Changed so that multiple halt and convoy dialogs are saved

[RESTRICTED ACCOUNT]

Many players are inconvenienced by the fact that they have multiple convoy info open but only 1 is restored when they reboot simutrans from an auto-save. (´・ω・｀)
This seems like a bug. I guess that the implementation of some code was forgotten for a long time.
Because there is a large gap between magic_convoi_info/magic_halt_info and the next magic number, it seems that save multiple dialogs is intended.

Code Select Expand

    // magic numbers with big jumps between them
    magic_convoi_info,
    magic_UNUSED_convoi_detail = magic_convoi_info          + 0x10000, // unused range
    magic_halt_info            = magic_UNUSED_convoi_detail + 0x10000,
    magic_UNUSED_halt_detail  = magic_halt_info            + 0x10000, // unused range
I made a patch to change this and tested it with extended, but it doesn't seem to cause any problems. It doesn't look like the save size will be large.
May I ask if there was any intention?

I think the patch I attached does that in standard.

[prissi]

I think indeed all convoi dialogs should survive a svae/load circle, when a new client joins.

Incorporated in r 10759, thanks.