mc-4.8.0-56-g16d1abf: save of some learned keys is broken

[bircoph]

Hello,

recent git snapshot brokes key binding saving.
Midnight Commander was build as follows:

GNU Midnight Commander 4.8.0-56-g16d1abf
Built with GLib 2.30.1
Using the S-Lang library with terminfo database
With builtin Editor
With subshell support as default
With support for background operations
With mouse support on xterm
With support for X11 events
With internationalization support
With multiple codepages support
Virtual File Systems: cpiofs, tarfs, sfs, extfs, ftpfs, fish
Data types: char: 8; int: 32; long: 64; void *: 64; size_t: 64; off_t: 64;

I use xterm + screen + mc.

For 13 <= n <=20 Fn keys I map Fn as S-F(n-10) (e.g. F13 as Shift-F3), this results in the following keymap on the old mc (4.8.0-pre1):

[terminal:screen]
f13=\\e[1\;2R
f14=\\e[1\;2S
f15=\\e[15\;2~
f16=\\e[17\;2~
f17=\\e[18\;2~
f18=\\e[19\;2~
f19=\\e[20\;2~
f20=\\e[21\;2~

Please note, that this keymap loads well with both new and old mc versions.
But new mc snapshot saves these keys as follows:

[terminal:screen]
f13=\\e[1\\;2R
f14=\\e[1\\;2S
f15=\\e[15\\;2~
f16=\\e[17\\;2~
f17=\\e[18\\;2~
f18=\\e[19\\;2~
f19=\\e[20\\;2~
f20=\\e[21\\;2~

It inserts extra \ before ; and fails to load its own config, which results in badly broken key binding for affected keys.

[bircoph]

Good 4.8.0-pre1 was indeed some other git commit (though mc -V doesn't report which one).
Git tag 4.8.0-pre1 is also broken, good version is 4.7.5.1. I'll try to bisect the bug.

[bircoph]

commit b375236b536e341530e14bcb287da6566d586732 causes this problem

[bircoph]

Reverting changes in lib/mcconfig/set.c and src/learn.c from this commit fixes my problem, but reopens bug 2544.

I do not know how to fix them both, but b375236b536e341530e14bcb287da6566d586732 is definitely not a proper fix.

[bircoph]

The following patch fixes the bug by adding special function to set raw value, but not a raw string. It looks like current function can't handle both search string and escaped key bindings, so new function is added to aid keybindnigs.

Patch is attached. OK to apply?

[bircoph]

fix keybindings save

[angel_il]

branch: ​2676_learn_f13-f20_fix (parent: master)

please review

[angel_il]

fixed: 5cc8114d3328a658bcf0c2cd88d0b1c940d1e415

[andrew_b]

Cherry-picked to 4.7.5-stable.
changeset:85ff690d36c8ec72fa1f4da9e189cf9fb3f47efc