file "slot" in FILE_OPEN, FILE_READ inconsistencies in firmware and emulation

[bspruck]

The slot cannot be set for files. There is no FILE_SLOT command. For files slot is always -1:

8bit-Hub/Firmware/Hub-Mega2560/Hub-Mega2560.ino

Line 624 in 8208f6e

packet_t *packet = getPacket(comInCMD, slot);

Unluckily, FILE_OPEN used the file ID as slot number when pushing the packet, thus this value cannot be read

8bit-Hub/Firmware/Hub-Mega2560/Hub-Mega2560.ino

Line 1421 in 8208f6e

pushPacket(HUB_FILE_OPEN, comInBuffer[0]);

Two solutions:

• fix this to be -1 (like in FILE_READ)

  8bit-Hub/Firmware/Hub-Mega2560/Hub-Mega2560.ino

  Line 1437 in 8208f6e

  pushPacket(HUB_FILE_READ, -1);

• add a FILE_SLOT command, and change FILE read to use the file slot.

In the handy emulation code this is broken as well. But here both functions use a slot number.