winrt: Fix potential crash when querying for resolutionsv5.6.1-1v5.6.1

c84bdf63e4de16586eda3c45d5c3c3b2dc4fe089 introduced a potential crash on
Windows Phone as querying for photo resolutions still might return video
properties. As a result, querying for ImageEncodingProperties will fail
and the function returns no resolution at all causing an assert later
on.

Instead of checking for the stream type passed to
getMediaStreamResolutions we have to check for the property type of the
list itself.

Task-number: QTBUG-53714
Change-Id: I7bfc48ebf1fef4f9165135af604ce6c91a418438
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 9 insertions, 6 deletions

diff --git a/src/plugins/winrt/qwinrtcameracontrol.cpp b/src/plugins/winrt/qwinrtcameracontrol.cpp
index 5c41987a0..1eaf27ca5 100644
--- a/src/plugins/winrt/qwinrtcameracontrol.cpp
+++ b/src/plugins/winrt/qwinrtcameracontrol.cpp
@@ -101,7 +101,13 @@ HRESULT getMediaStreamResolutions(IMediaDeviceController *device,
         ComPtr<IMediaEncodingProperties> properties;
         hr = (*propertiesList)->GetAt(index, &properties);
         Q_ASSERT_SUCCEEDED(hr);
-        if (type == MediaStreamType_VideoRecord || type == MediaStreamType_VideoPreview) {
+        HString propertyType;
+        hr = properties->get_Type(propertyType.GetAddressOf());
+        Q_ASSERT_SUCCEEDED(hr);
+
+        const HStringReference videoRef = HString::MakeReference(L"Video");
+        const HStringReference imageRef = HString::MakeReference(L"Image");
+        if (propertyType == videoRef) {
             ComPtr<IVideoEncodingProperties> videoProperties;
             hr = properties.As(&videoProperties);
             Q_ASSERT_SUCCEEDED(hr);
@@ -111,13 +117,10 @@ HRESULT getMediaStreamResolutions(IMediaDeviceController *device,
             hr = videoProperties->get_Height(&height);
             Q_ASSERT_SUCCEEDED(hr);
             resolutions->append(QSize(width, height));
-        } else if (type == MediaStreamType_Photo) {
+        } else if (propertyType == imageRef) {
             ComPtr<IImageEncodingProperties> imageProperties;
             hr = properties.As(&imageProperties);
-            // Asking for Photo also returns video resolutions in addition
-            // We skip those, as we are only interested in image Type
-            if (FAILED(hr) || !imageProperties)
-                continue;
+            Q_ASSERT_SUCCEEDED(hr);
             UINT32 width, height;
             hr = imageProperties->get_Width(&width);
             Q_ASSERT_SUCCEEDED(hr);