When copying a mono LV2 plugin to a stereo track, the
state of the copied mono plugin is copied to the replicated
instance.
However at this point in time PBD::Stateful::ForceIDRegeneration
is still enabled, and the state ID has not been set.
This used to not be an issue. Older versions of liblilv
handle non-existent paths just fine.
However in lilv v0.24.20-10-gdd5e851 `lilv_path_absolute`
was replaced with `zix_canonical_path` which returns NULL
if a state file does not [yet] exist. This lead to a segfault
due to strlen(NULL) in `serd_node_new_file_uri`:
#0 strlen -- SEGV on unknown address 0x000000000000
#1 serd_node_new_file_uri () at /lib/x86_64-linux-gnu/libserd-0.so.0
#2 lilv_state_new_from_file () at /lib/x86_64-linux-gnu/liblilv-0.so.0
#3 ARDOUR::LV2Plugin::set_state(XMLNode const&, int) at ../libs/ardour/lv2_plugin.cc:2320
066df7cc1a