git format-patch --range-diff accepts non-quoted arguments (shouldn't it be?)

Hi,

I think it is rather odd that `git format-patch --range-diff` accepts 
<previous> argument without enclosed in quotes, since it is always 
multi-word (separated by space). E.g., below works:

     $ git format-patch <options> --range-diff=main..previous main..HEAD

but below returns nothing:

     $ git format-patch <options> --range-diff="main..previous main..HEAD"

Should the quoted <previous> argument to --range-diff be allowed, and 
forbid the unquoted counterpart?

-- 
An old man doll... just what I always wanted! - Clara