Enforce Taproot script flags whenever WITNESS is set

1 files changed, 9 insertions, 14 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index f21d6cdbf1..f465c96720 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1581,18 +1581,18 @@ static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS] GUARDED_BY(cs_
 
 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const Consensus::Params& consensusparams)
 {
-    unsigned int flags = SCRIPT_VERIFY_NONE;
-
     // BIP16 didn't become active until Apr 1 2012 (on mainnet, and
     // retroactively applied to testnet)
     // However, only one historical block violated the P2SH rules (on both
-    // mainnet and testnet), so for simplicity, always leave P2SH
-    // on except for the one violating block.
-    if (consensusparams.BIP16Exception.IsNull() || // no bip16 exception on this chain
-        *Assert(block_index.phashBlock) != consensusparams.BIP16Exception) // this block isn't the historical exception
-    {
-        // Enforce WITNESS rules whenever P2SH is in effect
-        flags |= SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS;
+    // mainnet and testnet).
+    // Similarly, only one historical block violated the TAPROOT rules on
+    // mainnet.
+    // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two
+    // violating blocks.
+    uint32_t flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT};
+    const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))};
+    if (it != consensusparams.script_flag_exceptions.end()) {
+        flags = it->second;
     }
 
     // Enforce the DERSIG (BIP66) rule
@@ -1610,11 +1610,6 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const Co
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
-    // Enforce Taproot (BIP340-BIP342)
-    if (DeploymentActiveAt(block_index, consensusparams, Consensus::DEPLOYMENT_TAPROOT)) {
-        flags |= SCRIPT_VERIFY_TAPROOT;
-    }
-
     // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit)
     if (DeploymentActiveAt(block_index, consensusparams, Consensus::DEPLOYMENT_SEGWIT)) {
         flags |= SCRIPT_VERIFY_NULLDUMMY;