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

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

third_party/git/t/t5515-fetch-merge-logic.sh

@@ -8,18 +8,60 @@ test_description='Merge logic in fetch'
 
 # NEEDSWORK: If the overspecification of the expected result is reduced, we
 # might be able to run this test in all protocol versions.
-GIT_TEST_PROTOCOL_VERSION=
+GIT_TEST_PROTOCOL_VERSION=0
+export GIT_TEST_PROTOCOL_VERSION
 
 . ./test-lib.sh
 
-LF='
-'
+build_script () {
+	script="$1" &&
+	for i in one three_file master topic_2 one_tree three two two2 three2
+	do
+		echo "s/$(test_oid --hash=sha1 "$i")/$(test_oid "$i")/g" >>"$script"
+	done
+}
+
+convert_expected () {
+	file="$1" &&
+	script="$2" &&
+	sed -f "$script" "$file" >"$file.tmp" &&
+	mv "$file.tmp" "$file"
+}
 
 test_expect_success setup '
 	GIT_AUTHOR_DATE="2006-06-26 00:00:00 +0000" &&
 	GIT_COMMITTER_DATE="2006-06-26 00:00:00 +0000" &&
 	export GIT_AUTHOR_DATE GIT_COMMITTER_DATE &&
 
+	test_oid_cache <<-EOF &&
+	one sha1:8e32a6d901327a23ef831511badce7bf3bf46689
+	one sha256:8739546433ab1ac72ee93088dce611210effee072b2b586ceac6dde43ebec9ce
+
+	three_file sha1:0e3b14047d3ee365f4f2a1b673db059c3972589c
+	three_file sha256:bc4447d50c07497a8bfe6eef817f2364ecca9d471452e43b52756cc1a908bd32
+
+	master sha1:6c9dec2b923228c9ff994c6cfe4ae16c12408dc5
+	master sha256:8521c3072461fcfe8f32d67f95cc6e6b832a2db2fa29769ffc788bce85ebcd75
+
+	one_tree sha1:22feea448b023a2d864ef94b013735af34d238ba
+	one_tree sha256:6e4743f4ef2356b881dda5e91f5c7cdffe870faf350bf7b312f80a20935f5d83
+
+	three sha1:c61a82b60967180544e3c19f819ddbd0c9f89899
+	three sha256:0cc6d1eda617ded715170786e31ba4e2d0185404ec5a3508dd0d73b324860c6a
+
+	two sha1:525b7fb068d59950d185a8779dc957c77eed73ba
+	two sha256:3b21de3440cd38c2a9e9b464adb923f7054949ed4c918e1a0ac4c95cd52774db
+
+	topic_2 sha1:754b754407bf032e9a2f9d5a9ad05ca79a6b228f
+	topic_2 sha256:6c7abaea8a6d8ef4d89877e68462758dc6774690fbbbb0e6d7dd57415c9abde0
+
+	two2 sha1:6134ee8f857693b96ff1cc98d3e2fd62b199e5a8
+	two2 sha256:87a2d3ee29c83a3dc7afd41c0606b11f67603120b910a7be7840accdc18344d4
+
+	three2 sha1:0567da4d5edd2ff4bb292a465ba9e64dcad9536b
+	three2 sha256:cceb3e8eca364fa9a0a39a1efbebecacc664af86cbbd8070571f5faeb5f0e8c3
+	EOF
+
 	echo >file original &&
 	git add file &&
 	git commit -a -m One &&
@@ -89,7 +131,8 @@ test_expect_success setup '
 		git config branch.br-$remote-octopus.remote $remote &&
 		git config branch.br-$remote-octopus.merge refs/heads/one &&
 		git config --add branch.br-$remote-octopus.merge two
-	done
+	done &&
+	build_script sed_script
 '
 
 # Merge logic depends on branch properties and Pull: or .fetch lines
@@ -140,6 +183,10 @@ do
 	actual_r="$pfx-refs.$test"
 
 	test_expect_success "$cmd" '
+		cp "$expect_f" expect_f &&
+		convert_expected expect_f sed_script &&
+		cp "$expect_r" expect_r &&
+		convert_expected expect_r sed_script &&
 		{
 			echo "# $cmd"
 			set x $cmd; shift
@@ -155,18 +202,18 @@ do
 			cat .git/FETCH_HEAD
 		} >"$actual_f" &&
 		git show-ref >"$actual_r" &&
-		if test -f "$expect_f"
+		if test -f "expect_f"
 		then
-			test_cmp "$expect_f" "$actual_f" &&
+			test_cmp "expect_f" "$actual_f" &&
 			rm -f "$actual_f"
 		else
 			# this is to help developing new tests.
 			cp "$actual_f" "$expect_f"
 			false
 		fi &&
-		if test -f "$expect_r"
+		if test -f "expect_r"
 		then
-			test_cmp "$expect_r" "$actual_r" &&
+			test_cmp "expect_r" "$actual_r" &&
 			rm -f "$actual_r"
 		else
 			# this is to help developing new tests.