An option along the lines of diff's --new-file for the various changeset displaying commands would be nice.  Not least so people can send regular unified diffs around based on work in their arch trees, using nothing but "tla what-changed --diffs" and "tla show-changest --diffs", i.e., no intermediate trees.

I can see this being triggered via a flag to arch_print_changeset, and then calling "diff -u --label=orig/path/within/tree/filename.c --label=mod/path/within/tree/filename.c /dev/null path/within/tree/filename.c" on each added file.  diff will neatly handle binary files (by printing "foo is binary" on stderr) and the result will be a shiny new patch.

Perhaps an option to exclude arch control files could be part of this, too, thought filterdiff makes it possibly to achieve this outside tla.

If no one pounces on this, I'll code it up in the next couple of days.