qt: Fix sign message address book filtering

src/qt/addressbookpage.cpp

@@ -20,11 +20,13 @@
 class AddressBookSortFilterProxyModel final : public QSortFilterProxyModel
 {
     const QString m_type;
+    const AddressBookPage::AddressFilter m_address_filter;
 
 public:
-    AddressBookSortFilterProxyModel(const QString& type, QObject* parent)
+    AddressBookSortFilterProxyModel(const QString& type, AddressBookPage::AddressFilter address_filter, QObject* parent)
         : QSortFilterProxyModel(parent)
         , m_type(type)
+        , m_address_filter(address_filter)
     {
         setDynamicSortFilter(true);
         setFilterCaseSensitivity(Qt::CaseInsensitive);
@@ -42,18 +44,23 @@ class AddressBookSortFilterProxyModel final : public QSortFilterProxyModel
         }
 
         auto address = model->index(row, AddressTableModel::Address, parent);
+        if (m_address_filter == AddressBookPage::AddressFilter::Signable &&
+            !model->data(address, AddressTableModel::CanSignMessageRole).toBool()) {
+            return false;
+        }
 
         const auto pattern = filterRegularExpression();
         return (model->data(address).toString().contains(pattern) ||
                 model->data(label).toString().contains(pattern));
     }
 };
 
-AddressBookPage::AddressBookPage(const PlatformStyle *platformStyle, Mode _mode, Tabs _tab, QWidget *parent) :
+AddressBookPage::AddressBookPage(const PlatformStyle *platformStyle, Mode _mode, Tabs _tab, QWidget *parent, AddressFilter _address_filter) :
     QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::AddressBookPage),
     mode(_mode),
-    tab(_tab)
+    tab(_tab),
+    address_filter(_address_filter)
 {
     ui->setupUi(this);
 
@@ -73,7 +80,11 @@ AddressBookPage::AddressBookPage(const PlatformStyle *platformStyle, Mode _mode,
         switch(tab)
         {
         case SendingTab: setWindowTitle(tr("Choose the address to send coins to")); break;
-        case ReceivingTab: setWindowTitle(tr("Choose the address to receive coins with")); break;
+        case ReceivingTab:
+            setWindowTitle(address_filter == AddressFilter::Signable ?
+                tr("Choose the address to sign with") :
+                tr("Choose the address to receive coins with"));
+            break;
         }
         connect(ui->tableView, &QTableView::doubleClicked, this, &QDialog::accept);
         ui->tableView->setEditTriggers(QAbstractItemView::NoEditTriggers);
@@ -89,7 +100,9 @@ AddressBookPage::AddressBookPage(const PlatformStyle *platformStyle, Mode _mode,
         ui->newAddress->setVisible(true);
         break;
     case ReceivingTab:
-        ui->labelExplanation->setText(tr("These are your Bitcoin addresses for receiving payments. Use the 'Create new receiving address' button in the receive tab to create new addresses.\nSigning is only possible with addresses of the type 'legacy'."));
+        ui->labelExplanation->setText(address_filter == AddressFilter::Signable ?
+            tr("These are your Bitcoin addresses that can be used for message signing.") :
+            tr("These are your Bitcoin addresses for receiving payments. Use the 'Create new receiving address' button in the receive tab to create new addresses."));
         ui->deleteAddress->setVisible(false);
         ui->newAddress->setVisible(false);
         break;
@@ -123,7 +136,7 @@ void AddressBookPage::setModel(AddressTableModel *_model)
         return;
 
     auto type = tab == ReceivingTab ? AddressTableModel::Receive : AddressTableModel::Send;
-    proxyModel = new AddressBookSortFilterProxyModel(type, this);
+    proxyModel = new AddressBookSortFilterProxyModel(type, address_filter, this);
     proxyModel->setSourceModel(_model);
 
     connect(ui->searchLineEdit, &QLineEdit::textChanged, proxyModel, &QSortFilterProxyModel::setFilterWildcard);

src/qt/addressbookpage.h

@@ -38,7 +38,12 @@ class AddressBookPage : public QDialog
         ForEditing  /**< Open address book for editing */
     };
 
-    explicit AddressBookPage(const PlatformStyle *platformStyle, Mode mode, Tabs tab, QWidget *parent = nullptr);
+    enum class AddressFilter {
+        ShowAll,
+        Signable, /**< Show only addresses that can sign messages */
+    };
+
+    explicit AddressBookPage(const PlatformStyle *platformStyle, Mode mode, Tabs tab, QWidget *parent = nullptr, AddressFilter address_filter = AddressFilter::ShowAll);
     ~AddressBookPage();
 
     void setModel(AddressTableModel *model);
@@ -52,6 +57,7 @@ public Q_SLOTS:
     AddressTableModel* model{nullptr};
     Mode mode;
     Tabs tab;
+    AddressFilter address_filter;
     QString returnValue;
     AddressBookSortFilterProxyModel *proxyModel;
     QMenu *contextMenu;

src/qt/addresstablemodel.cpp

@@ -229,6 +229,11 @@ QVariant AddressTableModel::data(const QModelIndex &index, int role) const
             return {};
         } // no default case, so the compiler can warn about missing cases
         assert(false);
+    } else if (role == CanSignMessageRole) {
+        const auto destination{DecodeDestination(rec->address.toStdString())};
+        return std::holds_alternative<PKHash>(destination) &&
+               !walletModel->wallet().privateKeysDisabled() &&
+               walletModel->wallet().isSpendable(destination);
     }
     return QVariant();
 }

src/qt/addresstablemodel.h

@@ -39,7 +39,8 @@ class AddressTableModel : public QAbstractTableModel
     };
 
     enum RoleIndex {
-        TypeRole = Qt::UserRole /**< Type of address (#Send or #Receive) */
+        TypeRole = Qt::UserRole, /**< Type of address (#Send or #Receive) */
+        CanSignMessageRole /**< Whether the address can be used for message signing */
     };
 
     /** Return status of edit/insert operation */

src/qt/signverifymessagedialog.cpp

@@ -93,8 +93,7 @@ void SignVerifyMessageDialog::on_addressBookButton_SM_clicked()
 {
     if (model && model->getAddressTableModel())
     {
-        model->refresh(/*pk_hash_only=*/true);
-        AddressBookPage dlg(platformStyle, AddressBookPage::ForSelection, AddressBookPage::ReceivingTab, this);
+        AddressBookPage dlg(platformStyle, AddressBookPage::ForSelection, AddressBookPage::ReceivingTab, this, AddressBookPage::AddressFilter::Signable);
         dlg.setModel(model->getAddressTableModel());
         if (dlg.exec())
         {

src/qt/test/addressbooktests.cpp

@@ -9,15 +9,18 @@
 #include <interfaces/chain.h>
 #include <interfaces/node.h>
 #include <qt/addressbookpage.h>
+#include <qt/addresstablemodel.h>
 #include <qt/clientmodel.h>
 #include <qt/editaddressdialog.h>
+#include <qt/signverifymessagedialog.h>
 #include <qt/optionsmodel.h>
 #include <qt/platformstyle.h>
 #include <qt/qvalidatedlineedit.h>
 #include <qt/walletmodel.h>
 
 #include <key.h>
 #include <key_io.h>
+#include <script/descriptor.h>
 #include <wallet/wallet.h>
 #include <wallet/test/util.h>
 #include <walletinitinterface.h>
@@ -36,6 +39,7 @@ using wallet::CreateMockableWalletDatabase;
 using wallet::RemoveWallet;
 using wallet::WALLET_FLAG_DESCRIPTORS;
 using wallet::WalletContext;
+using wallet::WalletDescriptor;
 
 namespace
 {
@@ -208,6 +212,147 @@ void TestAddAddressesToSendBook(interfaces::Node& node)
     QCOMPARE(table_view->model()->rowCount(), 3);
 }
 
+/**
+ * Test that CanSignMessageRole correctly filters the sign-message address picker:
+ * - watch-only PKHash addresses (no private key) → not signable
+ * - bech32 addresses (not PKHash) → not signable
+ * - spendable PKHash addresses (private key imported) → signable
+ * Also verifies AddressBookPage::AddressFilter::Signable shows only signable addresses.
+ */
+void TestSignableAddressFilter(interfaces::Node& node)
+{
+    TestChain100Setup test;
+    auto wallet_loader = interfaces::MakeWalletLoader(*test.m_node.chain, *Assert(test.m_node.args));
+    test.m_node.wallet_loader = wallet_loader.get();
+    node.setContext(&test.m_node);
+
+    const std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
+        node.context()->chain.get(), "", CreateMockableWalletDatabase());
+
+    {
+        LOCK(wallet->cs_wallet);
+        wallet->SetWalletFlag(WALLET_FLAG_DESCRIPTORS);
+        wallet->SetupDescriptorScriptPubKeyMans();
+
+        // (a) Watch-only PKHash: address in book but no private key → not signable
+        const PKHash watchonly_dest{GenerateRandomKey().GetPubKey()};
+        wallet->SetAddressBook(watchonly_dest, "watchonly", wallet::AddressPurpose::RECEIVE);
+
+        // (b) Bech32 (P2WPKH): not a PKHash destination → not signable
+        const WitnessV0KeyHash bech32_dest{GenerateRandomKey().GetPubKey()};
+        wallet->SetAddressBook(bech32_dest, "bech32", wallet::AddressPurpose::RECEIVE);
+
+        // (c) Spendable PKHash: private key imported via pkh() descriptor → signable
+        CKey legacy_key;
+        legacy_key.MakeNewKey(true);
+        FlatSigningProvider legacy_provider;
+        std::string legacy_err;
+        auto legacy_descs = Parse("pkh(" + EncodeSecret(legacy_key) + ")", legacy_provider, legacy_err, /*require_checksum=*/false);
+        assert(!legacy_descs.empty());
+        WalletDescriptor legacy_w_desc(std::move(legacy_descs[0]), /*creation_time=*/0, /*range_start=*/0, /*range_end=*/1, /*next_index=*/1);
+        QVERIFY(wallet->AddWalletDescriptor(legacy_w_desc, legacy_provider, "", /*internal=*/false));
+        const PKHash legacy_dest{legacy_key.GetPubKey()};
+        wallet->SetAddressBook(legacy_dest, "legacy", wallet::AddressPurpose::RECEIVE);
+    }
+
+    std::unique_ptr<const PlatformStyle> platformStyle(PlatformStyle::instantiate("other"));
+    OptionsModel optionsModel(node);
+    bilingual_str error;
+    QVERIFY(optionsModel.Init(error));
+    ClientModel clientModel(node, &optionsModel);
+    WalletContext& context = *node.walletLoader().context();
+    AddWallet(context, wallet);
+    WalletModel walletModel(interfaces::MakeWallet(context, wallet), clientModel, platformStyle.get());
+    RemoveWallet(context, wallet, /*load_on_start=*/std::nullopt);
+    AddressTableModel* addrModel = walletModel.getAddressTableModel();
+    QVERIFY(addrModel);
+
+    // Only the spendable PKHash should report CanSignMessageRole=true
+    int signable_count = 0;
+    for (int i = 0; i < addrModel->rowCount({}); ++i) {
+        if (addrModel->data(addrModel->index(i, AddressTableModel::Address, {}),
+                            AddressTableModel::CanSignMessageRole).toBool()) {
+            ++signable_count;
+        }
+    }
+    QCOMPARE(signable_count, 1);
+
+    // AddressFilter::Signable must show only the spendable PKHash; no filter shows all
+    AddressBookPage page_all{platformStyle.get(), AddressBookPage::ForSelection, AddressBookPage::ReceivingTab};
+    page_all.setModel(addrModel);
+    AddressBookPage page_signable{platformStyle.get(), AddressBookPage::ForSelection, AddressBookPage::ReceivingTab,
+                                  nullptr, AddressBookPage::AddressFilter::Signable};
+    page_signable.setModel(addrModel);
+
+    auto* table_all      = page_all.findChild<QTableView*>("tableView");
+    auto* table_signable = page_signable.findChild<QTableView*>("tableView");
+    QVERIFY(table_all != nullptr);
+    QVERIFY(table_signable != nullptr);
+    QCOMPARE(table_signable->model()->rowCount(), 1);
+    QVERIFY(table_all->model()->rowCount() >= 3);
+}
+
+/**
+ * Regression test for the stale shared model bug: clicking the address book
+ * button in SignVerifyMessageDialog previously called
+ * WalletModel::refresh(pk_hash_only=true), which replaced the shared
+ * addressTableModel pointer with a new filtered instance. Any other view
+ * (e.g. the Receiving Addresses window) holding that pointer was left stale
+ * and would not reflect addresses added after the picker was opened.
+ *
+ * Directly invokes on_addressBookButton_SM_clicked() — the exact trigger of
+ * the bug — and verifies the shared addressTableModel pointer is unchanged.
+ */
+void TestAddressTableModelStability(interfaces::Node& node)
+{
+    TestChain100Setup test;
+    auto wallet_loader = interfaces::MakeWalletLoader(*test.m_node.chain, *Assert(test.m_node.args));
+    test.m_node.wallet_loader = wallet_loader.get();
+    node.setContext(&test.m_node);
+
+    const std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
+        node.context()->chain.get(), "", CreateMockableWalletDatabase());
+    {
+        LOCK(wallet->cs_wallet);
+        wallet->SetWalletFlag(WALLET_FLAG_DESCRIPTORS);
+        wallet->SetupDescriptorScriptPubKeyMans();
+        wallet->SetAddressBook(PKHash{GenerateRandomKey().GetPubKey()}, "addr1", wallet::AddressPurpose::RECEIVE);
+    }
+
+    std::unique_ptr<const PlatformStyle> platformStyle(PlatformStyle::instantiate("other"));
+    OptionsModel optionsModel(node);
+    bilingual_str error;
+    QVERIFY(optionsModel.Init(error));
+    ClientModel clientModel(node, &optionsModel);
+    WalletContext& context = *node.walletLoader().context();
+    AddWallet(context, wallet);
+    WalletModel walletModel(interfaces::MakeWallet(context, wallet), clientModel, platformStyle.get());
+    RemoveWallet(context, wallet, /*load_on_start=*/std::nullopt);
+
+    // Store the shared model pointer — this is what Receiving Addresses holds
+    AddressTableModel* initial_model = walletModel.getAddressTableModel();
+    QVERIFY(initial_model != nullptr);
+    QCOMPARE(initial_model->rowCount({}), 1);
+
+    SignVerifyMessageDialog svd(platformStyle.get(), nullptr);
+    svd.setModel(&walletModel);
+
+    // Close the address book picker as soon as it opens — it uses exec() so
+    // the timer fires inside that modal event loop
+    QTimer::singleShot(0, []() {
+        for (QWidget* widget : QApplication::topLevelWidgets()) {
+            if (auto* page = qobject_cast<AddressBookPage*>(widget)) page->reject();
+        }
+    });
+
+    // Invoke the exact slot that previously called model->refresh(pk_hash_only=true)
+    QMetaObject::invokeMethod(&svd, "on_addressBookButton_SM_clicked");
+
+    // The shared model pointer must be unchanged — Receiving Addresses is not stale
+    QCOMPARE(walletModel.getAddressTableModel(), initial_model);
+    QCOMPARE(initial_model->rowCount({}), 1);
+}
+
 } // namespace
 
 void AddressBookTests::addressBookTests()
@@ -224,4 +369,6 @@ void AddressBookTests::addressBookTests()
     }
 #endif
     TestAddAddressesToSendBook(m_node);
+    TestAddressTableModelStability(m_node);
+    TestSignableAddressFilter(m_node);
 }

src/qt/walletmodel.cpp

@@ -583,11 +583,6 @@ bool WalletModel::isMultiwallet() const
     return m_node.walletLoader().getWallets().size() > 1;
 }
 
-void WalletModel::refresh(bool pk_hash_only)
-{
-    addressTableModel = new AddressTableModel(this, pk_hash_only);
-}
-
 uint256 WalletModel::getLastBlockProcessed() const
 {
     return m_client_model ? m_client_model->getBestBlockHash() : uint256{};

src/qt/walletmodel.h

@@ -144,8 +144,6 @@ class WalletModel : public QObject
 
     bool isMultiwallet() const;
 
-    void refresh(bool pk_hash_only = false);
-
     uint256 getLastBlockProcessed() const;
 
     // Retrieve the cached wallet balance