McGroupBitMask not set

[darkfader]

In stack code: (STM32Cube_FW_WL_V1.2.0 based on LoRaMac-node)

                if (mcpsIndication->Multicast == 1) {
                    // Message received on a multicast address
                    // Check McGroupBitMask
                    uint8_t groupId = LoRaMacMcChannelGetGroupId(mcpsIndication->DevAddress);
                    if ((groupId == 0xFF) ||
                        ((FragSessionData[fragIndex].FragGroupData.FragSession.Fields.McGroupBitMask & (1 << groupId)) == 0)) {
                        // Ignore message
                        cmdIndex = mcpsIndication->BufferSize;
                        break;
                    }
                }

My groupId was 0 but apparently required a bit to be set in McGroupBitMask. To make it work for my case, I added McGroupBitMask to the fragmentation session setup in fuota.go.

					FragSession: fragmentation.FragSessionSetupReqPayloadFragSession{
						FragIndex: d.opts.FragmentationSessionIndex,
						McGroupBitMask: [4]bool{true, false, false, false},   // assume groupId to be 0 :)
					},