Where and how is defined "default folder" for Open a/o Save

[LaurentGrenet]

I would like to understand how (and where...) is defined the default folder for dialogs opened with Ctrl+O (to open a new image) or Ctrl+S (to save current image) ????

I would imagine that it should be last opened folder with JpegView (and then this "default" folder is "auto-updated", but nope !

If I launch JpegView without any image as parameter, the proposed folder is ALWAYS the same, and remains for save even if I finally load an image from another folder. This folder is one of the folders in my Picture folder, but why this one and not another one ? No idea !

On the other hand, if I launch JpegView with one image selected as parameter, the proposed folder to open an new one (Ctrl+O) or save the current one (Ctrl+S) if the folder in which resides the image currently displayed (this is OK) BUT ONLY PROVIDED it is NOT the default temp folder, nor any of its subfolders ! If current image is stored in temp folder or one of its subfolders, JpgView propose to open or save from the same folder (below My Pictures) mentioned above....

I'm running rev 1.3.46 on W10 Pro, and the shortcut to launch JpegView mentions as "default folder" (start in...) the folder where resides the exe itself. Why isn't it set as default folder for Open and Save ?