Merge #15063: GUI: If BIP70 is disabled, attempt to fall back to BIP21 parsing

84f53154e Travis: Add test without BIP70 (but still full wallet + tests) (Luke Dashjr)
113f0004b GUI: If BIP70 is disabled, give a proper error when trying to open a payment request file (Luke Dashjr)
9975282fa GUI: If BIP70 is disabled, attempt to fall back to BIP21 parsing (Luke Dashjr)

Pull request description:

Tree-SHA512: 66a684ce4336d0eac8b0107b405ff3a2cf312258a967f3e1b14734cd39db11e2db3e9b03492755583170d94d54754ef536b0776e5f19a0cc2caca8379eeb4495

.travis.yml

@@ -132,6 +132,15 @@ jobs:
         GOAL="install"
         BITCOIN_CONFIG="--enable-zmq --with-incompatible-bdb --with-gui=qt5 CPPFLAGS=-DDEBUG_LOCKORDER --with-sanitizers=address,integer,undefined CC=clang CXX=clang++"
 
+    - stage: test
+      name: 'x86_64 Linux  [GOAL: install]  [no BIP70]'
+      env: >-
+        HOST=x86_64-unknown-linux-gnu
+        PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libssl1.0-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
+        NO_DEPENDS=1
+        GOAL="install"
+        BITCOIN_CONFIG="--enable-zmq --disable-bip70 --with-incompatible-bdb --with-gui=qt5 CPPFLAGS=-DDEBUG_LOCKORDER --with-sanitizers=address,integer,undefined CC=clang CXX=clang++"
+
     - stage: test
       name: 'x86_64 Linux  [GOAL: install]  [bionic]  [no wallet]'
       env: >-

src/qt/paymentserver.cpp

@@ -292,9 +292,9 @@ void PaymentServer::handleURIOrFile(const QString& s)
     else if (s.startsWith(BITCOIN_IPC_PREFIX, Qt::CaseInsensitive)) // bitcoin: URI
     {
         QUrlQuery uri((QUrl(s)));
+#ifdef ENABLE_BIP70
         if (uri.hasQueryItem("r")) // payment request URI
         {
-#ifdef ENABLE_BIP70
             Q_EMIT message(tr("URI handling"),
                 tr("You are using a BIP70 URL which will be unsupported in the future."),
                 CClientUIInterface::ICON_WARNING);
@@ -315,19 +315,23 @@ void PaymentServer::handleURIOrFile(const QString& s)
                     tr("Payment request fetch URL is invalid: %1").arg(fetchUrl.toString()),
                     CClientUIInterface::ICON_WARNING);
             }
-#else
-            Q_EMIT message(tr("URI handling"),
-                tr("Cannot process payment request because BIP70 support was not compiled in."),
-                CClientUIInterface::ICON_WARNING);
-#endif
             return;
         }
-        else // normal URI
+        else
+#endif
+        // normal URI
         {
             SendCoinsRecipient recipient;
             if (GUIUtil::parseBitcoinURI(s, &recipient))
             {
                 if (!IsValidDestinationString(recipient.address.toStdString())) {
+#ifndef ENABLE_BIP70
+                    if (uri.hasQueryItem("r")) {  // payment request
+                        Q_EMIT message(tr("URI handling"),
+                            tr("Cannot process payment request because BIP70 support was not compiled in."),
+                            CClientUIInterface::ICON_WARNING);
+                    }
+#endif
                     Q_EMIT message(tr("URI handling"), tr("Invalid payment address %1").arg(recipient.address),
                         CClientUIInterface::MSG_ERROR);
                 }
@@ -343,9 +347,9 @@ void PaymentServer::handleURIOrFile(const QString& s)
         }
     }
 
-#ifdef ENABLE_BIP70
     if (QFile::exists(s)) // payment request file
     {
+#ifdef ENABLE_BIP70
         PaymentRequestPlus request;
         SendCoinsRecipient recipient;
         if (!readPaymentRequestFromFile(s, request))
@@ -358,8 +362,12 @@ void PaymentServer::handleURIOrFile(const QString& s)
             Q_EMIT receivedPaymentRequest(recipient);
 
         return;
-    }
+#else
+        Q_EMIT message(tr("Payment request file handling"),
+            tr("Cannot process payment request because BIP70 support was not compiled in."),
+            CClientUIInterface::ICON_WARNING);
 #endif
+    }
 }
 
 void PaymentServer::handleURIConnection()