Further fixes from code review

Author: gwillen

src/init.cpp

@@ -980,22 +980,25 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         fPruneMode = true;
     }
 
+    uint32_t epoch_length = chainparams.GetConsensus().dynamic_epoch_length;
+    if (epoch_length == std::numeric_limits<uint32_t>::max()) {
+        // That's the default value, for non-dynafed chains and some tests. Pick a more sensible default here.
+        epoch_length = 20160;
+    }
+
     if (args.IsArgSet("-trim_headers")) {
         LogPrintf("Configured for header-trimming mode. This will reduce memory usage substantially, but we will be unable to serve as a full P2P peer, and certain header fields may be missing from JSON RPC output.\n");
         fTrimHeaders = true;
         // This calculation is driven by GetValidFedpegScripts in pegins.cpp, which walks the chain
         //   back to current epoch start, and then an additional total_valid_epochs on top of that.
         //   We add one epoch here for the current partial epoch, and then another one for good luck.
-        // NB: If we're non-dynafed, then:
-        //   - total_valid_epochs = 1
-        //   - dynamic_epoch_length = std::numeric_limits<uint32_t>::max()
-        //   So this will work out to an unhelpfully-large number. XXX: Is this a problem?
-        nMustKeepFullHeaders = (chainparams.GetConsensus().total_valid_epochs + 2) * (chainparams.GetConsensus().dynamic_epoch_length);
+
+        nMustKeepFullHeaders = (chainparams.GetConsensus().total_valid_epochs + 2) * epoch_length;
         // This is the number of headers we can have in flight downloading at a time, beyond the
         //   set of blocks we've already validated. Capping this is necessary to keep memory usage
         //   bounded during IBD.
     }
-    nHeaderDownloadBuffer = chainparams.GetConsensus().dynamic_epoch_length * 2;
+    nHeaderDownloadBuffer = epoch_length * 2;
 
     nConnectTimeout = args.GetArg("-timeout", DEFAULT_CONNECT_TIMEOUT);
     if (nConnectTimeout <= 0) {

src/net_processing.cpp

@@ -911,7 +911,7 @@ bool PeerManagerImpl::TipMayBeStale()
 bool PeerManagerImpl::CanDirectFetch()
 {
     if(!m_chainman.ActiveChain().Tip()) {
-        LogPrint(BCLog::NET, "Startup crash avoided\n");
+        LogPrint(BCLog::NET, "Tried to call CanDirectFetch with no currently-active chain.\n");
         return false;
     }
     return m_chainman.ActiveChain().Tip()->GetBlockTime() > GetAdjustedTime() - m_chainparams.GetConsensus().nPowTargetSpacing * 20;

src/txdb.cpp

@@ -339,7 +339,7 @@ bool CBlockTreeDB::WalkBlockIndexGutsForMaxHeight(int* nHeight) {
     return true;
 }
 
-bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex, int trim_below_height)
+bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex, int trimBelowHeight)
 {
     std::unique_ptr<CDBIterator> pcursor(NewIterator());
 
@@ -371,10 +371,10 @@ bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams,
                 pindexNew->nTx            = diskindex.nTx;
 
                 n_total++;
-                if (diskindex.nHeight >= trim_below_height) {
+                if (diskindex.nHeight >= trimBelowHeight) {
                     n_untrimmed++;
-                    pindexNew->proof          = diskindex.proof;
-                    pindexNew->m_dynafed_params       = diskindex.m_dynafed_params;
+                    pindexNew->proof               = diskindex.proof;
+                    pindexNew->m_dynafed_params    = diskindex.m_dynafed_params;
                     pindexNew->m_signblock_witness = diskindex.m_signblock_witness;
 
                     const uint256 block_hash = pindexNew->GetBlockHash();

src/txdb.h

@@ -85,7 +85,7 @@ class CBlockTreeDB : public CDBWrapper
     void ReadReindexing(bool &fReindexing);
     bool WriteFlag(const std::string &name, bool fValue);
     bool ReadFlag(const std::string &name, bool &fValue);
-    bool LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex, int trim_below_height);
+    bool LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex, int trimBelowHeight);
     // ELEMENTS:
     bool WalkBlockIndexGutsForMaxHeight(int* nHeight);
     bool ReadPAKList(std::vector<std::vector<unsigned char> >& offline_list, std::vector<std::vector<unsigned char> >& online_list, bool& reject);