When destroying a frame handle, the previous logic would copy the
shared_ptr in the userdata and then free it twice (once explicitly
and once at the end of the function), which is actually UB, even
if if worked fine so far. This commit now ensures that it's the
actual userdata's shared_ptr that's freed in the gc function.
This would cause an assertion failure in functions like lua_for_each
when the given closure throws an error and thus leaves some values on
the stack. This can make Aegisub crash entirely instead of just catching
and reporting the error. Instead, these stack_checks can be done
manually.
Putting this logic for delaying changes in the TextSelectionController
isn't the cleanest, but all attempts at saving this state somewhere in
the Lua API instead turned out even worse. Also, the logic for inverted
selections probably does belong in there.
Add a new Project class which is responsible for everything related to
opening and closing audio, video, subtitles, timecodes and keyframes.
This pulls almost everything not directly related to playing audio/video
out of the audio and video controllers, pulls more crap out of
FrameMain, and happens to make things a little simpler in the process.
In preparation for switching to LuaJIT, which doesn't support PUC Lua's
thing of using C++ exceptions for lua_error.
Requires replacing all uses of lua_error (and things calling lua_error)
with custom versions that throw an exception instead and adding an
exception -> lua error wrapper at all C++ -> Lua boundaries.
This requires shuffling a bunch of stuff around to get a CLI lua
executable that uses an automation-like environment, but that's
something that'll be nice to have in the future anyway.
Busted indirectly depends on lfs and we currently can't use external
binary modules, so add a copy of lfs to the repo and build it with
Aegisub.
Aegisub needs Lua built as C++ (for stack unwinding on errors). No one
packages it like that, so at the moment we can't actually use systme
packages for Lua.
Fixes a bunch of memory leaks on Automation errors.