rpc: getdeploymentinfo: change stats to always refer to current period

On a period boundary, getdeploymentinfo (and previously getblockchaininfo)
would report the status and statistics for the next block rather than
the current block. Change this to always report the status/statistics
of the current block, but add status-next to report the status for the
next block.

1 files changed, 37 insertions, 21 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 42993c47f5..dc5c91fe8a 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1412,45 +1412,60 @@ static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue&
     // For BIP9 deployments.
 
     if (!DeploymentEnabled(consensusParams, id)) return;
+    if (active_chain_tip == nullptr) return;
+
+    auto get_state_name = [](const ThresholdState state) -> std::string {
+        switch (state) {
+        case ThresholdState::DEFINED: return "defined";
+        case ThresholdState::STARTED: return "started";
+        case ThresholdState::LOCKED_IN: return "locked_in";
+        case ThresholdState::ACTIVE: return "active";
+        case ThresholdState::FAILED: return "failed";
+        }
+        return "invalid";
+    };
 
     UniValue bip9(UniValue::VOBJ);
-    const ThresholdState thresholdState = g_versionbitscache.State(active_chain_tip, consensusParams, id);
-    switch (thresholdState) {
-    case ThresholdState::DEFINED: bip9.pushKV("status", "defined"); break;
-    case ThresholdState::STARTED: bip9.pushKV("status", "started"); break;
-    case ThresholdState::LOCKED_IN: bip9.pushKV("status", "locked_in"); break;
-    case ThresholdState::ACTIVE: bip9.pushKV("status", "active"); break;
-    case ThresholdState::FAILED: bip9.pushKV("status", "failed"); break;
-    }
-    const bool has_signal = (ThresholdState::STARTED == thresholdState || ThresholdState::LOCKED_IN == thresholdState);
+
+    const ThresholdState next_state = g_versionbitscache.State(active_chain_tip, consensusParams, id);
+    const ThresholdState current_state = g_versionbitscache.State(active_chain_tip->pprev, consensusParams, id);
+
+    const bool has_signal = (ThresholdState::STARTED == current_state || ThresholdState::LOCKED_IN == current_state);
+
+    // BIP9 parameters
     if (has_signal) {
         bip9.pushKV("bit", consensusParams.vDeployments[id].bit);
     }
     bip9.pushKV("start_time", consensusParams.vDeployments[id].nStartTime);
     bip9.pushKV("timeout", consensusParams.vDeployments[id].nTimeout);
-    int64_t since_height = g_versionbitscache.StateSinceHeight(active_chain_tip, consensusParams, id);
-    bip9.pushKV("since", since_height);
+    bip9.pushKV("min_activation_height", consensusParams.vDeployments[id].min_activation_height);
+
+    // BIP9 status
+    bip9.pushKV("status", get_state_name(current_state));
+    bip9.pushKV("since", g_versionbitscache.StateSinceHeight(active_chain_tip->pprev, consensusParams, id));
+    bip9.pushKV("status-next", get_state_name(next_state));
+
+    // BIP9 signalling status, if applicable
     if (has_signal) {
         UniValue statsUV(UniValue::VOBJ);
         BIP9Stats statsStruct = g_versionbitscache.Statistics(active_chain_tip, consensusParams, id);
         statsUV.pushKV("period", statsStruct.period);
         statsUV.pushKV("elapsed", statsStruct.elapsed);
         statsUV.pushKV("count", statsStruct.count);
-        if (ThresholdState::LOCKED_IN != thresholdState) {
+        if (ThresholdState::LOCKED_IN != current_state) {
             statsUV.pushKV("threshold", statsStruct.threshold);
             statsUV.pushKV("possible", statsStruct.possible);
         }
         bip9.pushKV("statistics", statsUV);
     }
-    bip9.pushKV("min_activation_height", consensusParams.vDeployments[id].min_activation_height);
 
     UniValue rv(UniValue::VOBJ);
     rv.pushKV("type", "bip9");
-    rv.pushKV("bip9", bip9);
-    if (ThresholdState::ACTIVE == thresholdState) {
-        rv.pushKV("height", since_height);
+    if (ThresholdState::ACTIVE == next_state) {
+        rv.pushKV("height", g_versionbitscache.StateSinceHeight(active_chain_tip, consensusParams, id));
     }
-    rv.pushKV("active", ThresholdState::ACTIVE == thresholdState);
+    rv.pushKV("active", ThresholdState::ACTIVE == next_state);
+    rv.pushKV("bip9", bip9);
 
     softforks.pushKV(DeploymentName(id), rv);
 }
@@ -1551,14 +1566,17 @@ RPCHelpMan getblockchaininfo()
 namespace {
 const std::vector<RPCResult> RPCHelpForDeployment{
     {RPCResult::Type::STR, "type", "one of \"buried\", \"bip9\""},
+    {RPCResult::Type::NUM, "height", /*optional=*/true, "height of the first block which the rules are or will be enforced (only for \"buried\" type, or \"bip9\" type with \"active\" status)"},
+    {RPCResult::Type::BOOL, "active", "true if the rules are enforced for the mempool and the next block"},
     {RPCResult::Type::OBJ, "bip9", /*optional=*/true, "status of bip9 softforks (only for \"bip9\" type)",
     {
-        {RPCResult::Type::STR, "status", "one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\""},
         {RPCResult::Type::NUM, "bit", /*optional=*/true, "the bit (0-28) in the block version field used to signal this softfork (only for \"started\" and \"locked_in\" status)"},
         {RPCResult::Type::NUM_TIME, "start_time", "the minimum median time past of a block at which the bit gains its meaning"},
         {RPCResult::Type::NUM_TIME, "timeout", "the median time past of a block at which the deployment is considered failed if not yet locked in"},
-        {RPCResult::Type::NUM, "since", "height of the first block to which the status applies"},
         {RPCResult::Type::NUM, "min_activation_height", "minimum height of blocks for which the rules may be enforced"},
+        {RPCResult::Type::STR, "status", "bip9 status of specified block (one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\")"},
+        {RPCResult::Type::NUM, "since", "height of the first block to which the status applies"},
+        {RPCResult::Type::STR, "status-next", "bip9 status of next block"},
         {RPCResult::Type::OBJ, "statistics", /*optional=*/true, "numeric statistics about signalling for a softfork (only for \"started\" and \"locked_in\" status)",
         {
             {RPCResult::Type::NUM, "period", "the length in blocks of the signalling period"},
@@ -1568,8 +1586,6 @@ const std::vector<RPCResult> RPCHelpForDeployment{
             {RPCResult::Type::BOOL, "possible", /*optional=*/true, "returns false if there are not enough blocks left in this period to pass activation threshold (only for \"started\" status)"},
         }},
     }},
-    {RPCResult::Type::NUM, "height", /*optional=*/true, "height of the first block which the rules are or will be enforced (only for \"buried\" type, or \"bip9\" type with \"active\" status)"},
-    {RPCResult::Type::BOOL, "active", "true if the rules are enforced for the mempool and the next block"},
 };
 
 UniValue DeploymentInfo(const CBlockIndex* tip, const Consensus::Params& consensusParams)