SCI: ECOQUEST2: nothing happens when the Ecorder displays "printing"

[lwcorp]

I'm not sure if this is even a SCI issue or a more general one (if so, please modify).

So the Ecorder device in this game can actually send text to one's printer (LPT1). It works for example in DOSBox-X (which supports printing), but not in ScummVM. Any attempt to print just secretly creates a file called ecoquest2-prn (no extension) without any indication on the screen other than displaying "Printing" inside the game. Nothing is even mentioned in the console screen.

Steps to reproduce

1. Enter the game's top menu
2. Click the inventory icon
3. Click the hand icon
4. Click the Ecorder
5. Click the Turn On button
6. Click Down until reaching "Print My Fact Sheet"
7. Click the Enter button
8. Click Up to accept printing
9. Click the Enter button
10. See the game displaying "Printing" for a couple of seconds

Expected outcome
Options:

• Print

or

• Save to a PDF file

or

• At least indicate on screen this can't be done (at least in console)

Actual result
Nothing seemingly happens but secretly a file called ecoquest2-prn (no extension) is being created

[lwcorp]

This screenshot isn't supported in alt+s due to the blinking state of Printing (which just comes out blank blue screen)

[lwcorp]

The printing outcome when playing not via ScummVM (the player's name is modifiable due to relevant Ecorder setting)

[lwcorp]

The file ScummVM secretly creates (without an extension)

[lwcorp]

Savegame with the Ecorder

[lwcorp]

Savegame in the original interpreter (with the Ecorder), which you can try in an emulator like DOSBox-X that supports printing

[bluegr]

We don't support printing in ScummVM, plus this is an extremely rare case where a SCI game is actually trying to perform printing.

This has now been fixed in commit 25a7fc6ab1cd386b1640a30a755f41e09bf3db4f - the game no longer tries to perform any printing in that place.

[lwcorp]

So it's better than before (since the file wasn't really accessible), but still a shame since it does work in printing aware DOSBox variants like DOSBox-X which open source code can be utilized for this...

But 2 questions remain though:

1. What happens following this fix? What does return SIGNAL_REG; do?
2. What's the point of displaying Printing while not printing? Why not writing something else like "Printing failed"?