Sync local clipboard to a tab when it becomes visible

Only the visible tab syncs the clipboard, but a tab in the background
missed local clipboard changes and kept a stale remote clipboard when
switched to, so with two RDP/VNC sessions only the one last copied in
worked. A tab now pushes the current local clipboard to its remote on
show.

Bump version to v2026.9.26.2.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/session_tab.cpp

@@ -28,6 +28,7 @@
 #include <QComboBox>
 #include <QProcessEnvironment>
 #include <QPushButton>
+#include <QShowEvent>
 #include <QScrollArea>
 #include <QThread>
 #include <QTimer>
@@ -799,6 +800,26 @@ void SessionTab::onBackendRemoteClipboardTextChanged(const QString& text)
 }
 
 void SessionTab::onSystemClipboardChanged()
+{
+    const QClipboard* clipboard = QApplication::clipboard();
+    const QString text = clipboard->mimeData()->hasText() ? clipboard->text() : QString();
+
+    // Suppress only the change we caused ourselves, and only briefly. The
+    // old "same as last synced text" check had no expiry: once a send was
+    // lost (channel not ready, remote clipboard changed to something we
+    // never saw) copying that same text again did nothing, indefinitely.
+    constexpr qint64 kEchoWindowMs = 1000;
+    const bool isEcho = !m_pendingClipboardEcho.isEmpty() && text == m_pendingClipboardEcho
+        && QDateTime::currentMSecsSinceEpoch() - m_pendingClipboardEchoMs < kEchoWindowMs;
+    m_pendingClipboardEcho.clear();
+    if (isEcho) {
+        return;
+    }
+
+    pushLocalClipboardToRemote();
+}
+
+void SessionTab::pushLocalClipboardToRemote()
 {
     if (!m_clipboardSyncSupported || m_state != SessionState::Connected || !isVisible()) {
         return;
@@ -814,22 +835,16 @@ void SessionTab::onSystemClipboardChanged()
         return;
     }
 
-    // Suppress only the change we caused ourselves, and only briefly. The
-    // old "same as last synced text" check had no expiry: once a send was
-    // lost (channel not ready, remote clipboard changed to something we
-    // never saw) copying that same text again did nothing, indefinitely.
-    constexpr qint64 kEchoWindowMs = 1000;
-    const bool isEcho = !m_pendingClipboardEcho.isEmpty() && text == m_pendingClipboardEcho
-        && QDateTime::currentMSecsSinceEpoch() - m_pendingClipboardEchoMs < kEchoWindowMs;
-    m_pendingClipboardEcho.clear();
-    if (isEcho) {
-        return;
-    }
-
     emit requestSetClipboardText(text);
     appendEvent(QStringLiteral("Clipboard: sending %1 characters to remote.").arg(text.size()));
 }
 
+void SessionTab::showEvent(QShowEvent* event)
+{
+    QWidget::showEvent(event);
+    pushLocalClipboardToRemote();
+}
+
 void SessionTab::setupUi()
 {
     auto* rootLayout = new QVBoxLayout(this);

src/session_tab.h

@@ -24,6 +24,7 @@ class QComboBox;
 class QLabel;
 class QPushButton;
 class QScrollArea;
+class QShowEvent;
 class KodoTerm;
 
 struct SessionUiPreferences
@@ -99,6 +100,11 @@ signals:
     void requestSetClipboardText(const QString& text);
     void requestProvideUsername(const QString& username);
 
+protected:
+    // A tab that wasn't in front while the local clipboard changed missed
+    // that change (only the visible tab syncs), so catch it up on show.
+    void showEvent(QShowEvent* event) override;
+
 private slots:
     void onBackendStateChanged(SessionState state, const QString& message);
     void onBackendEventLogged(const QString& message);
@@ -166,6 +172,7 @@ private:
                             std::function<void(std::optional<QString>)> callback,
                             bool maskInput = true);
     void hidePasswordPrompt();
+    void pushLocalClipboardToRemote();
     bool validateProfileForConnect();
     void appendEvent(const QString& message);
     void setState(SessionState state, const QString& message);