As of currently, when an xcursor theme depends on itself or another theme
that will eventually depend on it, `xcursor_load_theme` will recurse
infinitely while processing the inherits.
This change introduces a stack-allocated linked list of visited nodes
by name, and skips any already visited nodes in the inherit list.
Side effects:
* Since the linked list is stack-allocated, there is a potential for an
overflow if there is a very long list of dependencies. If this turns out
to be a legitimate concern, the linked list is trivial to convert to
being heap-allocated.
* There is an existing linked list (technically doubly linked list)
implementation in the wayland codebase. As of currently, the xcursor
codebase does not refer to it. Consequently, this change writes a
minimal single linked list implementation to utilize directly.
This changeset is based on the merge request in wayland/wayland!376.
The xcursor code is mostly shared between the two.
This changeset diverges the files slightly due to stylistic differences
between the repositories, but the logic is identical.
Signed-off-by: Chloé Vulquin <toast@bunkerlabs.net>
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