feat(CI): Disallow implicit casting of QByteArray to char* or void*

QByteArray usually holds arbitrary binary data, which can have null
characters or invalid characters when converted to ASCII or UTF8.
Disallow implicit casting for safety, forcing an explicit decision if
the conversion is wanted.

CMakeLists.txt

@@ -102,6 +102,8 @@ if (UNIX AND NOT APPLE)
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-z,relro")
 endif()
 
+add_definitions(-DQT_NO_CAST_FROM_BYTEARRAY)
+
 include(CheckAtomic)
 
 # Use ccache when available to speed up builds.

src/platform/camera/avfoundation.mm

@@ -57,7 +57,7 @@ QVector<VideoMode> avfoundation::getDeviceModes(QString devName)
         return result;
     }
     else {
-        NSString* deviceName = [NSString stringWithCString:devName.toUtf8() encoding:NSUTF8StringEncoding];
+        NSString* deviceName = [NSString stringWithCString:devName.toUtf8().constData() encoding:NSUTF8StringEncoding];
         AVCaptureDevice* device = [AVCaptureDevice deviceWithUniqueID:deviceName];
 
         if (device == nil) {