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, 296 insertions, 87 deletions

diff --git a/third_party/git/t/t9300-fast-import.sh b/third_party/git/t/t9300-fast-import.sh
index 141b7fa35e..308c1ef42c 100755
--- a/third_party/git/t/t9300-fast-import.sh
+++ b/third_party/git/t/t9300-fast-import.sh
@@ -85,6 +85,36 @@ test_expect_success 'A: create pack from stdin' '
 	An annotated tag that annotates a blob.
 	EOF
 
+	tag to-be-deleted
+	from :3
+	data <<EOF
+	Another annotated tag that annotates a blob.
+	EOF
+
+	reset refs/tags/to-be-deleted
+	from $ZERO_OID
+
+	tag nested
+	mark :6
+	from :4
+	data <<EOF
+	Tag of our lovely commit
+	EOF
+
+	reset refs/tags/nested
+	from $ZERO_OID
+
+	tag nested
+	mark :7
+	from :6
+	data <<EOF
+	Tag of tag of our lovely commit
+	EOF
+
+	alias
+	mark :8
+	to :5
+
 	INPUT_END
 	git fast-import --export-marks=marks.out <input &&
 	git whatchanged master
@@ -157,12 +187,19 @@ test_expect_success 'A: verify tag/series-A-blob' '
 	test_cmp expect actual
 '
 
+test_expect_success 'A: verify tag deletion is successful' '
+	test_must_fail git rev-parse --verify refs/tags/to-be-deleted
+'
+
 test_expect_success 'A: verify marks output' '
 	cat >expect <<-EOF &&
 	:2 $(git rev-parse --verify master:file2)
 	:3 $(git rev-parse --verify master:file3)
 	:4 $(git rev-parse --verify master:file4)
 	:5 $(git rev-parse --verify master^0)
+	:6 $(git cat-file tag nested | grep object | cut -d" " -f 2)
+	:7 $(git rev-parse --verify nested)
+	:8 $(git rev-parse --verify master^0)
 	EOF
 	test_cmp expect marks.out
 '
@@ -247,8 +284,9 @@ test_expect_success 'A: verify pack' '
 '
 
 test_expect_success 'A: verify diff' '
+	copy=$(git rev-parse --verify master:file2) &&
 	cat >expect <<-EOF &&
-	:000000 100755 0000000000000000000000000000000000000000 7123f7f44e39be127c5eb701e5968176ee9d78b1 A	copy-of-file2
+	:000000 100755 $ZERO_OID $copy A	copy-of-file2
 	EOF
 	git diff-tree -M -r master verify--import-marks >actual &&
 	compare_diff_raw expect actual &&
@@ -327,7 +365,7 @@ test_expect_success 'B: fail on invalid blob sha1' '
 	COMMIT
 
 	from refs/heads/master
-	M 755 0000000000000000000000000000000000000001 zero1
+	M 755 $(echo $ZERO_OID | sed -e "s/0$/1/") zero1
 
 	INPUT_END
 
@@ -373,6 +411,34 @@ test_expect_success 'B: accept empty committer' '
 	test -z "$out"
 '
 
+test_expect_success 'B: reject invalid timezone' '
+	cat >input <<-INPUT_END &&
+	commit refs/heads/invalid-timezone
+	committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1234567890 +051800
+	data <<COMMIT
+	empty commit
+	COMMIT
+	INPUT_END
+
+	test_when_finished "git update-ref -d refs/heads/invalid-timezone" &&
+	test_must_fail git fast-import <input
+'
+
+test_expect_success 'B: accept invalid timezone with raw-permissive' '
+	cat >input <<-INPUT_END &&
+	commit refs/heads/invalid-timezone
+	committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1234567890 +051800
+	data <<COMMIT
+	empty commit
+	COMMIT
+	INPUT_END
+
+	git init invalid-timezone &&
+	git -C invalid-timezone fast-import --date-format=raw-permissive <input &&
+	git -C invalid-timezone cat-file -p invalid-timezone >out &&
+	grep "1234567890 [+]051800" out
+'
+
 test_expect_success 'B: accept and fixup committer with no name' '
 	cat >input <<-INPUT_END &&
 	commit refs/heads/empty-committer-2
@@ -463,6 +529,7 @@ test_expect_success 'B: fail on invalid committer (5)' '
 test_expect_success 'C: incremental import create pack from stdin' '
 	newf=$(echo hi newf | git hash-object -w --stdin) &&
 	oldf=$(git rev-parse --verify master:file2) &&
+	thrf=$(git rev-parse --verify master:file3) &&
 	test_tick &&
 	cat >input <<-INPUT_END &&
 	commit refs/heads/branch
@@ -505,10 +572,11 @@ test_expect_success 'C: verify commit' '
 '
 
 test_expect_success 'C: validate rename result' '
+	zero=$ZERO_OID &&
 	cat >expect <<-EOF &&
-	:000000 100755 0000000000000000000000000000000000000000 f1fb5da718392694d0076d677d6d0e364c79b0bc A	file2/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 R100	file2	file2/oldf
-	:100644 000000 0d92e9f3374ae2947c23aa477cbc68ce598135f1 0000000000000000000000000000000000000000 D	file3
+	:000000 100755 $zero $newf A	file2/newf
+	:100644 100644 $oldf $oldf R100	file2	file2/oldf
+	:100644 000000 $thrf $zero D	file3
 	EOF
 	git diff-tree -M -r master branch >actual &&
 	compare_diff_raw expect actual
@@ -549,9 +617,11 @@ test_expect_success 'D: verify pack' '
 '
 
 test_expect_success 'D: validate new files added' '
+	f5id=$(echo "$file5_data" | git hash-object --stdin) &&
+	f6id=$(echo "$file6_data" | git hash-object --stdin) &&
 	cat >expect <<-EOF &&
-	:000000 100755 0000000000000000000000000000000000000000 e74b7d465e52746be2b4bae983670711e6e66657 A	newdir/exec.sh
-	:000000 100644 0000000000000000000000000000000000000000 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 A	newdir/interesting
+	:000000 100755 $ZERO_OID $f6id A	newdir/exec.sh
+	:000000 100644 $ZERO_OID $f5id A	newdir/interesting
 	EOF
 	git diff-tree -M -r branch^ branch >actual &&
 	compare_diff_raw expect actual
@@ -714,12 +784,13 @@ test_expect_success 'H: verify pack' '
 '
 
 test_expect_success 'H: validate old files removed, new files added' '
+	f4id=$(git rev-parse HEAD:file4) &&
 	cat >expect <<-EOF &&
-	:100755 000000 f1fb5da718392694d0076d677d6d0e364c79b0bc 0000000000000000000000000000000000000000 D	file2/newf
-	:100644 000000 7123f7f44e39be127c5eb701e5968176ee9d78b1 0000000000000000000000000000000000000000 D	file2/oldf
-	:100755 000000 85df50785d62d3b05ab03d9cbf7e4a0b49449730 0000000000000000000000000000000000000000 D	file4
-	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 R100	newdir/interesting	h/e/l/lo
-	:100755 000000 e74b7d465e52746be2b4bae983670711e6e66657 0000000000000000000000000000000000000000 D	newdir/exec.sh
+	:100755 000000 $newf $zero D	file2/newf
+	:100644 000000 $oldf $zero D	file2/oldf
+	:100755 000000 $f4id $zero D	file4
+	:100644 100644 $f5id $f5id R100	newdir/interesting	h/e/l/lo
+	:100755 000000 $f6id $zero D	newdir/exec.sh
 	EOF
 	git diff-tree -M -r H^ H >actual &&
 	compare_diff_raw expect actual
@@ -870,14 +941,15 @@ test_expect_success 'L: verify internal tree sorting' '
 	INPUT_END
 
 	cat >expect <<-EXPECT_END &&
-	:100644 100644 4268632... 55d3a52... M	b.
-	:040000 040000 0ae5cac... 443c768... M	b
-	:100644 100644 4268632... 55d3a52... M	ba
+	:100644 100644 M	b.
+	:040000 040000 M	b
+	:100644 100644 M	ba
 	EXPECT_END
 
 	git fast-import <input &&
 	GIT_PRINT_SHA1_ELLIPSIS="yes" git diff-tree --abbrev --raw L^ L >output &&
-	test_cmp expect output
+	cut -d" " -f1,2,5 output >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'L: nested tree copy does not corrupt deltas' '
@@ -939,7 +1011,7 @@ test_expect_success 'M: rename file in same subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc R100	file2/newf	file2/n.e.w.f
+	:100755 100755 $newf $newf R100	file2/newf	file2/n.e.w.f
 	EOF
 	git fast-import <input &&
 	git diff-tree -M -r M1^ M1 >actual &&
@@ -960,7 +1032,7 @@ test_expect_success 'M: rename file to new subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc R100	file2/newf	i/am/new/to/you
+	:100755 100755 $newf $newf R100	file2/newf	i/am/new/to/you
 	EOF
 	git fast-import <input &&
 	git diff-tree -M -r M2^ M2 >actual &&
@@ -981,7 +1053,7 @@ test_expect_success 'M: rename subdirectory to new subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc R100	i/am/new/to/you	other/sub/am/new/to/you
+	:100755 100755 $newf $newf R100	i/am/new/to/you	other/sub/am/new/to/you
 	EOF
 	git fast-import <input &&
 	git diff-tree -M -r M3^ M3 >actual &&
@@ -1002,15 +1074,14 @@ test_expect_success 'M: rename root to subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 R100	file2/oldf	sub/file2/oldf
-	:100755 100755 85df50785d62d3b05ab03d9cbf7e4a0b49449730 85df50785d62d3b05ab03d9cbf7e4a0b49449730 R100	file4	sub/file4
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc R100	i/am/new/to/you	sub/i/am/new/to/you
-	:100755 100755 e74b7d465e52746be2b4bae983670711e6e66657 e74b7d465e52746be2b4bae983670711e6e66657 R100	newdir/exec.sh	sub/newdir/exec.sh
-	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 R100	newdir/interesting	sub/newdir/interesting
+	:100644 100644 $oldf $oldf R100	file2/oldf	sub/file2/oldf
+	:100755 100755 $f4id $f4id R100	file4	sub/file4
+	:100755 100755 $newf $newf R100	i/am/new/to/you	sub/i/am/new/to/you
+	:100755 100755 $f6id $f6id R100	newdir/exec.sh	sub/newdir/exec.sh
+	:100644 100644 $f5id $f5id R100	newdir/interesting	sub/newdir/interesting
 	EOF
 	git fast-import <input &&
 	git diff-tree -M -r M4^ M4 >actual &&
-	cat actual &&
 	compare_diff_raw expect actual
 '
 
@@ -1033,7 +1104,7 @@ test_expect_success 'N: copy file in same subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	file2/n.e.w.f
+	:100755 100755 $newf $newf C100	file2/newf	file2/n.e.w.f
 	EOF
 	git fast-import <input &&
 	git diff-tree -C --find-copies-harder -r N1^ N1 >actual &&
@@ -1065,9 +1136,9 @@ test_expect_success 'N: copy then modify subdirectory' '
 	INPUT_END
 
 	cat >expect <<-EOF &&
-	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 C100	newdir/interesting	file3/file5
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	file3/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	file3/oldf
+	:100644 100644 $f5id $f5id C100	newdir/interesting	file3/file5
+	:100755 100755 $newf $newf C100	file2/newf	file3/newf
+	:100644 100644 $oldf $oldf C100	file2/oldf	file3/oldf
 	EOF
 	git fast-import <input &&
 	git diff-tree -C --find-copies-harder -r N2^^ N2 >actual &&
@@ -1098,9 +1169,9 @@ test_expect_success 'N: copy dirty subdirectory' '
 '
 
 test_expect_success 'N: copy directory by id' '
-	cat >expect <<-\EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	file3/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	file3/oldf
+	cat >expect <<-EOF &&
+	:100755 100755 $newf $newf C100	file2/newf	file3/newf
+	:100644 100644 $oldf $oldf C100	file2/oldf	file3/oldf
 	EOF
 	subdir=$(git rev-parse refs/heads/branch^0:file2) &&
 	cat >input <<-INPUT_END &&
@@ -1119,9 +1190,9 @@ test_expect_success 'N: copy directory by id' '
 '
 
 test_expect_success PIPE 'N: read and copy directory' '
-	cat >expect <<-\EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	file3/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	file3/oldf
+	cat >expect <<-EOF &&
+	:100755 100755 $newf $newf C100	file2/newf	file3/newf
+	:100644 100644 $oldf $oldf C100	file2/oldf	file3/oldf
 	EOF
 	git update-ref -d refs/heads/N4 &&
 	rm -f backflow &&
@@ -1190,9 +1261,9 @@ test_expect_success PIPE 'N: empty directory reads as missing' '
 '
 
 test_expect_success 'N: copy root directory by tree hash' '
-	cat >expect <<-\EOF &&
-	:100755 000000 f1fb5da718392694d0076d677d6d0e364c79b0bc 0000000000000000000000000000000000000000 D	file3/newf
-	:100644 000000 7123f7f44e39be127c5eb701e5968176ee9d78b1 0000000000000000000000000000000000000000 D	file3/oldf
+	cat >expect <<-EOF &&
+	:100755 000000 $newf $zero D	file3/newf
+	:100644 000000 $oldf $zero D	file3/oldf
 	EOF
 	root=$(git rev-parse refs/heads/branch^0^{tree}) &&
 	cat >input <<-INPUT_END &&
@@ -1211,12 +1282,12 @@ test_expect_success 'N: copy root directory by tree hash' '
 '
 
 test_expect_success 'N: copy root by path' '
-	cat >expect <<-\EOF &&
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	oldroot/file2/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	oldroot/file2/oldf
-	:100755 100755 85df50785d62d3b05ab03d9cbf7e4a0b49449730 85df50785d62d3b05ab03d9cbf7e4a0b49449730 C100	file4	oldroot/file4
-	:100755 100755 e74b7d465e52746be2b4bae983670711e6e66657 e74b7d465e52746be2b4bae983670711e6e66657 C100	newdir/exec.sh	oldroot/newdir/exec.sh
-	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 C100	newdir/interesting	oldroot/newdir/interesting
+	cat >expect <<-EOF &&
+	:100755 100755 $newf $newf C100	file2/newf	oldroot/file2/newf
+	:100644 100644 $oldf $oldf C100	file2/oldf	oldroot/file2/oldf
+	:100755 100755 $f4id $f4id C100	file4	oldroot/file4
+	:100755 100755 $f6id $f6id C100	newdir/exec.sh	oldroot/newdir/exec.sh
+	:100644 100644 $f5id $f5id C100	newdir/interesting	oldroot/newdir/interesting
 	EOF
 	cat >input <<-INPUT_END &&
 	commit refs/heads/N-copy-root-path
@@ -1276,10 +1347,10 @@ test_expect_success 'N: delete directory by copying' '
 '
 
 test_expect_success 'N: modify copied tree' '
-	cat >expect <<-\EOF &&
-	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 C100	newdir/interesting	file3/file5
-	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	file3/newf
-	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	file3/oldf
+	cat >expect <<-EOF &&
+	:100644 100644 $f5id $f5id C100	newdir/interesting	file3/file5
+	:100755 100755 $newf $newf C100	file2/newf	file3/newf
+	:100644 100644 $oldf $oldf C100	file2/oldf	file3/oldf
 	EOF
 	subdir=$(git rev-parse refs/heads/branch^0:file2) &&
 	cat >input <<-INPUT_END &&
@@ -2106,12 +2177,27 @@ test_expect_success 'R: abort on receiving feature after data command' '
 	test_must_fail git fast-import <input
 '
 
+test_expect_success 'R: import-marks features forbidden by default' '
+	>git.marks &&
+	echo "feature import-marks=git.marks" >input &&
+	test_must_fail git fast-import <input &&
+	echo "feature import-marks-if-exists=git.marks" >input &&
+	test_must_fail git fast-import <input
+'
+
 test_expect_success 'R: only one import-marks feature allowed per stream' '
+	>git.marks &&
+	>git2.marks &&
 	cat >input <<-EOF &&
 	feature import-marks=git.marks
 	feature import-marks=git2.marks
 	EOF
 
+	test_must_fail git fast-import --allow-unsafe-features <input
+'
+
+test_expect_success 'R: export-marks feature forbidden by default' '
+	echo "feature export-marks=git.marks" >input &&
 	test_must_fail git fast-import <input
 '
 
@@ -2125,19 +2211,29 @@ test_expect_success 'R: export-marks feature results in a marks file being creat
 
 	EOF
 
-	cat input | git fast-import &&
+	git fast-import --allow-unsafe-features <input &&
 	grep :1 git.marks
 '
 
 test_expect_success 'R: export-marks options can be overridden by commandline options' '
-	cat input | git fast-import --export-marks=other.marks &&
-	grep :1 other.marks
+	cat >input <<-\EOF &&
+	feature export-marks=feature-sub/git.marks
+	blob
+	mark :1
+	data 3
+	hi
+
+	EOF
+	git fast-import --allow-unsafe-features \
+			--export-marks=cmdline-sub/other.marks <input &&
+	grep :1 cmdline-sub/other.marks &&
+	test_path_is_missing feature-sub
 '
 
 test_expect_success 'R: catch typo in marks file name' '
 	test_must_fail git fast-import --import-marks=nonexistent.marks </dev/null &&
 	echo "feature import-marks=nonexistent.marks" |
-	test_must_fail git fast-import
+	test_must_fail git fast-import --allow-unsafe-features
 '
 
 test_expect_success 'R: import and output marks can be the same file' '
@@ -2192,7 +2288,8 @@ test_expect_success 'R: --import-marks-if-exists' '
 test_expect_success 'R: feature import-marks-if-exists' '
 	rm -f io.marks &&
 
-	git fast-import --export-marks=io.marks <<-\EOF &&
+	git fast-import --export-marks=io.marks \
+			--allow-unsafe-features <<-\EOF &&
 	feature import-marks-if-exists=not_io.marks
 	EOF
 	test_must_be_empty io.marks &&
@@ -2203,7 +2300,8 @@ test_expect_success 'R: feature import-marks-if-exists' '
 	echo ":1 $blob" >expect &&
 	echo ":2 $blob" >>expect &&
 
-	git fast-import --export-marks=io.marks <<-\EOF &&
+	git fast-import --export-marks=io.marks \
+			--allow-unsafe-features <<-\EOF &&
 	feature import-marks-if-exists=io.marks
 	blob
 	mark :2
@@ -2216,7 +2314,8 @@ test_expect_success 'R: feature import-marks-if-exists' '
 	echo ":3 $blob" >>expect &&
 
 	git fast-import --import-marks=io.marks \
-			--export-marks=io.marks <<-\EOF &&
+			--export-marks=io.marks \
+			--allow-unsafe-features <<-\EOF &&
 	feature import-marks-if-exists=not_io.marks
 	blob
 	mark :3
@@ -2227,7 +2326,8 @@ test_expect_success 'R: feature import-marks-if-exists' '
 	test_cmp expect io.marks &&
 
 	git fast-import --import-marks-if-exists=not_io.marks \
-			--export-marks=io.marks <<-\EOF &&
+			--export-marks=io.marks \
+			--allow-unsafe-features <<-\EOF &&
 	feature import-marks-if-exists=io.marks
 	EOF
 	test_must_be_empty io.marks
@@ -2239,7 +2339,7 @@ test_expect_success 'R: import to output marks works without any content' '
 	feature export-marks=marks.new
 	EOF
 
-	cat input | git fast-import &&
+	git fast-import --allow-unsafe-features <input &&
 	test_cmp marks.out marks.new
 '
 
@@ -2249,7 +2349,7 @@ test_expect_success 'R: import marks prefers commandline marks file over the str
 	feature export-marks=marks.new
 	EOF
 
-	cat input | git fast-import --import-marks=marks.out &&
+	git fast-import --import-marks=marks.out --allow-unsafe-features <input &&
 	test_cmp marks.out marks.new
 '
 
@@ -2262,7 +2362,8 @@ test_expect_success 'R: multiple --import-marks= should be honoured' '
 
 	head -n2 marks.out > one.marks &&
 	tail -n +3 marks.out > two.marks &&
-	git fast-import --import-marks=one.marks --import-marks=two.marks <input &&
+	git fast-import --import-marks=one.marks --import-marks=two.marks \
+		--allow-unsafe-features <input &&
 	test_cmp marks.out combined.marks
 '
 
@@ -2275,7 +2376,7 @@ test_expect_success 'R: feature relative-marks should be honoured' '
 
 	mkdir -p .git/info/fast-import/ &&
 	cp marks.new .git/info/fast-import/relative.in &&
-	git fast-import <input &&
+	git fast-import --allow-unsafe-features <input &&
 	test_cmp marks.new .git/info/fast-import/relative.out
 '
 
@@ -2287,7 +2388,7 @@ test_expect_success 'R: feature no-relative-marks should be honoured' '
 	feature export-marks=non-relative.out
 	EOF
 
-	git fast-import <input &&
+	git fast-import --allow-unsafe-features <input &&
 	test_cmp marks.new non-relative.out
 '
 
@@ -2440,9 +2541,6 @@ test_expect_success PIPE 'R: copy using cat-file' '
 	echo $expect_id blob $expect_len >expect.response &&
 
 	rm -f blobs &&
-	cat >frontend <<-\FRONTEND_END &&
-	#!/bin/sh
-	FRONTEND_END
 
 	mkfifo blobs &&
 	(
@@ -2557,7 +2655,7 @@ test_expect_success 'R: quiet option results in no stats being output' '
 
 	EOF
 
-	cat input | git fast-import 2> output &&
+	git fast-import 2>output <input &&
 	test_must_be_empty output
 '
 
@@ -2635,7 +2733,7 @@ test_expect_success 'R: corrupt lines do not mess marks file' '
 	rm -f io.marks &&
 	blob=$(echo hi | git hash-object --stdin) &&
 	cat >expect <<-EOF &&
-	:3 0000000000000000000000000000000000000000
+	:3 $ZERO_OID
 	:1 $blob
 	:2 $blob
 	EOF
@@ -2781,7 +2879,6 @@ test_expect_success 'S: filemodify with garbage after mark must fail' '
 	COMMIT
 	M 100644 :403x hello.c
 	EOF
-	cat err &&
 	test_i18ngrep "space after mark" err
 '
 
@@ -2798,7 +2895,6 @@ test_expect_success 'S: filemodify with garbage after inline must fail' '
 	inline
 	BLOB
 	EOF
-	cat err &&
 	test_i18ngrep "nvalid dataref" err
 '
 
@@ -2812,7 +2908,6 @@ test_expect_success 'S: filemodify with garbage after sha1 must fail' '
 	COMMIT
 	M 100644 ${sha1}x hello.c
 	EOF
-	cat err &&
 	test_i18ngrep "space after SHA1" err
 '
 
@@ -2828,7 +2923,6 @@ test_expect_success 'S: notemodify with garbage after mark dataref must fail' '
 	COMMIT
 	N :202x :302
 	EOF
-	cat err &&
 	test_i18ngrep "space after mark" err
 '
 
@@ -2844,7 +2938,6 @@ test_expect_success 'S: notemodify with garbage after inline dataref must fail'
 	note blob
 	BLOB
 	EOF
-	cat err &&
 	test_i18ngrep "nvalid dataref" err
 '
 
@@ -2858,7 +2951,6 @@ test_expect_success 'S: notemodify with garbage after sha1 dataref must fail' '
 	COMMIT
 	N ${sha1}x :302
 	EOF
-	cat err &&
 	test_i18ngrep "space after SHA1" err
 '
 
@@ -2874,7 +2966,6 @@ test_expect_success 'S: notemodify with garbage after mark commit-ish must fail'
 	COMMIT
 	N :202 :302x
 	EOF
-	cat err &&
 	test_i18ngrep "after mark" err
 '
 
@@ -2908,7 +2999,6 @@ test_expect_success 'S: from with garbage after mark must fail' '
 	EOF
 
 	# now evaluate the error
-	cat err &&
 	test_i18ngrep "after mark" err
 '
 
@@ -2928,7 +3018,6 @@ test_expect_success 'S: merge with garbage after mark must fail' '
 	merge :303x
 	M 100644 :403 hello.c
 	EOF
-	cat err &&
 	test_i18ngrep "after mark" err
 '
 
@@ -2944,7 +3033,6 @@ test_expect_success 'S: tag with garbage after mark must fail' '
 	tag S
 	TAG
 	EOF
-	cat err &&
 	test_i18ngrep "after mark" err
 '
 
@@ -2955,7 +3043,6 @@ test_expect_success 'S: cat-blob with garbage after mark must fail' '
 	test_must_fail git fast-import --import-marks=marks <<-EOF 2>err &&
 	cat-blob :403x
 	EOF
-	cat err &&
 	test_i18ngrep "after mark" err
 '
 
@@ -2966,7 +3053,6 @@ test_expect_success 'S: ls with garbage after mark must fail' '
 	test_must_fail git fast-import --import-marks=marks <<-EOF 2>err &&
 	ls :302x hello.c
 	EOF
-	cat err &&
 	test_i18ngrep "space after mark" err
 '
 
@@ -2975,7 +3061,6 @@ test_expect_success 'S: ls with garbage after sha1 must fail' '
 	test_must_fail git fast-import --import-marks=marks <<-EOF 2>err &&
 	ls ${sha1}x hello.c
 	EOF
-	cat err &&
 	test_i18ngrep "space after tree-ish" err
 '
 
@@ -2999,7 +3084,7 @@ test_expect_success 'T: delete branch' '
 	git branch to-delete &&
 	git fast-import <<-EOF &&
 	reset refs/heads/to-delete
-	from 0000000000000000000000000000000000000000
+	from $ZERO_OID
 	EOF
 	test_must_fail git rev-parse --verify refs/heads/to-delete
 '
@@ -3039,6 +3124,9 @@ test_expect_success 'U: initialize for U tests' '
 
 	INPUT_END
 
+	f7id=$(echo "blob 1" | git hash-object --stdin) &&
+	f8id=$(echo "sleep well" | git hash-object --stdin) &&
+	f9id=$(echo "au revoir" | git hash-object --stdin) &&
 	git fast-import <input
 '
 
@@ -3059,7 +3147,7 @@ test_expect_success 'U: filedelete file succeeds' '
 
 test_expect_success 'U: validate file delete result' '
 	cat >expect <<-EOF &&
-	:100644 000000 2907ebb4bf85d91bf0716bb3bd8a68ef48d6da76 0000000000000000000000000000000000000000 D	good/night.txt
+	:100644 000000 $f8id $ZERO_OID D	good/night.txt
 	EOF
 
 	git diff-tree -M -r U^1 U >actual &&
@@ -3084,7 +3172,7 @@ test_expect_success 'U: filedelete directory succeeds' '
 
 test_expect_success 'U: validate directory delete result' '
 	cat >expect <<-EOF &&
-	:100644 000000 69cb75792f55123d8389c156b0b41c2ff00ed507 0000000000000000000000000000000000000000 D	good/bye.txt
+	:100644 000000 $f9id $ZERO_OID D	good/bye.txt
 	EOF
 
 	git diff-tree -M -r U^1 U >actual &&
@@ -3109,7 +3197,7 @@ test_expect_success 'U: filedelete root succeeds' '
 
 test_expect_success 'U: validate root delete result' '
 	cat >expect <<-EOF &&
-	:100644 000000 c18147dc648481eeb65dc5e66628429a64843327 0000000000000000000000000000000000000000 D	hello.c
+	:100644 000000 $f7id $ZERO_OID D	hello.c
 	EOF
 
 	git diff-tree -M -r U^1 U >actual &&
@@ -3140,13 +3228,22 @@ background_import_then_checkpoint () {
 	exec 9<>V.output
 	rm V.output
 
-	git fast-import $options <&8 >&9 &
-	echo $! >V.pid
+	(
+		git fast-import $options <&8 >&9 &
+		echo $! >&9
+		wait $!
+		echo >&2 "background fast-import terminated too early with exit code $?"
+		# Un-block the read loop in the main shell process.
+		echo >&9 UNEXPECTED
+	) &
+	sh_pid=$!
+	read fi_pid <&9
 	# We don't mind if fast-import has already died by the time the test
 	# ends.
 	test_when_finished "
 		exec 8>&-; exec 9>&-;
-		kill $(cat V.pid) && wait $(cat V.pid)
+		kill $sh_pid && wait $sh_pid
+		kill $fi_pid && wait $fi_pid
 		true"
 
 	# Start in the background to ensure we adhere strictly to (blocking)
@@ -3166,6 +3263,9 @@ background_import_then_checkpoint () {
 		then
 			error=0
 			break
+		elif test "$output" = "UNEXPECTED"
+		then
+			break
 		fi
 		# otherwise ignore cruft
 		echo >&2 "cruft: $output"
@@ -3178,7 +3278,7 @@ background_import_then_checkpoint () {
 }
 
 background_import_still_running () {
-	if ! kill -0 "$(cat V.pid)"
+	if ! kill -0 "$fi_pid"
 	then
 		echo >&2 "background fast-import terminated too early"
 		false
@@ -3319,4 +3419,113 @@ test_expect_success 'X: handling encoding' '
 	git log -1 --format=%B encoding | grep $(printf "\317\200")
 '
 
+###
+### series Y (submodules and hash algorithms)
+###
+
+cat >Y-sub-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 1000000000 +0100
+committer Full Name <user@company.tld> 1000000000 +0100
+data 24
+Test submodule commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 1000000001 +0100
+committer Full Name <user@company.tld> 1000000001 +0100
+data 24
+Test submodule commit 2
+from :2
+M 100644 :3 file
+Y_INPUT_END
+
+# Note that the submodule object IDs are intentionally not translated.
+cat >Y-main-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 2000000000 +0100
+committer Full Name <user@company.tld> 2000000000 +0100
+data 14
+Test commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 73
+[submodule "sub1"]
+	path = sub1
+	url = https://void.example.com/main.git
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 2000000001 +0100
+committer Full Name <user@company.tld> 2000000001 +0100
+data 14
+Test commit 2
+from :2
+M 100644 :3 .gitmodules
+M 160000 0712c5be7cf681388e355ef47525aaf23aee1a6d sub1
+
+blob
+mark :5
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :6
+author Full Name <user@company.tld> 2000000002 +0100
+committer Full Name <user@company.tld> 2000000002 +0100
+data 14
+Test commit 3
+from :4
+M 100644 :5 file
+M 160000 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7 sub1
+Y_INPUT_END
+
+cat >Y-marks <<\Y_INPUT_END
+:2 0712c5be7cf681388e355ef47525aaf23aee1a6d
+:4 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7
+Y_INPUT_END
+
+test_expect_success 'Y: setup' '
+	test_oid_cache <<-EOF
+	Ymaster sha1:9afed2f9161ddf416c0a1863b8b0725b00070504
+	Ymaster sha256:c0a1010da1df187b2e287654793df01b464bd6f8e3f17fc1481a7dadf84caee3
+	EOF
+'
+
+test_expect_success 'Y: rewrite submodules' '
+	git init main1 &&
+	(
+		cd main1 &&
+		git init sub2 &&
+		git -C sub2 fast-import --export-marks=../sub2-marks <../Y-sub-input &&
+		git fast-import --rewrite-submodules-from=sub:../Y-marks \
+			--rewrite-submodules-to=sub:sub2-marks <../Y-main-input &&
+		test "$(git rev-parse master)" = "$(test_oid Ymaster)"
+	)
+'
+
 test_done