RPC validateaddress: test pwalletMain for NULL (no-wallet mode)

src/rpcwallet.cpp

@@ -1479,13 +1479,13 @@ Value validateaddress(const Array& params, bool fHelp)
         CTxDestination dest = address.Get();
         string currentAddress = address.ToString();
         ret.push_back(Pair("address", currentAddress));
-        bool fMine = IsMine(*pwalletMain, dest);
+        bool fMine = pwalletMain ? IsMine(*pwalletMain, dest) : false;
         ret.push_back(Pair("ismine", fMine));
         if (fMine) {
             Object detail = boost::apply_visitor(DescribeAddressVisitor(), dest);
             ret.insert(ret.end(), detail.begin(), detail.end());
         }
-        if (pwalletMain->mapAddressBook.count(dest))
+        if (pwalletMain && pwalletMain->mapAddressBook.count(dest))
             ret.push_back(Pair("account", pwalletMain->mapAddressBook[dest].name));
     }
     return ret;