QWindowsMediaDevices: Fix potential null-pointer-access

It seems sometimes IMMDeviceEnumerator::GetDefaultAudioEndpoint() may return null device even when succeeded. It's probably a bug in MS Core Audio. So we'll check this explicitly to prevent null-pointer-access.

Fixes: QTBUG-108898
Change-Id: Iba1e6673f12a3dafd80f3de11e40babeb1e21e35
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
(cherry picked from commit 9f7eb2bacee57bf95f975f97d72e98d9ca19714e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/multimedia/windows/qwindowsmediadevices.cpp b/src/multimedia/windows/qwindowsmediadevices.cpp
index b01ac5fa5..fcad8bab7 100644
--- a/src/multimedia/windows/qwindowsmediadevices.cpp
+++ b/src/multimedia/windows/qwindowsmediadevices.cpp
@@ -208,10 +208,11 @@ QList<QAudioDevice> QWindowsMediaDevices::availableDevices(QAudioDevice::Mode mo
         LPWSTR id = nullptr;
         QString sid;
 
-        if (SUCCEEDED(m_deviceEnumerator->GetDefaultAudioEndpoint(dataFlow, ERole::eMultimedia, dev.address()))
-            && SUCCEEDED(dev->GetId(&id))) {
-            sid = QString::fromWCharArray(id);
-            CoTaskMemFree(id);
+        if (SUCCEEDED(m_deviceEnumerator->GetDefaultAudioEndpoint(dataFlow, ERole::eMultimedia, dev.address()))) {
+            if (dev && SUCCEEDED(dev->GetId(&id))) {
+                sid = QString::fromWCharArray(id);
+                CoTaskMemFree(id);
+            }
         }
         return sid.toUtf8();
     }();