Linux console + unsupported skin => cons.saver saves the wrong contents

[egmontkob]

Is there an existing issue for this?

• I have searched the existing issues

Midnight Commander version and build configuration

4.8.33, git

Operating system

Linux

Is this issue reproducible using the latest version of Midnight Commander?

• I confirm the issue is still reproducible with the latest version of Midnight Commander

How to reproduce

On the Linux virtual terminal (console), start up mc with a skin that's not supported there (wants to use 256 or 16M colors).

Dismiss the error box.

Quit mc.

Expected behavior

Previous contents of the terminal restored.

Actual behavior

The error box about the incompatible skin restored.

Additional context

cons.saver should save the contents first, then we should present the error box.

Interestingly, mc in graphical terminals doesn't suffer from this problem. I'd have expected cons.saver to save-restore exactly when we're switching to/from the alternate screen in graphical terminals, as it's pretty much cons.saver's goal to be a substitute for this missing feature of the console.