Re: [PATCH 5/7] fetch-pack: support fetching from a shallow repository

Nguyễn Thái Ngọc Duy  [off-list ref] writes:

Only server graft points that do not have corresponding SHA-1s in
local repo are added to the temp shallow file because we don't want to
accidentally cut the client history because the server's is
shorter. The client cutting can only happen when --depth is requested.

This "have corresponding SHA-1" is iffy from connectivity point of view,
isn't it?  That is,...

+	for (i = 0; i < extra->nr; i++) {
+		if (!remove_unused_grafts && has_sha1_file(extra->array[i]))

...shouldn't this require much more than "has_sha1_file()", like
"has it, and we have everything behind it with respect to the
shallow graft points we started with" or something?

Otherwise an isolated island that was left behind by an earlier
aborted commit walker fetch may mislead us to believe that we have
the complete history behind this commit object.