gitk feature requests: (1) "diff.orderFile" and (2) "--function-context"

Hello,

as of commit c1a63459ed73 ("gitk: Preserve window dimensions on exit when not using ttk themes", 2019-12-15), gitk seems to lack two features that I consider "killer" ones, for reviewing patches (including my own patches, of course):

- support for the "--function-context" ("-W") option,
- support for the "-O<orderfile>" (aka "diff.orderFile") setting.

These flags are in fact mentioned in the gitk source code, going back to historical commit ee66e089c1d4 ("gitk: Make updates go faster", 2008-05-09).

The options are stashed in vdflags($n), and then summarily ignored. A comment says, "These request or affect diff output, which we don't want", and I don't understand why; I would very much like them, please :)

Why I'm not proposing patches myself: my knowledge of Tcl/Tk is weaker than my knowledge of Perl. My knowledge of Perl is... well, let's change the topic. :) I have basically zero idea what "gitk" source does, for the most part.

Could someone please write gitk patches for honoring "diff.orderFile" and "--function-context"?

Accepting "--find-copies-harder" too would be the icing on the cake.

Thank you! Laszlo