libgnt/libgnt

Make all destroy functions multi-call safe.

2020-09-27, Elliott Sales de Andrade
ffb6069167a2
Make all destroy functions multi-call safe.

Also, fix an incorrect name for a dispose vfunc.

Testing Done:
Compile only, and the test from LIBGNT-11.

Reviewed at https://reviews.imfreedom.org/r/141/
plugindir = get_option('libdir') / 'gnt3'
irssi = library('irssi', 'irssi.c',
dependencies : [ncurses, gobject, libgnt_dep],
name_prefix : '',
install : true, install_dir : plugindir)
s = library('s', 's.c',
dependencies : [ncurses, gobject, libgnt_dep],
name_prefix : '',
install : true, install_dir : plugindir)