Re: [PATCH v2 1/3] diff: have submodule_format logic avoid additional diff headers

"Elijah Newren via GitGitGadget" [off-list ref] writes:


As there is no guarantee that we'd never add another hack to use a
different kind of "phoney" filepair to diff_queue for another
purpose, either the name of the helper function, or a comment in
front of it, should say something that is sufficient to help readers
understand ...

+static int diff_filepair_is_phoney(struct diff_filespec *one,
+				   struct diff_filespec *two)
+{
+	return !DIFF_FILE_VALID(one) && !DIFF_FILE_VALID(two);
+}
...
-	if (!DIFF_FILE_VALID(one) && !DIFF_FILE_VALID(two)) {
+	if (diff_filepair_is_phoney(one, two)) {
 		/*
 		 * We should only reach this point for pairs from
 		 * create_filepairs_for_header_only_notifications().  For

... some of what this comment said, i.e. the pair that was added by
create_filepairs_for_header_only_notifications() is what the helper
detects. 

Other than that, the whole series looks good.