Sorry for delayed response. I've been without Internet for more than a day.
It looks like I caused some, if not all, of the problem. When I undertook my experiment I created the folder that was referenced by the variable GIMP2_DIRECTORY whereas the comparable folder did not exist when doing the normal startup. However, if this folder is also removed for the portable case then the startup looks the same and the fairly large set of empty folders are created. Also the console messages look identical. Therefore, I’m guessing that what could be triggering the creation of these folders, previously missing on startup, is that GIMP fails to find the applicable folder. The one slight difference that remains is that in the portable case (i.e., using GIMP2_DIRECTORY rather than default) the sub-folder named “2.9” is not created. Guessing again about the logic makes me think that when default is used GIMP contemplates the possibility for multiple, possibly incompatible, versions of GIMP to be sharing this directory and so the one named “2.9” is created to preserve integrity in such a case. When the user overrides the default the idea is to put it where the user requested.
At this point the portable case looks good even though I must admit that not much usage of GIMP has occurred yet. Therefore, I’m very grateful for the assistance that Rich provided. I wouldn't have gotten this working otherwise.
This does lead to another question but I'm thinking that belongs in another post.
Just in case this matters to anyone else I’ve attached the script that I now have working. I hope it is commented well enough to explain what needs to be done to use it. Apparently this site won't allow attachments with the .js file extension therefore I've appended .txt which must be removed to use the script.
THANKS to RICH
It looks like I caused some, if not all, of the problem. When I undertook my experiment I created the folder that was referenced by the variable GIMP2_DIRECTORY whereas the comparable folder did not exist when doing the normal startup. However, if this folder is also removed for the portable case then the startup looks the same and the fairly large set of empty folders are created. Also the console messages look identical. Therefore, I’m guessing that what could be triggering the creation of these folders, previously missing on startup, is that GIMP fails to find the applicable folder. The one slight difference that remains is that in the portable case (i.e., using GIMP2_DIRECTORY rather than default) the sub-folder named “2.9” is not created. Guessing again about the logic makes me think that when default is used GIMP contemplates the possibility for multiple, possibly incompatible, versions of GIMP to be sharing this directory and so the one named “2.9” is created to preserve integrity in such a case. When the user overrides the default the idea is to put it where the user requested.
At this point the portable case looks good even though I must admit that not much usage of GIMP has occurred yet. Therefore, I’m very grateful for the assistance that Rich provided. I wouldn't have gotten this working otherwise.
This does lead to another question but I'm thinking that belongs in another post.
Just in case this matters to anyone else I’ve attached the script that I now have working. I hope it is commented well enough to explain what needs to be done to use it. Apparently this site won't allow attachments with the .js file extension therefore I've appended .txt which must be removed to use the script.
THANKS to RICH