From f6933a88681cd57fd3d08db290ff4966eda810ad Mon Sep 17 00:00:00 2001
From: Janek Bevendorff <janek@jbev.net>
Date: Tue, 24 Oct 2017 15:25:38 +0200
Subject: [PATCH] Ensure that YubiKey is only polled once, even if showEvent()
 is called twice

---
 src/gui/DatabaseOpenWidget.cpp | 16 ++++++++++++----
 src/gui/DatabaseOpenWidget.h   |  1 +
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/gui/DatabaseOpenWidget.cpp b/src/gui/DatabaseOpenWidget.cpp
index ee0e9de2..e487f97c 100644
--- a/src/gui/DatabaseOpenWidget.cpp
+++ b/src/gui/DatabaseOpenWidget.cpp
@@ -95,11 +95,16 @@ void DatabaseOpenWidget::showEvent(QShowEvent* event)
     m_ui->editPassword->setFocus();
 
 #ifdef WITH_XC_YUBIKEY
-    connect(YubiKey::instance(), SIGNAL(detected(int,bool)), SLOT(yubikeyDetected(int,bool)), Qt::QueuedConnection);
-    connect(YubiKey::instance(), SIGNAL(detectComplete()), SLOT(yubikeyDetectComplete()), Qt::QueuedConnection);
-    connect(YubiKey::instance(), SIGNAL(notFound()), SLOT(noYubikeyFound()), Qt::QueuedConnection);
+    // showEvent() may be called twice, so make sure we are only polling once
+    if (!m_yubiKeyBeingPolled) {
+        connect(YubiKey::instance(), SIGNAL(detected(int, bool)), SLOT(yubikeyDetected(int, bool)),
+                Qt::QueuedConnection);
+        connect(YubiKey::instance(), SIGNAL(detectComplete()), SLOT(yubikeyDetectComplete()), Qt::QueuedConnection);
+        connect(YubiKey::instance(), SIGNAL(notFound()), SLOT(noYubikeyFound()), Qt::QueuedConnection);
 
-    pollYubikey();
+        pollYubikey();
+        m_yubiKeyBeingPolled = true;
+    }
 #endif
 }
 
@@ -110,6 +115,7 @@ void DatabaseOpenWidget::hideEvent(QHideEvent* event)
 #ifdef WITH_XC_YUBIKEY
     // Don't listen to any Yubikey events if we are hidden
     disconnect(YubiKey::instance(), 0, this, 0);
+    m_yubiKeyBeingPolled = false;
 #endif
 }
 
@@ -311,10 +317,12 @@ void DatabaseOpenWidget::yubikeyDetectComplete()
     m_ui->checkChallengeResponse->setEnabled(true);
     m_ui->buttonRedetectYubikey->setEnabled(true);
     m_ui->yubikeyProgress->setVisible(false);
+    m_yubiKeyBeingPolled = false;
 }
 
 void DatabaseOpenWidget::noYubikeyFound()
 {
     m_ui->buttonRedetectYubikey->setEnabled(true);
     m_ui->yubikeyProgress->setVisible(false);
+    m_yubiKeyBeingPolled = false;
 }
diff --git a/src/gui/DatabaseOpenWidget.h b/src/gui/DatabaseOpenWidget.h
index a7691a91..aade111c 100644
--- a/src/gui/DatabaseOpenWidget.h
+++ b/src/gui/DatabaseOpenWidget.h
@@ -73,6 +73,7 @@ protected:
     QString m_filename;
 
 private:
+    bool m_yubiKeyBeingPolled = false;
     Q_DISABLE_COPY(DatabaseOpenWidget)
 };