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, 150 insertions, 0 deletions

diff --git a/third_party/git/t/t6400-merge-df.sh b/third_party/git/t/t6400-merge-df.sh
new file mode 100755
index 0000000000..f1b84617af
--- /dev/null
+++ b/third_party/git/t/t6400-merge-df.sh
@@ -0,0 +1,150 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Fredrik Kuivinen
+#
+
+test_description='Test merge with directory/file conflicts'
+. ./test-lib.sh
+
+test_expect_success 'prepare repository' '
+	echo Hello >init &&
+	git add init &&
+	git commit -m initial &&
+
+	git branch B &&
+	mkdir dir &&
+	echo foo >dir/foo &&
+	git add dir/foo &&
+	git commit -m "File: dir/foo" &&
+
+	git checkout B &&
+	echo file dir >dir &&
+	git add dir &&
+	git commit -m "File: dir"
+'
+
+test_expect_success 'Merge with d/f conflicts' '
+	test_expect_code 1 git merge -m "merge msg" master
+'
+
+test_expect_success 'F/D conflict' '
+	git reset --hard &&
+	git checkout master &&
+	rm .git/index &&
+
+	mkdir before &&
+	echo FILE >before/one &&
+	echo FILE >after &&
+	git add . &&
+	git commit -m first &&
+
+	rm -f after &&
+	git mv before after &&
+	git commit -m move &&
+
+	git checkout -b para HEAD^ &&
+	echo COMPLETELY ANOTHER FILE >another &&
+	git add . &&
+	git commit -m para &&
+
+	git merge master
+'
+
+test_expect_success 'setup modify/delete + directory/file conflict' '
+	git checkout --orphan modify &&
+	git rm -rf . &&
+	git clean -fdqx &&
+
+	printf "a\nb\nc\nd\ne\nf\ng\nh\n" >letters &&
+	git add letters &&
+	git commit -m initial &&
+
+	# Throw in letters.txt for sorting order fun
+	# ("letters.txt" sorts between "letters" and "letters/file")
+	echo i >>letters &&
+	echo "version 2" >letters.txt &&
+	git add letters letters.txt &&
+	git commit -m modified &&
+
+	git checkout -b delete HEAD^ &&
+	git rm letters &&
+	mkdir letters &&
+	>letters/file &&
+	echo "version 1" >letters.txt &&
+	git add letters letters.txt &&
+	git commit -m deleted
+'
+
+test_expect_success 'modify/delete + directory/file conflict' '
+	git checkout delete^0 &&
+	test_must_fail git merge modify &&
+
+	test 5 -eq $(git ls-files -s | wc -l) &&
+	test 4 -eq $(git ls-files -u | wc -l) &&
+	test 1 -eq $(git ls-files -o | wc -l) &&
+
+	test_path_is_file letters/file &&
+	test_path_is_file letters.txt &&
+	test_path_is_file letters~modify
+'
+
+test_expect_success 'modify/delete + directory/file conflict; other way' '
+	git reset --hard &&
+	git clean -f &&
+	git checkout modify^0 &&
+
+	test_must_fail git merge delete &&
+
+	test 5 -eq $(git ls-files -s | wc -l) &&
+	test 4 -eq $(git ls-files -u | wc -l) &&
+	test 1 -eq $(git ls-files -o | wc -l) &&
+
+	test_path_is_file letters/file &&
+	test_path_is_file letters.txt &&
+	test_path_is_file letters~HEAD
+'
+
+test_expect_success 'Simple merge in repo with interesting pathnames' '
+	# Simple lexicographic ordering of files and directories would be:
+	#     foo
+	#     foo/bar
+	#     foo/bar-2
+	#     foo/bar/baz
+	#     foo/bar-2/baz
+	# The fact that foo/bar-2 appears between foo/bar and foo/bar/baz
+	# can trip up some codepaths, and is the point of this test.
+	test_create_repo name-ordering &&
+	(
+		cd name-ordering &&
+
+		mkdir -p foo/bar &&
+		mkdir -p foo/bar-2 &&
+		>foo/bar/baz &&
+		>foo/bar-2/baz &&
+		git add . &&
+		git commit -m initial &&
+
+		git branch topic &&
+		git branch other &&
+
+		git checkout other &&
+		echo other >foo/bar-2/baz &&
+		git add -u &&
+		git commit -m other &&
+
+		git checkout topic &&
+		echo topic >foo/bar/baz &&
+		git add -u &&
+		git commit -m topic &&
+
+		git merge other &&
+		git ls-files -s >out &&
+		test_line_count = 2 out &&
+		git rev-parse :0:foo/bar/baz :0:foo/bar-2/baz >actual &&
+		git rev-parse HEAD~1:foo/bar/baz other:foo/bar-2/baz >expect &&
+		test_cmp expect actual
+	)
+
+'
+
+test_done