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, 77 insertions, 0 deletions

diff --git a/third_party/git/t/t3431-rebase-fork-point.sh b/third_party/git/t/t3431-rebase-fork-point.sh
new file mode 100755
index 000000000000..172562789e47
--- /dev/null
+++ b/third_party/git/t/t3431-rebase-fork-point.sh
@@ -0,0 +1,77 @@
+#!/bin/sh
+#
+# Copyright (c) 2019 Denton Liu
+#
+
+test_description='git rebase --fork-point test'
+
+. ./test-lib.sh
+
+# A---B---D---E    (master)
+#      \
+#       C*---F---G (side)
+#
+# C was formerly part of master but master was rewound to remove C
+#
+test_expect_success setup '
+	test_commit A &&
+	test_commit B &&
+	test_commit C &&
+	git branch -t side &&
+	git reset --hard HEAD^ &&
+	test_commit D &&
+	test_commit E &&
+	git checkout side &&
+	test_commit F &&
+	test_commit G
+'
+
+test_rebase () {
+	expected="$1" &&
+	shift &&
+	test_expect_success "git rebase $*" "
+		git checkout master &&
+		git reset --hard E &&
+		git checkout side &&
+		git reset --hard G &&
+		git rebase $* &&
+		test_write_lines $expected >expect &&
+		git log --pretty=%s >actual &&
+		test_cmp expect actual
+	"
+}
+
+test_rebase 'G F E D B A'
+test_rebase 'G F D B A' --onto D
+test_rebase 'G F B A' --keep-base
+test_rebase 'G F C E D B A' --no-fork-point
+test_rebase 'G F C D B A' --no-fork-point --onto D
+test_rebase 'G F C B A' --no-fork-point --keep-base
+
+test_rebase 'G F E D B A' --fork-point refs/heads/master
+test_rebase 'G F E D B A' --fork-point master
+
+test_rebase 'G F D B A' --fork-point --onto D refs/heads/master
+test_rebase 'G F D B A' --fork-point --onto D master
+
+test_rebase 'G F B A' --fork-point --keep-base refs/heads/master
+test_rebase 'G F B A' --fork-point --keep-base master
+
+test_rebase 'G F C E D B A' refs/heads/master
+test_rebase 'G F C E D B A' master
+
+test_rebase 'G F C D B A' --onto D refs/heads/master
+test_rebase 'G F C D B A' --onto D master
+
+test_rebase 'G F C B A' --keep-base refs/heads/master
+test_rebase 'G F C B A' --keep-base master
+
+test_expect_success 'git rebase --fork-point with ambigous refname' '
+	git checkout master &&
+	git checkout -b one &&
+	git checkout side &&
+	git tag one &&
+	test_must_fail git rebase --fork-point --onto D one
+'
+
+test_done