'sendrawtransaction' improvements

- Make it report the reject code and reason
- Make it possible to re-send transactions that are already in the mempool

src/rpcprotocol.h

@@ -49,6 +49,9 @@ enum RPCErrorCode
     RPC_INVALID_PARAMETER           = -8,  // Invalid, missing or duplicate parameter
     RPC_DATABASE_ERROR              = -20, // Database error
     RPC_DESERIALIZATION_ERROR       = -22, // Error parsing or validating structure in raw format
+    RPC_TRANSACTION_ERROR           = -25, // General error during transaction submission
+    RPC_TRANSACTION_REJECTED        = -26, // Transaction was rejected by network rules
+    RPC_TRANSACTION_ALREADY_IN_CHAIN= -27, // Transaction already in chain
 
     // P2P client errors
     RPC_CLIENT_NOT_CONNECTED        = -9,  // Bitcoin is not connected

src/rpcrawtransaction.cpp

@@ -777,25 +777,23 @@ Value sendrawtransaction(const Array& params, bool fHelp)
     }
     uint256 hashTx = tx.GetHash();
 
-    bool fHave = false;
     CCoinsViewCache &view = *pcoinsTip;
     CCoins existingCoins;
-    {
-        fHave = view.GetCoins(hashTx, existingCoins);
-        if (!fHave) {
-            // push to local node
-            CValidationState state;
-            if (!AcceptToMemoryPool(mempool, state, tx, false, NULL, !fOverrideFees))
-                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX rejected"); // TODO: report validation state
+    bool fHaveMempool = mempool.exists(hashTx);
+    bool fHaveChain = view.GetCoins(hashTx, existingCoins) && existingCoins.nHeight < 1000000000;
+    if (!fHaveMempool && !fHaveChain) {
+        // push to local node and sync with wallets
+        CValidationState state;
+        if (AcceptToMemoryPool(mempool, state, tx, false, NULL, !fOverrideFees))
+            SyncWithWallets(hashTx, tx, NULL);
+        else {
+            if(state.IsInvalid())
+                throw JSONRPCError(RPC_TRANSACTION_REJECTED, strprintf("%i: %s", state.GetRejectCode(), state.GetRejectReason()));
+            else
+                throw JSONRPCError(RPC_TRANSACTION_ERROR, state.GetRejectReason());
         }
-    }
-    if (fHave) {
-        if (existingCoins.nHeight < 1000000000)
-            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "transaction already in block chain");
-        // Not in block, but already in the memory pool; will drop
-        // through to re-relay it.
-    } else {
-        SyncWithWallets(hashTx, tx, NULL);
+    } else if (fHaveChain) {
+        throw JSONRPCError(RPC_TRANSACTION_ALREADY_IN_CHAIN, "transaction already in block chain");
     }
     RelayTransaction(tx, hashTx);