Saving with only a filename (from Python) wasn't being prevented, while it would successfully write the file to the working-directory, path remapping and setting relative paths wouldn't work afterwards as `Main.filepath` would have no directory component.
Disallow this since it's a corner case which only ever occurs when path names without any directories are used from Python, the overhead of expanding the working-directory for all data saving operations isn't worthwhile.
The following changes have been made:
- bpy.ops.wm.save_mainfile() without a filepath argument fails & reports and error when the file hasn't been saved.
Previously it would write to "untitled.blend" and set the `G.main->filepath` to this as well.
- bpy.ops.wm.save_mainfile(filepath="untitled.blend") fails & reports and error as the filename has no directory component.
- `BLI_path_is_abs_from_cwd` was added to check if the path would attempt to expand to the CWD.
Full Hash: 8dbd406ea0f495b3d404a7433a32b4781953e55a Parent Commit: 15c3617 Lines Changed: +49, -16