How to keep the white space at end of line?

[alex]

By default editor trims trailing white space (spaces, tabs) when you save the file.

To disable this behaviour and keep contents as it is, you can unset flag Trim white space at the end of line, which can be found in Tools -> Options -> Fromatting -> Do on Save.

[Arthur]

is there a way to also substitute the tabs to space characters at save file time?

[Stefan]

is there a way to also substitute the tabs to space characters at save file time?

I think not "on save",  ... but while editing (see "Tools -> Options -> Formatting ")

[alex]

Hello Arthur,

checkong the code, I have found interesting thing...

It should work already, if you have TabsToSpaces set, as mentioned by Stefan.
So the option controls what should be done on editing and in addition, should convert tabs to spaces on save of document.

The same should also work if you have Tabs and Spaces mode set to Auto and initially in the content were not tabs (should be enough content for analysis).

Best regards,
Alex.