Fix relay mechanism for whitelisted peers under blocks only mode.

Previously in blocks only mode all inv messages where type!=MSG_BLOCK would be
rejected without regard for whitelisting or whitelistalwaysrelay.

As such whitelisted peers would never send the transaction (which would be
processed).

src/main.cpp

@@ -4210,6 +4210,12 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             return error("message inv size() = %u", vInv.size());
         }
 
+        bool fBlocksOnly = GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY);
+
+        // Allow whitelisted peers to send data other than blocks in blocks only mode if whitelistalwaysrelay is true
+        if (pfrom->fWhitelisted && GetBoolArg("-whitelistalwaysrelay", DEFAULT_WHITELISTALWAYSRELAY))
+            fBlocksOnly = false;
+
         LOCK(cs_main);
 
         std::vector<CInv> vToFetch;
@@ -4224,9 +4230,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             bool fAlreadyHave = AlreadyHave(inv);
             LogPrint("net", "got inv: %s  %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom->id);
 
-            if (!fAlreadyHave && !fImporting && !fReindex && inv.type != MSG_BLOCK && !GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY))
-                pfrom->AskFor(inv);
-
             if (inv.type == MSG_BLOCK) {
                 UpdateBlockAvailability(pfrom->GetId(), inv.hash);
                 if (!fAlreadyHave && !fImporting && !fReindex && !mapBlocksInFlight.count(inv.hash)) {
@@ -4250,6 +4253,13 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
                     LogPrint("net", "getheaders (%d) %s to peer=%d\n", pindexBestHeader->nHeight, inv.hash.ToString(), pfrom->id);
                 }
             }
+            else
+            {
+                if (fBlocksOnly)
+                    LogPrint("net", "peer sent inv %s in violation of protocol peer=%d\n", inv.ToString(), pfrom->id);
+                else if (!fAlreadyHave && !fImporting && !fReindex)
+                    pfrom->AskFor(inv);
+            }
 
             // Track requests for our stuff
             GetMainSignals().Inventory(inv.hash);