pool_efficiency_test dgb_think_p5_best_share_punish_test dgb_auto_ratchet_tail_guard_test dgb_binomial_conf_interval_test dgb_get_height_and_last_endpoints_test dgb_redistribute_delegate_ghal_test v37_test \
             -j$(nproc)
 
       - name: Run tests
@@ -216,7 +216,7 @@ jobs:
                     dgb_gentx_coinbase_test dgb_connection_coinbase_test dgb_pplns_payout_split_test nmc_auxpow_merkle_test nmc_template_builder_test nmc_auxpow_wire_test nmc_reconstruct_won_block_test nmc_mempool_name_test nmc_block_broadcast_test dgb_gentx_share_path_test dgb_conn_pplns_producer_test dgb_other_tx_resolver_test \
                     dgb_other_tx_assembler_test dgb_reconstruct_won_block_test dgb_reconstruct_closure_test dgb_gentx_unpack_test dgb_work_source_test dgb_template_builder_test dgb_embedded_coin_node_test dgb_embedded_tx_select_test dgb_template_other_txs_test dgb_coinbase_value_parity_test dgb_submit_classify_test dgb_aux_parent_coinbase_parity_test dgb_template_capture_test dgb_aux_doge_db_commitment_bind_test dgb_aux_doge_dc_proof_test dgb_aux_doge_bind_parsers_test \
                     rpc_request_test softfork_check_test genesis_check_test algo_select_test digishield_walk_test header_chain_test \
-                    dgb_coin_node_seam_test dgb_block_broadcast_test dgb_won_block_dispatch_test dgb_forced_won_share_dualpath_test dgb_scrypt_pow_test dgb_nonce_grinder_test dgb_regrind_block_test dgb_won_block_finalize_test dgb_share_target_genesis_test dgb_pool_msg_wire_test dgb_get_shares_walk_test dgb_download_stops_test dgb_think_p1_walk_bounds_test dgb_think_p1_desired_emit_test dgb_think_p6_desired_cutoff_test dgb_think_p4_head_keys_test dgb_think_p3_best_head_test dgb_g1_oracle_byte_parity_test dgb_think_p2_walk_bounds_test dgb_expected_time_to_block_test dgb_tail_score_endpoints_test dgb_pool_attempts_per_second_test dgb_pool_efficiency_test dgb_think_p5_best_share_punish_test dgb_auto_ratchet_tail_guard_test dgb_binomial_conf_interval_test test_coin_broadcaster test_multiaddress_pplns test_pplns_stress dgb_get_height_and_last_endpoints_test \
+                    dgb_coin_node_seam_test dgb_block_broadcast_test dgb_won_block_dispatch_test dgb_forced_won_share_dualpath_test dgb_scrypt_pow_test dgb_nonce_grinder_test dgb_regrind_block_test dgb_won_block_finalize_test dgb_share_target_genesis_test dgb_pool_msg_wire_test dgb_get_shares_walk_test dgb_download_stops_test dgb_think_p1_walk_bounds_test dgb_think_p1_desired_emit_test dgb_think_p6_desired_cutoff_test dgb_think_p4_head_keys_test dgb_think_p3_best_head_test dgb_g1_oracle_byte_parity_test dgb_think_p2_walk_bounds_test dgb_expected_time_to_block_test dgb_tail_score_endpoints_test dgb_pool_attempts_per_second_test dgb_pool_efficiency_test dgb_think_p5_best_share_punish_test dgb_auto_ratchet_tail_guard_test dgb_binomial_conf_interval_test test_coin_broadcaster test_multiaddress_pplns test_pplns_stress dgb_get_height_and_last_endpoints_test dgb_redistribute_delegate_ghal_test \
                     v37_test \
             -j$(nproc)
 

src/impl/dgb/redistribute.hpp

@@ -22,6 +22,7 @@
 #include "config_pool.hpp"
 #include "share_tracker.hpp"
 #include "share_check.hpp"
+#include "coin/get_height_and_last_endpoints.hpp"
 
 #include <core/log.hpp>
 #include <core/target_utils.hpp>
@@ -450,8 +451,8 @@ class Redistributor
             return;
 
         auto [height, last] = tracker.chain.get_height_and_last(best);
-        int32_t depth = std::min(height, static_cast<int32_t>(PoolConfig::real_chain_length()));
-        if (depth < 1)
+        int32_t depth = dgb::pplns_window_depth(height, static_cast<int32_t>(PoolConfig::real_chain_length()));
+        if (!dgb::pplns_window_active(depth))
             return;
 
         struct AccumEntry { std::vector<unsigned char> script; uint160 hash; uint8_t type; uint64_t weight; };

src/impl/dgb/test/CMakeLists.txt

@@ -763,6 +763,18 @@ if (BUILD_TESTING AND GTest_FOUND)
         core
         c2pool_payout c2pool_merged_mining c2pool_hashrate c2pool_storage)
     gtest_add_tests(dgb_get_height_and_last_endpoints_test "" AUTO)
+
+    # dgb_redistribute_delegate_ghal_test: FENCED, additive byte-identity proof
+    # that redistribute.hpp's PPLNS-window guard was rewired onto the SSOT
+    # coin/get_height_and_last_endpoints.hpp with NO value change. Non-circular:
+    # re-derives the inline std::min/(depth<1) directly. MUST also be in the
+    # build.yml --target allowlist (#143 NOT_BUILT trap).
+    add_executable(dgb_redistribute_delegate_ghal_test redistribute_delegate_ghal_test.cpp)
+    target_link_libraries(dgb_redistribute_delegate_ghal_test PRIVATE
+        GTest::gtest_main GTest::gtest
+        core
+        c2pool_payout c2pool_merged_mining c2pool_hashrate c2pool_storage)
+    gtest_add_tests(dgb_redistribute_delegate_ghal_test "" AUTO)
     # dgb_pool_efficiency_test: FENCED, additive KAT pinning the pool
     # EFFICIENCY / REAL-HASHRATE diagnostics arithmetic in pool_efficiency.hpp vs
     # the p2pool main.py status-loop oracle (stale_prop = (orphan+doa)/total;

src/impl/dgb/test/redistribute_delegate_ghal_test.cpp

@@ -0,0 +1,75 @@
+// dgb redistribute -> get_height_and_last SSOT byte-identity DELEGATION KAT.
+//
+// FENCED, additive. Pins the runtime rewire of redistribute.hpp:454-455
+// (refresh_pplns_cache PPLNS-window guard) onto the SSOT free functions in
+// coin/get_height_and_last_endpoints.hpp. The SSOT itself is proven against the
+// p2pool-dgb-scrypt oracle by dgb_get_height_and_last_endpoints_test; this slice
+// proves only that swapping the inline expression for the SSOT call changed
+// NOTHING -- i.e. the rewire is value-identical, no reward-distribution drift.
+//
+// PRE-delegation inline (verbatim, from git history of redistribute.hpp):
+//     int32_t depth = std::min(height, static_cast<int32_t>(real_chain_length()));
+//     if (depth < 1) return;          // early-out: window inactive
+// POST-delegation (current redistribute.hpp:454-455):
+//     int32_t depth = dgb::pplns_window_depth(height, real_chain_length());
+//     if (!dgb::pplns_window_active(depth)) return;
+//
+// NON-CIRCULAR: the "expected" side below recomputes std::min(...)/(depth < 1)
+// directly from the operands -- it does NOT call the SSOT under test. We then
+// assert the SSOT call reproduces that inline result across a height matrix that
+// straddles every boundary (negative, 0, 1, REAL_CHAIN_LENGTH-1/=/+1).
+// MUST appear in BOTH this dir CMakeLists.txt AND the build.yml --target
+// allowlist, or it becomes a #143 NOT_BUILT sentinel.
+
+#include <impl/dgb/coin/get_height_and_last_endpoints.hpp>
+
+#include <gtest/gtest.h>
+#include <algorithm>
+#include <cstdint>
+
+using namespace dgb;
+
+static constexpr int32_t CL_MAIN = 2880;  // REAL_CHAIN_LENGTH mainnet
+static constexpr int32_t CL_TEST = 400;   // REAL_CHAIN_LENGTH testnet
+
+// The verbatim pre-delegation inline expression, re-implemented here so the
+// expectation is independent of the code under test.
+static int32_t inline_depth(int32_t height, int32_t rcl) {
+    return std::min(height, static_cast<int32_t>(rcl));
+}
+static bool inline_early_return(int32_t depth) {
+    return depth < 1;
+}
+
+static void check_one(int32_t height, int32_t rcl) {
+    const int32_t want_depth = inline_depth(height, rcl);
+    const bool    want_ret   = inline_early_return(want_depth);
+
+    const int32_t got_depth = pplns_window_depth(height, rcl);
+    const bool    got_ret   = !pplns_window_active(got_depth);
+
+    EXPECT_EQ(got_depth, want_depth)
+        << "depth diverged at height=" << height << " rcl=" << rcl;
+    EXPECT_EQ(got_ret, want_ret)
+        << "early-return diverged at height=" << height << " rcl=" << rcl;
+}
+
+TEST(DgbRedistributeDelegateGhal, DepthMatchesInlineMainnet) {
+    for (int32_t h : {-5, -1, 0, 1, 2, 10, 1440, CL_MAIN - 1, CL_MAIN, CL_MAIN + 1, 100000})
+        check_one(h, CL_MAIN);
+}
+
+TEST(DgbRedistributeDelegateGhal, DepthMatchesInlineTestnet) {
+    for (int32_t h : {-5, -1, 0, 1, 2, 10, 200, CL_TEST - 1, CL_TEST, CL_TEST + 1, 100000})
+        check_one(h, CL_TEST);
+}
+
+// Boundary spot-checks pinned to absolute values (no SSOT call on the expected
+// side) -- the window is INACTIVE iff clamped depth < 1, ACTIVE from height 1 up.
+TEST(DgbRedistributeDelegateGhal, ActivationBoundaryAbsolute) {
+    EXPECT_TRUE (!pplns_window_active(pplns_window_depth(0, CL_MAIN)));  // depth 0 -> inactive
+    EXPECT_FALSE(!pplns_window_active(pplns_window_depth(1, CL_MAIN)));  // depth 1 -> active
+    EXPECT_FALSE(!pplns_window_active(pplns_window_depth(CL_MAIN, CL_MAIN))); // clamped, active
+    EXPECT_TRUE (!pplns_window_active(pplns_window_depth(-3, CL_MAIN))); // negative -> inactive
+    EXPECT_EQ(pplns_window_depth(CL_MAIN + 50, CL_MAIN), CL_MAIN);       // clamp to RCL
+}