Backport of "avmux: fix segfault when a plugin's long_name is NULL" into 1.18
Backport of !114 (merged) "avmux: fix segfault when a plugin's long_name is NULL".
Commits:
- ad7f7c87 avmux: fix segfault when a plugin's long_name is NULL
Backport of !114 (merged) "avmux: fix segfault when a plugin's long_name is NULL".
Commits: