MWEB: UI: Don't allow sending to MWEB addresses until after activation.

src/interfaces/node.cpp

@@ -196,6 +196,7 @@ public:
         return GuessVerificationProgress(Params().TxData(), tip);
     }
     bool isInitialBlockDownload() override { return ::ChainstateActive().IsInitialBlockDownload(); }
+    bool isMWEBActive() override { return ::ChainstateActive().IsMWEBActive(); }
     bool getReindex() override { return ::fReindex; }
     bool getImporting() override { return ::fImporting; }
     void setNetworkActive(bool active) override

src/interfaces/node.h

@@ -139,6 +139,9 @@ public:
     //! Is initial block download.
     virtual bool isInitialBlockDownload() = 0;
 
+    //! Is MWEB activated.
+    virtual bool isMWEBActive() = 0;
+
     //! Get reindex.
     virtual bool getReindex() = 0;
 

src/qt/guiutil.cpp

@@ -212,6 +212,16 @@ bool isDust(interfaces::Node& node, const QString& address, const CAmount& amoun
     return IsDust(txOut, node.getDustRelayFee());
 }
 
+bool isMWEBAddressBeforeActivated(interfaces::Node& node, const QString& address)
+{
+    CTxDestination dest = DecodeDestination(address.toStdString());
+    if (dest.type() == typeid(StealthAddress)) {
+        return !node.isMWEBActive();
+    }
+
+    return false;
+}
+
 QString HtmlEscape(const QString& str, bool fMultiLine)
 {
     QString escaped = str.toHtmlEscaped();

src/qt/guiutil.h

@@ -61,6 +61,9 @@ namespace GUIUtil
     // Returns true if given address+amount meets "dust" definition
     bool isDust(interfaces::Node& node, const QString& address, const CAmount& amount);
 
+    // Returns true if address is of type StealthAddress and MWEB has not yet been activated.
+    bool isMWEBAddressBeforeActivated(interfaces::Node& node, const QString& address);
+
     // HTML escaping for rich text controls
     QString HtmlEscape(const QString& str, bool fMultiLine=false);
     QString HtmlEscape(const std::string& str, bool fMultiLine=false);

src/qt/sendcoinsdialog.cpp

@@ -175,6 +175,10 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         connect(_model->getOptionsModel(), &OptionsModel::mwebFeaturesChanged, this, &SendCoinsDialog::mwebFeatureChanged);
         ui->frameMWEBFeatures->setVisible(_model->getOptionsModel()->getMWEBFeatures());
 
+        bool mweb_active = model->node().isMWEBActive();
+        ui->pushButtonMWEBPegIn->setEnabled(mweb_active);
+        ui->pushButtonMWEBPegIn->setToolTip(mweb_active ? "" : "Pegin is not available until MWEB activation");
+
         // fee section
         for (const int n : confTargets) {
             ui->confTargetSelector->addItem(tr("%1 (%2 blocks)").arg(GUIUtil::formatNiceTimeOffset(n*Params().GetConsensus().nPowTargetSpacing)).arg(n));

src/qt/sendcoinsentry.cpp

@@ -167,6 +167,17 @@ bool SendCoinsEntry::validate(interfaces::Node& node)
         retval = false;
     }
 
+    if (retval && GUIUtil::isMWEBAddressBeforeActivated(node, ui->payTo->text())) {
+        ui->payTo->setValid(false);
+        retval = false;
+
+        QMessageBox msgBox;
+        msgBox.setInformativeText("You cannot send to an MWEB address until after the feature has been activated.");
+        msgBox.setStandardButtons(QMessageBox::Ok);
+        msgBox.setDefaultButton(QMessageBox::Ok);
+        msgBox.exec();
+    }
+
     return retval;
 }
 

src/validation.cpp

@@ -1353,6 +1353,11 @@ bool CChainState::IsInitialBlockDownload() const
     return false;
 }
 
+bool CChainState::IsMWEBActive() const
+{
+    return m_chain.Tip() != nullptr && IsMWEBEnabled(m_chain.Tip(), Params().GetConsensus());
+}
+
 static CBlockIndex *pindexBestForkTip = nullptr, *pindexBestForkBase = nullptr;
 
 static void AlertNotify(const std::string& strMessage)

src/validation.h

@@ -695,6 +695,9 @@ public:
     /** Check whether we are doing an initial block download (synchronizing from disk or network) */
     bool IsInitialBlockDownload() const;
 
+    /** Check whether MWEB has been activated */
+    bool IsMWEBActive() const;
+
     /**
      * Make various assertions about the state of the block index.
      *