Comment 11 for bug 1969396

Now I have tested a bit more back and forth, and here is a new attempt to describe the nature of the issue:

Whether Right Alt works as the compose key or not depends mostly on where in the list of input sources the keyboard layout in effect is present.

If the layout in effect is the first one in the list, Right Alt works fine as compose key. This is true whether Alternate Characters Key is switched off or set to "None". (No problem with "English (Dvorak, alt., intl.)" either, in other words, if that layout is first in the list of input sources.)

If the layout in effect is further down in the list, Right Alt may or may not work as compose key. Not sure about the exact pattern here.

As regards Alternate Characters Key, I notice a marginal impact. If the English (US) layout is not the first layout in the list, Right Alt works as compose key with that layout if Alternate Characters Key is switched off, but not if it's set to "None". It should be noted that English (US) does not set Right Alt to the 3rd level key by default.

Steve, does the above description reflect your observations too?

Over to the question whether this is a g-c-c bug to some extent. I still think that g-c-c sets sensible options, and that the unexpected behavior is rather an XKB issue. The reason why Alternate Characters Key sets "lv3:ralt_alt" is that it assumes that a user who picks something else but Right Alt wants to be able to use Right Alt as any Alt key.

OTOH, given this issue wrt Right Alt as compose key, you can argue that g-c-c should better not provide Right Alt as a compose key option...