[validation] Remove unused first_invalid parameter from ProcessNewBlockHeaders()

No callers use the returned value in first_invalid. Remove it from the
function signature and don't set it in the function.

Author: jnewbery

src/net_processing.cpp

@@ -1698,8 +1698,7 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
     }
 
     BlockValidationState state;
-    CBlockHeader first_invalid_header;
-    if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header)) {
+    if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
         if (state.IsInvalid()) {
             MaybePunishNodeForBlock(pfrom->GetId(), state, via_compact_block, "invalid header received");
             return false;

src/rpc/mining.cpp

@@ -773,7 +773,7 @@ static UniValue submitheader(const JSONRPCRequest& request)
     }
 
     BlockValidationState state;
-    ProcessNewBlockHeaders({h}, state, Params(), /* ppindex */ nullptr, /* first_invalid */ nullptr);
+    ProcessNewBlockHeaders({h}, state, Params());
     if (state.IsValid()) return NullUniValue;
     if (state.IsError()) {
         throw JSONRPCError(RPC_VERIFY_ERROR, FormatStateMessage(state));

src/test/blockfilter_index_tests.cpp

@@ -103,7 +103,7 @@ static bool BuildChain(const CBlockIndex* pindex, const CScript& coinbase_script
         CBlockHeader header = block->GetBlockHeader();
 
         BlockValidationState state;
-        if (!ProcessNewBlockHeaders({header}, state, Params(), &pindex, nullptr)) {
+        if (!ProcessNewBlockHeaders({header}, state, Params(), &pindex)) {
             return false;
         }
     }

src/validation.cpp

@@ -3619,9 +3619,8 @@ bool BlockManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationS
 }
 
 // Exposed wrapper for AcceptBlockHeader
-bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex, CBlockHeader *first_invalid)
+bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex)
 {
-    if (first_invalid != nullptr) first_invalid->SetNull();
     {
         LOCK(cs_main);
         for (const CBlockHeader& header : headers) {
@@ -3630,7 +3629,6 @@ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, BlockValid
             ::ChainstateActive().CheckBlockIndex(chainparams.GetConsensus());
 
             if (!accepted) {
-                if (first_invalid) *first_invalid = header;
                 return false;
             }
             if (ppindex) {

src/validation.h

@@ -222,9 +222,8 @@ bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<cons
  * @param[out] state This may be set to an Error state if any error occurred processing them
  * @param[in]  chainparams The params for the chain we want to connect to
  * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers
- * @param[out] first_invalid First header that fails validation, if one exists
  */
-bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr, CBlockHeader* first_invalid = nullptr) LOCKS_EXCLUDED(cs_main);
+bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr) LOCKS_EXCLUDED(cs_main);
 
 /** Open a block file (blk?????.dat) */
 FILE* OpenBlockFile(const FlatFilePos &pos, bool fReadOnly = false);