From 4065a6691f35913dd7deb5e87b0f67bb12c20672 Mon Sep 17 00:00:00 2001
From: Tony Mountifield <tony@mountifield.org>
Date: Thu, 30 Jul 2026 17:58:29 +0100
Subject: [PATCH 1/3] Fixes for a crash suggested by AI in #3845

---
 src/client.cpp    | 3 +--
 src/clientdlg.cpp | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/client.cpp b/src/client.cpp
index fb9bab5478..b62a541f41 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -853,7 +853,7 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
 
     // audio device notifications can come at any time and they are in a
     // different thread, therefore we need a mutex here
-    MutexDriverReinit.lock();
+    QMutexLocker locker ( &MutexDriverReinit );
     {
         // in older QT versions, enums cannot easily be used in signals without
         // registering them -> workaroud: we use the int type and cast to the enum
@@ -888,7 +888,6 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
             Sound.Start();
         }
     }
-    MutexDriverReinit.unlock();
 
     // inform GUI about the sound card device change
     emit SoundDeviceChanged ( strError );
diff --git a/src/clientdlg.cpp b/src/clientdlg.cpp
index b102c34724..9c3455e477 100644
--- a/src/clientdlg.cpp
+++ b/src/clientdlg.cpp
@@ -866,7 +866,7 @@ void CClientDlg::OnCLVersionAndOSReceived ( CHostAddress InetAddr, COSUtil::EOpS
         {
             // show the label and hide it after one minute again
             lblUpdateCheck->show();
-            QTimer::singleShot ( 60000, [this]() { lblUpdateCheck->hide(); } );
+            QTimer::singleShot ( 60000, this, [this]() { lblUpdateCheck->hide(); } );
         }
 #endif
     }

From 3abd4f637a65b23df1f0a0b424f706d432d2ae78 Mon Sep 17 00:00:00 2001
From: Tony Mountifield <tony@mountifield.org>
Date: Fri, 31 Jul 2026 22:54:24 +0100
Subject: [PATCH 2/3] Catch exception when initialising sound device

---
 src/client.cpp | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/client.cpp b/src/client.cpp
index b62a541f41..f3b83a89a7 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -738,6 +738,8 @@ void CClient::SetAudioChannels ( const EAudChanConf eNAudChanConf )
 
 QString CClient::SetSndCrdDev ( const QString strNewDev )
 {
+    QString strError = "";
+
     // if client was running then first
     // stop it and restart again after new initialization
     const bool bWasRunning = Sound.IsRunning();
@@ -746,16 +748,23 @@ QString CClient::SetSndCrdDev ( const QString strNewDev )
         Sound.Stop();
     }
 
-    const QString strError = Sound.SetDev ( strNewDev );
+    try
+    {
+        strError = Sound.SetDev ( strNewDev );
 
-    // init again because the sound card actual buffer size might
-    // be changed on new device
-    Init();
+        // init again because the sound card actual buffer size might
+        // be changed on new device
+        Init();
 
-    if ( bWasRunning )
+        if ( bWasRunning )
+        {
+            // restart client
+            Sound.Start();
+        }
+    }
+    catch ( const CGenErr& generr )
     {
-        // restart client
-        Sound.Start();
+        strError = generr.GetErrorText();
     }
 
     // in case of an error inform the GUI about it
@@ -854,6 +863,7 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
     // audio device notifications can come at any time and they are in a
     // different thread, therefore we need a mutex here
     QMutexLocker locker ( &MutexDriverReinit );
+    try
     {
         // in older QT versions, enums cannot easily be used in signals without
         // registering them -> workaroud: we use the int type and cast to the enum
@@ -888,6 +898,10 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
             Sound.Start();
         }
     }
+    catch ( const CGenErr& generr )
+    {
+        strError = generr.GetErrorText();
+    }
 
     // inform GUI about the sound card device change
     emit SoundDeviceChanged ( strError );

From d6855af5748998ab79a40f4926c200960211e54d Mon Sep 17 00:00:00 2001
From: Tony Mountifield <tony@mountifield.org>
Date: Sat, 1 Aug 2026 14:09:39 +0100
Subject: [PATCH 3/3] Add explanatory comment to each new try block

---
 src/client.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/client.cpp b/src/client.cpp
index f3b83a89a7..f069208da7 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -748,6 +748,8 @@ QString CClient::SetSndCrdDev ( const QString strNewDev )
         Sound.Stop();
     }
 
+    // Jamulus sound drivers for different platforms may throw CGenErr exception
+    // on error condition. Catch it here as exceptions must not escape from a Qt slot.
     try
     {
         strError = Sound.SetDev ( strNewDev );
@@ -863,6 +865,9 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
     // audio device notifications can come at any time and they are in a
     // different thread, therefore we need a mutex here
     QMutexLocker locker ( &MutexDriverReinit );
+
+    // Jamulus sound drivers for different platforms may throw CGenErr exception
+    // on error condition. Catch it here as exceptions must not escape from a Qt slot.
     try
     {
         // in older QT versions, enums cannot easily be used in signals without