From c28c5ce619451c75ccbeebf855e699f5d8e4a3f5 Mon Sep 17 00:00:00 2001
From: Pablo Greco <psgreco@gmail.com>
Date: Fri, 29 Sep 2023 12:04:59 -0700
Subject: [PATCH] Allow untrimming headers when needed

---
 src/chain.cpp      | 14 ++++++++++++++
 src/dynafed.cpp    |  4 ++++
 src/pegins.cpp     |  3 +++
 src/validation.cpp | 18 ++++++++++++++++++
 src/validation.h   |  1 +
 5 files changed, 40 insertions(+)

diff --git a/src/chain.cpp b/src/chain.cpp
index fc36659025..e66d1edbe0 100644
--- a/src/chain.cpp
+++ b/src/chain.cpp
@@ -56,6 +56,20 @@ CBlockLocator CChain::GetLocator(const CBlockIndex *pindex) const {
     return CBlockLocator(vHave);
 }
 
+void CBlockIndex::untrim() {
+    if (!trimmed())
+        return;
+    CBlockIndex tmp;
+    const CBlockIndex *pindexfull = untrim_to(&tmp);
+    assert(pindexfull!=this);
+    m_trimmed = false;
+    set_stored();
+    proof = pindexfull->proof;
+    m_dynafed_params = pindexfull->m_dynafed_params;
+    m_signblock_witness = pindexfull->m_signblock_witness;
+    m_pcontext->chainman->m_blockman.m_dirty_blockindex.insert(this);
+}
+
 const CBlockIndex *CBlockIndex::untrim_to(CBlockIndex *pindexNew) const
 {
     return m_pcontext->chainman->m_blockman.m_block_tree_db->RegenerateFullIndex(this, pindexNew);
diff --git a/src/dynafed.cpp b/src/dynafed.cpp
index 8ef680e296..29a2029483 100644
--- a/src/dynafed.cpp
+++ b/src/dynafed.cpp
@@ -1,6 +1,7 @@
 
 #include <dynafed.h>
 #include <hash.h>
+#include <validation.h>
 
 bool NextBlockIsParameterTransition(const CBlockIndex* pindexPrev, const Consensus::Params& consensus, DynaFedParamEntry& winning_entry)
 {
@@ -15,6 +16,7 @@ bool NextBlockIsParameterTransition(const CBlockIndex* pindexPrev, const Consens
     for (int32_t height = next_height - 1; height >= (int32_t)(next_height - consensus.dynamic_epoch_length); --height) {
         const CBlockIndex* p_epoch_walk = pindexPrev->GetAncestor(height);
         assert(p_epoch_walk);
+        ForceUntrimHeader(p_epoch_walk);
         const DynaFedParamEntry& proposal = p_epoch_walk->dynafed_params().m_proposed;
         const uint256 proposal_root = proposal.CalculateRoot();
         vote_tally[proposal_root]++;
@@ -60,6 +62,7 @@ DynaFedParamEntry ComputeNextBlockFullCurrentParameters(const CBlockIndex* pinde
     // may be pre-dynafed params
     const CBlockIndex* p_epoch_start = pindexPrev->GetAncestor(epoch_start_height);
     assert(p_epoch_start);
+    ForceUntrimHeader(p_epoch_start);
     if (p_epoch_start->dynafed_params().IsNull()) {
         // We need to construct the "full" current parameters of pre-dynafed
         // consensus
@@ -93,6 +96,7 @@ DynaFedParamEntry ComputeNextBlockCurrentParameters(const CBlockIndex* pindexPre
 {
     assert(pindexPrev);
 
+    ForceUntrimHeader(pindexPrev);
     DynaFedParamEntry entry = ComputeNextBlockFullCurrentParameters(pindexPrev, consensus);
 
     uint32_t next_height = pindexPrev->nHeight+1;
diff --git a/src/pegins.cpp b/src/pegins.cpp
index 370ffcb83b..60e3b3f4b1 100644
--- a/src/pegins.cpp
+++ b/src/pegins.cpp
@@ -26,6 +26,8 @@
 // ELEMENTS
 //
 
+#include <validation.h>
+
 namespace {
 static secp256k1_context* secp256k1_ctx_validation;
 
@@ -487,6 +489,7 @@ std::vector<std::pair<CScript, CScript>> GetValidFedpegScripts(const CBlockIndex
             break;
         }
 
+        ForceUntrimHeader(p_epoch_start);
         if (!p_epoch_start->dynafed_params().IsNull()) {
             fedpegscripts.push_back(std::make_pair(p_epoch_start->dynafed_params().m_current.m_fedpeg_program, p_epoch_start->dynafed_params().m_current.m_fedpegscript));
         } else {
diff --git a/src/validation.cpp b/src/validation.cpp
index 1cb4abf75b..a6bcfb19db 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2573,6 +2573,11 @@ bool CChainState::FlushStateToDisk(
             {
                 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH);
 
+                if (node::fTrimHeaders) {
+                    for (std::set<CBlockIndex*>::iterator it = setTrimmableBlockIndex.begin(); it != setTrimmableBlockIndex.end(); it++) {
+                        (*it)->untrim();
+                    }
+                }
                 if (!m_blockman.WriteBlockIndexDB()) {
                     return AbortNode(state, "Failed to write to block index database");
                 }
@@ -2709,6 +2714,17 @@ static void UpdateTipLog(
         !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : "");
 }
 
+void ForceUntrimHeader(const CBlockIndex *pindex_)
+{
+    assert(pindex_);
+    if (!pindex_->trimmed()) {
+        return;
+    }
+    AssertLockHeld(cs_main);
+    CBlockIndex *pindex=const_cast<CBlockIndex*>(pindex_);
+    pindex->untrim();
+}
+
 void CChainState::UpdateTip(const CBlockIndex* pindexNew)
 {
     AssertLockHeld(::cs_main);
@@ -2754,11 +2770,13 @@ void CChainState::UpdateTip(const CBlockIndex* pindexNew)
     }
     UpdateTipLog(coins_tip, pindexNew, m_params, __func__, "", warning_messages.original);
 
+    ForceUntrimHeader(pindexNew);
     // Do some logging if dynafed parameters changed.
     if (pindexNew->pprev && !pindexNew->dynafed_params().IsNull()) {
         int height = pindexNew->nHeight;
         uint256 hash = pindexNew->GetBlockHash();
         uint256 root = pindexNew->dynafed_params().m_current.CalculateRoot();
+        ForceUntrimHeader(pindexNew->pprev);
         if (pindexNew->pprev->dynafed_params().IsNull()) {
             LogPrintf("Dynafed activated in block %d:%s: %s\n", height, hash.GetHex(), root.GetHex());
         } else if (root != pindexNew->pprev->dynafed_params().m_current.CalculateRoot()) {
diff --git a/src/validation.h b/src/validation.h
index a27f927fea..78fa8bea6a 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1023,4 +1023,5 @@ bool LoadMempool(CTxMemPool& pool, CChainState& active_chainstate, FopenFn mocka
  */
 const AssumeutxoData* ExpectedAssumeutxo(const int height, const CChainParams& params);
 
+void ForceUntrimHeader(const CBlockIndex *pindex_);
 #endif // BITCOIN_VALIDATION_H