Fix USB permission flow on Android 12+ - #1
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UsbHelper.requestPermission() relies on UsbManager mutating the PendingIntent it broadcasts back to us so we can read EXTRA_DEVICE and EXTRA_PERMISSION_GRANTED. On Android 12 (API 31) PendingIntents must declare mutability explicitly, and on Android 13 (API 33) runtime-registered receivers must declare export-ness. Without these, the PendingIntent registration is rejected on API 31+ with IllegalArgumentException, the receiver registration is rejected on API 33+ with SecurityException, and (when an immutable PendingIntent is used as a workaround) the permission broadcast arrives with a null EXTRA_DEVICE and the flow stalls silently. This change: - Adds FLAG_MUTABLE to the USB_PERMISSION PendingIntent on Build.VERSION_CODES.S and above. FLAG_IMMUTABLE is wrong here: UsbManager needs to attach EXTRA_DEVICE and EXTRA_PERMISSION_GRANTED to the intent before broadcasting it back, which an immutable PendingIntent forbids. - Passes Context.RECEIVER_NOT_EXPORTED to registerReceiver on Build.VERSION_CODES.TIRAMISU and above. The USB_PERMISSION action is delivered by the system to our own process; not-exported is the correct choice and is required on API 33+. - Defensively ignores broadcasts whose action or EXTRA_DEVICE is null, and clears mPermissionPending in the USB_PERMISSION case so a swallowed grant cannot leave the helper stuck refusing further permission requests. Verified on Android 13 (DUDU7 head unit, UNISOC UMS9620, SDK 33) with a 16C0:05DC USB DAB dongle: the USB permission grant path (USB_DEVICE_ATTACHED -> requestPermission -> permission granted -> openDevice) now completes without exception. Pre-fix, the same flow failed at the PendingIntent / registerReceiver call sites on Android 12+ / 13+ respectively. File licence is unchanged (Apache-2.0, IRT GmbH 2018).
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UsbHelper.requestPermission() relies on UsbManager mutating the PendingIntent it broadcasts back to us so we can read EXTRA_DEVICE and EXTRA_PERMISSION_GRANTED. On Android 12 (API 31) PendingIntents must declare mutability explicitly, and on Android 13 (API 33) runtime-registered receivers must declare export-ness. Without these, the PendingIntent registration is rejected on API 31+ with IllegalArgumentException, the receiver registration is rejected on API 33+ with SecurityException, and (when an immutable PendingIntent is used as a workaround) the permission broadcast arrives with a null EXTRA_DEVICE and the flow stalls silently.
This change:
Verified on Android 13 (DUDU7 head unit, UNISOC UMS9620, SDK 33) with a 16C0:05DC USB DAB dongle: the USB permission grant path (USB_DEVICE_ATTACHED -> requestPermission -> permission granted -> openDevice) now completes without exception. Pre-fix, the same flow failed at the PendingIntent / registerReceiver call sites on Android 12+ / 13+ respectively.
File licence is unchanged (Apache-2.0, IRT GmbH 2018).