Merge bitcoin/bitcoin#21934: RPC/blockchain: getblockchaininfo: Include versionbits signalling details during LOCKED_IN

2b19f34 RPC/blockchain: getblockchaininfo: Include versionbits signalling details during LOCKED_IN (Luke Dashjr)

Pull request description:

  While the signal has no effect during `LOCKED_IN`, the bit is still defined and recommended for measuring uptake. Makes sense to expose statistics too.

ACKs for top commit:
  prayank23:
    ACK bitcoin/bitcoin@2b19f34
  Sjors:
    tACK 2b19f34
  theStack:
    Tested ACK 2b19f34
  MarcoFalke:
    review-only ACK 2b19f34

Tree-SHA512: a9bb5adb21992586119cbb5f87e5348eabcab11d5a3bf769b00b69e466589a669846e503f8384fa8927fd77da0c2d64a54f13a7a55a62980046d70f8255ddf47

Author: MarcoFalke

src/rpc/blockchain.cpp

@@ -1377,23 +1377,24 @@ static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue&
     case ThresholdState::ACTIVE: bip9.pushKV("status", "active"); break;
     case ThresholdState::FAILED: bip9.pushKV("status", "failed"); break;
     }
-    if (ThresholdState::STARTED == thresholdState)
-    {
+    const bool has_signal = (ThresholdState::STARTED == thresholdState || ThresholdState::LOCKED_IN == thresholdState);
+    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);
-    if (ThresholdState::STARTED == thresholdState)
-    {
+    if (has_signal) {
         UniValue statsUV(UniValue::VOBJ);
         BIP9Stats statsStruct = g_versionbitscache.Statistics(active_chain_tip, consensusParams, id);
         statsUV.pushKV("period", statsStruct.period);
-        statsUV.pushKV("threshold", statsStruct.threshold);
         statsUV.pushKV("elapsed", statsStruct.elapsed);
         statsUV.pushKV("count", statsStruct.count);
-        statsUV.pushKV("possible", statsStruct.possible);
+        if (ThresholdState::LOCKED_IN != thresholdState) {
+            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);
@@ -1440,18 +1441,18 @@ RPCHelpMan getblockchaininfo()
                                 {RPCResult::Type::OBJ, "bip9", "status of bip9 softforks (only for \"bip9\" type)",
                                 {
                                     {RPCResult::Type::STR, "status", "one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\""},
-                                    {RPCResult::Type::NUM, "bit", "the bit (0-28) in the block version field used to signal this softfork (only for \"started\" status)"},
+                                    {RPCResult::Type::NUM, "bit", "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::OBJ, "statistics", "numeric statistics about BIP9 signalling for a softfork (only for \"started\" status)",
+                                    {RPCResult::Type::OBJ, "statistics", "numeric statistics about signalling for a softfork (only for \"started\" and \"locked_in\" status)",
                                     {
-                                        {RPCResult::Type::NUM, "period", "the length in blocks of the BIP9 signalling period"},
-                                        {RPCResult::Type::NUM, "threshold", "the number of blocks with the version bit set required to activate the feature"},
+                                        {RPCResult::Type::NUM, "period", "the length in blocks of the signalling period"},
+                                        {RPCResult::Type::NUM, "threshold", "the number of blocks with the version bit set required to activate the feature (only for \"started\" status)"},
                                         {RPCResult::Type::NUM, "elapsed", "the number of blocks elapsed since the beginning of the current period"},
                                         {RPCResult::Type::NUM, "count", "the number of blocks with the version bit set in the current period"},
-                                        {RPCResult::Type::BOOL, "possible", "returns false if there are not enough blocks left in this period to pass activation threshold"},
+                                        {RPCResult::Type::BOOL, "possible", "returns false if there are not enough blocks left in this period to pass activation threshold (only for \"started\" status)"},
                                     }},
                                 }},
                                 {RPCResult::Type::NUM, "height", "height of the first block which the rules are or will be enforced (only for \"buried\" type, or \"bip9\" type with \"active\" status)"},