GetInfo(67), GetInfo(54)

It seems that that is still empty when a plugin is loaded. Thus returns ".\". It seems to me that this is unintentional since in later stages (i. e. when the world is connected to and running) these function calls return different and correct values in the same plugin.
So I think this could be a minor bug. I would love to have clarification on that one, maybe I am just using the wrong number for what I tried to do.
I stumbled over this when just wanting to load a background picture for different worlds from a plugin they each could use. I tried to define the automagical path for this as which should then yield something similar to However, I got instead, as described, and thus failed to load the image.
I patched this using for now, but it seems quite wrong to have to do this and I guess things would break if I moved the world with its image subfolder to a different location...

Where are you putting that code? Is it loose in the script area of the plugin (not within any function)? If so, maybe try putting it in an OnPluginInstall callback. I know that a lot of things probably aren't "ready" when the plugin itself is just loaded; generally that's the time when function definitions are created and global variables are prepared, but not much work is actually done.

(If you're correct, I agree that this is probably a bug, though.)

It doesn't matter, you can put it just loosely in the script or in OnPluginInstall Callback. The result is unfortunately the same.

Seems like a bug. In fact the bug is in the core MFC libraries, since it seems that the library function GetPathName does not return a pathname during document serialization (which is where plugins are initially loaded).

However it knows the path of the document (naturally) as it is reading it in. I have put in an extra line that forces the document pathname to be the file pathname during serialization.

This appears to fix the bug. Applied in version 4.46.

As a workaround you may want to use GetPluginInfo (20) - the directory this particular plugin is installed in.

GetInfo(67) uses the information from GetInfo(54) so that would explain that behaviour.

Another workaround for the moment would be to use a timer, that waits a second and then loads the background. I think this behaviour is only during the initial world serialization.