Merge bitcoin-core/gui#563: qt: Remove network detection based on address in BIP21

b7dbc83f23 qt: Remove network detection based on address in BIP21 (laanwj)

Pull request description:

  This is removes some ugly and brittle code that switches the global network to testnet based on a provided address. I think in practice it's very unlikely for testnet BIP21 payment URIs to be used, and if so it's for testing so it's easy enough to manually copy it. Or to specify `-testnet` explicitly.

  There is already no such case for `-regtest` or `-signet`.

  After this change it will only accept addresses for the explicitly selected network. Others will result in a "wrong network" popup.

  There is also a possibility for refactor after this as the initialization order of `PaymentServer::ipcParseCommandLine` isn't important anymore (well, it still has to be before `PaymentServer::ipcSendCommandLine`, maybe even merged with it), but I have not done so here.

ACKs for top commit:
  jonatack:
    ACK  b7dbc83f23
  achow101:
    ACK b7dbc83f23

Tree-SHA512: ebc77c0e5c98f53fe254bcd0f94c9d1c06937b794346e95b14158860d5c607515e71d73b782d2726674dce86d6d4001085d473c6d1bc11c5e6c25ff3fb3cfa22

src/qt/bitcoin.cpp

@@ -587,7 +587,7 @@ int GuiMain(int argc, char* argv[])
         return EXIT_FAILURE;
     }
 #ifdef ENABLE_WALLET
-    // Parse URIs on command line -- this can affect Params()
+    // Parse URIs on command line
     PaymentServer::ipcParseCommandLine(argc, argv);
 #endif
 

src/qt/paymentserver.cpp

@@ -78,32 +78,11 @@ void PaymentServer::ipcParseCommandLine(int argc, char* argv[])
     for (int i = 1; i < argc; i++)
     {
         QString arg(argv[i]);
-        if (arg.startsWith("-"))
-            continue;
+        if (arg.startsWith("-")) continue;
 
-        // If the bitcoin: URI contains a payment request, we are not able to detect the
-        // network as that would require fetching and parsing the payment request.
-        // That means clicking such an URI which contains a testnet payment request
-        // will start a mainnet instance and throw a "wrong network" error.
         if (arg.startsWith(BITCOIN_IPC_PREFIX, Qt::CaseInsensitive)) // bitcoin: URI
         {
-            if (savedPaymentRequests.contains(arg)) continue;
             savedPaymentRequests.insert(arg);
-
-            SendCoinsRecipient r;
-            if (GUIUtil::parseBitcoinURI(arg, &r) && !r.address.isEmpty())
-            {
-                auto tempChainParams = CreateChainParams(gArgs, CBaseChainParams::MAIN);
-
-                if (IsValidDestinationString(r.address.toStdString(), *tempChainParams)) {
-                    SelectParams(CBaseChainParams::MAIN);
-                } else {
-                    tempChainParams = CreateChainParams(gArgs, CBaseChainParams::TESTNET);
-                    if (IsValidDestinationString(r.address.toStdString(), *tempChainParams)) {
-                        SelectParams(CBaseChainParams::TESTNET);
-                    }
-                }
-            }
         }
     }
 }