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/t7102-reset.sh

@@ -37,17 +37,23 @@ test_expect_success 'creating initial files and commits' '
 
 	echo "2nd line 1st file" >>first &&
 	git commit -a -m "modify 1st file" &&
+	head5p2=$(git rev-parse --verify HEAD) &&
+	head5p2f=$(git rev-parse --short HEAD:first) &&
 
 	git rm first &&
 	git mv second secondfile &&
 	git commit -a -m "remove 1st and rename 2nd" &&
+	head5p1=$(git rev-parse --verify HEAD) &&
+	head5p1s=$(git rev-parse --short HEAD:secondfile) &&
 
 	echo "1st line 2nd file" >secondfile &&
 	echo "2nd line 2nd file" >>secondfile &&
 	# "git commit -m" would break MinGW, as Windows refuse to pass
 	# $test_encoding encoded parameter to git.
 	commit_msg $test_encoding | git -c "i18n.commitEncoding=$test_encoding" commit -a -F - &&
-	head5=$(git rev-parse --verify HEAD)
+	head5=$(git rev-parse --verify HEAD) &&
+	head5s=$(git rev-parse --short HEAD:secondfile) &&
+	head5sl=$(git rev-parse HEAD:secondfile)
 '
 # git log --pretty=oneline # to see those SHA1 involved
 
@@ -94,7 +100,7 @@ test_expect_success 'giving a non existing revision should fail' '
 
 test_expect_success 'reset --soft with unmerged index should fail' '
 	touch .git/MERGE_HEAD &&
-	echo "100644 44c5b5884550c17758737edcced463447b91d42b 1	un" |
+	echo "100644 $head5sl 1	un" |
 		git update-index --index-info &&
 	test_must_fail git reset --soft HEAD &&
 	rm .git/MERGE_HEAD &&
@@ -192,7 +198,7 @@ test_expect_success \
 >.diff_expect
 cat >.cached_expect <<EOF
 diff --git a/secondfile b/secondfile
-index 1bbba79..44c5b58 100644
+index $head5p1s..$head5s 100644
 --- a/secondfile
 +++ b/secondfile
 @@ -1 +1,2 @@
@@ -207,7 +213,7 @@ secondfile:
 EOF
 test_expect_success '--soft reset only should show changes in diff --cached' '
 	git reset --soft HEAD^ &&
-	check_changes d1a4bc3abce4829628ae2dcb0d60ef3d1a78b1c4 &&
+	check_changes $head5p1 &&
 	test "$(git rev-parse ORIG_HEAD)" = \
 			$head5
 '
@@ -242,7 +248,7 @@ EOF
 test_expect_success \
 	'--hard reset should change the files and undo commits permanently' '
 	git reset --hard HEAD~2 &&
-	check_changes ddaefe00f1da16864591c61fdc7adb5d7cd6b74e &&
+	check_changes $head5p2 &&
 	test "$(git rev-parse ORIG_HEAD)" = \
 			$head4
 '
@@ -251,7 +257,7 @@ test_expect_success \
 cat >.cached_expect <<EOF
 diff --git a/first b/first
 deleted file mode 100644
-index 8206c22..0000000
+index $head5p2f..0000000
 --- a/first
 +++ /dev/null
 @@ -1,2 +0,0 @@
@@ -259,14 +265,14 @@ index 8206c22..0000000
 -2nd line 1st file
 diff --git a/second b/second
 deleted file mode 100644
-index 1bbba79..0000000
+index $head5p1s..0000000
 --- a/second
 +++ /dev/null
 @@ -1 +0,0 @@
 -2nd file
 diff --git a/secondfile b/secondfile
 new file mode 100644
-index 0000000..44c5b58
+index 0000000..$head5s
 --- /dev/null
 +++ b/secondfile
 @@ -0,0 +1,2 @@
@@ -286,13 +292,13 @@ test_expect_success \
 	echo "1st line 2nd file" >secondfile &&
 	echo "2nd line 2nd file" >>secondfile &&
 	git add secondfile &&
-	check_changes ddaefe00f1da16864591c61fdc7adb5d7cd6b74e
+	check_changes $head5p2
 '
 
 cat >.diff_expect <<EOF
 diff --git a/first b/first
 deleted file mode 100644
-index 8206c22..0000000
+index $head5p2f..0000000
 --- a/first
 +++ /dev/null
 @@ -1,2 +0,0 @@
@@ -300,7 +306,7 @@ index 8206c22..0000000
 -2nd line 1st file
 diff --git a/second b/second
 deleted file mode 100644
-index 1bbba79..0000000
+index $head5p1s..0000000
 --- a/second
 +++ /dev/null
 @@ -1 +0,0 @@
@@ -314,9 +320,8 @@ secondfile:
 EOF
 test_expect_success '--mixed reset to HEAD should unadd the files' '
 	git reset &&
-	check_changes ddaefe00f1da16864591c61fdc7adb5d7cd6b74e &&
-	test "$(git rev-parse ORIG_HEAD)" = \
-			ddaefe00f1da16864591c61fdc7adb5d7cd6b74e
+	check_changes $head5p2 &&
+	test "$(git rev-parse ORIG_HEAD)" = $head5p2
 '
 
 >.diff_expect
@@ -328,7 +333,7 @@ secondfile:
 EOF
 test_expect_success 'redoing the last two commits should succeed' '
 	git add secondfile &&
-	git reset --hard ddaefe00f1da16864591c61fdc7adb5d7cd6b74e &&
+	git reset --hard $head5p2 &&
 
 	git rm first &&
 	git mv second secondfile &&
@@ -389,47 +394,55 @@ test_expect_success \
 	check_changes $head5
 '
 
-cat > expect << EOF
-diff --git a/file1 b/file1
-index d00491f..7ed6ff8 100644
---- a/file1
-+++ b/file1
-@@ -1 +1 @@
--1
-+5
-diff --git a/file2 b/file2
-deleted file mode 100644
-index 0cfbf08..0000000
---- a/file2
-+++ /dev/null
-@@ -1 +0,0 @@
--2
-EOF
-cat > cached_expect << EOF
-diff --git a/file4 b/file4
-new file mode 100644
-index 0000000..b8626c4
---- /dev/null
-+++ b/file4
-@@ -0,0 +1 @@
-+4
-EOF
 test_expect_success 'test --mixed <paths>' '
 	echo 1 > file1 &&
 	echo 2 > file2 &&
 	git add file1 file2 &&
 	test_tick &&
 	git commit -m files &&
+	before1=$(git rev-parse --short HEAD:file1) &&
+	before2=$(git rev-parse --short HEAD:file2) &&
 	git rm file2 &&
 	echo 3 > file3 &&
 	echo 4 > file4 &&
 	echo 5 > file1 &&
+	after1=$(git rev-parse --short $(git hash-object file1)) &&
+	after4=$(git rev-parse --short $(git hash-object file4)) &&
 	git add file1 file3 file4 &&
 	git reset HEAD -- file1 file2 file3 &&
 	test_must_fail git diff --quiet &&
 	git diff > output &&
+
+	cat > expect <<-EOF &&
+	diff --git a/file1 b/file1
+	index $before1..$after1 100644
+	--- a/file1
+	+++ b/file1
+	@@ -1 +1 @@
+	-1
+	+5
+	diff --git a/file2 b/file2
+	deleted file mode 100644
+	index $before2..0000000
+	--- a/file2
+	+++ /dev/null
+	@@ -1 +0,0 @@
+	-2
+	EOF
+
 	test_cmp expect output &&
 	git diff --cached > output &&
+
+	cat > cached_expect <<-EOF &&
+	diff --git a/file4 b/file4
+	new file mode 100644
+	index 0000000..$after4
+	--- /dev/null
+	+++ b/file4
+	@@ -0,0 +1 @@
+	+4
+	EOF
+
 	test_cmp cached_expect output
 '