I have a custom xkb symbols file which looks as follows:
// modify the basic German layout to have polish characters
default partial alphanumeric_keys
xkb_symbols "basic" {
include "de(basic)"
name[Group1]="Germany - with polish characters";
key <AD03> { [ e, E, eogonek, Eogonek ] };
key <AD09> { [ o, O, oacute, Oacute ] };
key <AC01> { [ a, A, aogonek, Aogonek ] };
key <AC02> { [ s, S, sacute, Sacute ] };
key <AD06> { [ z, Z, zabovedot, Zabovedot ] };
key <AB02> { [ x, X, zacute, Zacute ] };
key <AB03> { [ c, C, cacute, Cacute ] };
key <AB06> { [ n, N, nacute, Nacute ] };
};
The name of the file is depl. I copy the file to /usr/share/X11/xkb/symbols and it works with setxkbmap depl.
However, I also tried to add the respective menu entries in the "Text Entry" customization. I have modified the file /usr/share/X11/xkb/rules/evdev.xml and added the following section:
<layout>
<configItem>
<name>depl</name>
<shortDescription>depl</shortDescription>
<description>German (with Polish characters)</description>
<languageList>
<iso639Id>ger</iso639Id>
</languageList>
</configItem>
</layout>
I have then reconfigured the xkb data with sudo dpkg-reconfigure xkb-data.
It works in as much as that the new layout appears as a viable option in the Text Entry dialog, it can be added to the list of dialogs and is visible in the application indicator:
However, it does not work, the new symbols are not loaded. No errors are reported in /var/log/Xorg.0.log.