Fix extensions loading/initializing even when entry point fails

[mihe]

This fixes an apparent bug with the loading of extensions, where even if false is returned from the extension's entry point (here) the extension will still be considered successfully loaded by GDExtensionManager (here) due to the p_extension parameter pointing to a valid instance even after the entry point has reported a failure. This also results in it calling the extension module initalizer function even after its entry point has failed, which doesn't seem right.

This also has the unfortunate side effect of preventing any actual error messages from being emitted to the editor log as a result of the failure in the extension entry point, since EditorLog is initialized as part of Main::start(), rather than Main::setup() where all the extension initialization happens. Currently you're able to see editor logs/errors for things like compatibility_minimum due to the fact that any loading of extensions gets retried as part of EditorFileSystem::_scan_extensions, but this will only ever actually be retried if the loading failed in the first place, which it doesn't without the change in this PR.

CC: @dsnopek

[mihe]

@dsnopek I also noticed that the library itself doesn't get closed when the entry point fails, leading to the library still technically being loaded by the process and thus locked on Windows, preventing the cleanup here from happening properly. I can throw that into this PR if you want.

[dsnopek]

Thanks!

I also noticed that the library itself doesn't get closed when the entry point fails, leading to the library still technically being loaded by the process and thus locked on Windows

Eep, yes, it'd be great if you could add that to this PR as well!

[mihe]

Eep, yes, it'd be great if you could add that to this PR as well!

Done.

Also, as an aside, I think the UX for when an extension fails to load should probably be looked over. It currently feels quite aggressive in the way it shows you not only a modal popup saying what extension failed to load, but also multiple toast messages. Not only that, it ends up doing this every time it scans for extensions, which seems to be quite frequently, which leads to the modal popup becoming quite annoying. I feel like ditching the modal popup would go a long way, since it's somewhat redundant with all the other errors being emitted, although I'm not entirely sure where it's originating from.

[dsnopek]

Thanks, this looks good to me!

Also, as an aside, I think the UX for when an extension fails to load should probably be looked over. It currently feels quite aggressive in the way it shows you not only a modal popup saying what extension failed to load, but also multiple toast messages.

I agree, the "toast messages" are probably enough. Something to address in another PR :-)

[akien-mga]

Thanks!