merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 16 insertions, 25 deletions

diff --git a/third_party/git/t/t5552-skipping-fetch-negotiator.sh b/third_party/git/t/t5552-skipping-fetch-negotiator.sh
index 8a14be51a1..156c704040 100755
--- a/third_party/git/t/t5552-skipping-fetch-negotiator.sh
+++ b/third_party/git/t/t5552-skipping-fetch-negotiator.sh
@@ -60,29 +60,6 @@ test_expect_success 'commits with no parents are sent regardless of skip distanc
 	have_not_sent c6 c4 c3
 '
 
-test_expect_success 'unknown fetch.negotiationAlgorithm values error out' '
-	rm -rf server client trace &&
-	git init server &&
-	test_commit -C server to_fetch &&
-
-	git init client &&
-	test_commit -C client on_client &&
-	git -C client checkout on_client &&
-
-	test_config -C client fetch.negotiationAlgorithm invalid &&
-	test_must_fail git -C client fetch "$(pwd)/server" 2>err &&
-	test_i18ngrep "unknown fetch negotiation algorithm" err &&
-
-	# Explicit "default" value
-	test_config -C client fetch.negotiationAlgorithm default &&
-	git -C client -c fetch.negotiationAlgorithm=default fetch "$(pwd)/server" &&
-
-	# Implementation detail: If there is nothing to fetch, we will not error out
-	test_config -C client fetch.negotiationAlgorithm invalid &&
-	git -C client fetch "$(pwd)/server" 2>err &&
-	test_i18ngrep ! "unknown fetch negotiation algorithm" err
-'
-
 test_expect_success 'when two skips collide, favor the larger one' '
 	rm -rf server client trace &&
 	git init server &&
@@ -130,7 +107,11 @@ test_expect_success 'use ref advertisement to filter out commits' '
 
 	# The ref advertisement itself is filtered when protocol v2 is used, so
 	# use v0.
-	GIT_TEST_PROTOCOL_VERSION= trace_fetch client origin to_fetch &&
+	(
+		GIT_TEST_PROTOCOL_VERSION=0 &&
+		export GIT_TEST_PROTOCOL_VERSION &&
+		trace_fetch client origin to_fetch
+	) &&
 	have_sent c5 c4^ c2side &&
 	have_not_sent c4 c4^^ c4^^^
 '
@@ -192,7 +173,17 @@ test_expect_success 'do not send "have" with ancestors of commits that server AC
 	test_commit -C server commit-on-b1 &&
 
 	test_config -C client fetch.negotiationalgorithm skipping &&
-	trace_fetch client "$(pwd)/server" to_fetch &&
+
+	# NEEDSWORK: The number of "have"s sent depends on whether the transport
+	# is stateful. If the overspecification of the result were reduced, this
+	# test could be used for both stateful and stateless transports.
+	(
+		# Force protocol v0, in which local transport is stateful (in
+		# protocol v2 it is stateless).
+		GIT_TEST_PROTOCOL_VERSION=0 &&
+		export GIT_TEST_PROTOCOL_VERSION &&
+		trace_fetch client "$(pwd)/server" to_fetch
+	) &&
 	grep "  fetch" trace &&
 
 	# fetch-pack sends 2 requests each containing 16 "have" lines before