tree 22ad03c602452032557113d7a0d9622d2a54e9d2
parent e362fadcd03753471cf8e7fc91d6d721b7423b8f
author Jonathan Tan <jonathantanmy@google.com> 1573605260 -0800
committer Junio C Hamano <gitster@pobox.com> 1573613458 +0900

promisor-remote: remove fetch_if_missing=0

Commit 6462d5eb9a ("fetch: remove fetch_if_missing=0", 2019-11-08)
strove to remove the need for fetch_if_missing=0 from the fetching
mechanism, so it is plausible to attempt removing fetch_if_missing=0
from the lazy-fetching mechanism in promisor-remote as well.

But doing so reveals a bug - when the server does not send an object
pointed to by a tag object, an infinite loop occurs: Git attempts to
fetch the missing object, which causes a deferencing of all refs (for
negotiation), which causes a lazy fetch of that missing object, and so
on. This bug is because of unnecessary use of the fetch negotiator
during lazy fetching - it is not used after initialization, but it is
still initialized (which causes the dereferencing of all refs).

Thus, when the negotiator is not used during fetching, refrain from
initializing it. Then, remove fetch_if_missing from promisor-remote.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>