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, 209 insertions, 23 deletions

diff --git a/third_party/git/t/test-lib-functions.sh b/third_party/git/t/test-lib-functions.sh
index e0b3f28d3a96..8d59b90348ea 100644
--- a/third_party/git/t/test-lib-functions.sh
+++ b/third_party/git/t/test-lib-functions.sh
@@ -228,9 +228,11 @@ test_commit () {
 # can be a tag pointing to the commit-to-merge.
 
 test_merge () {
+	label="$1" &&
+	shift &&
 	test_tick &&
-	git merge -m "$1" "$2" &&
-	git tag "$1"
+	git merge -m "$label" "$@" &&
+	git tag "$label"
 }
 
 # Efficiently create <nr> commits, each with a unique number (from 1 to <nr>
@@ -306,7 +308,7 @@ test_commit_bulk () {
 	total=$1
 
 	add_from=
-	if git -C "$indir" rev-parse --verify "$ref"
+	if git -C "$indir" rev-parse --quiet --verify "$ref"
 	then
 		add_from=t
 	fi
@@ -580,7 +582,7 @@ test_expect_failure () {
 	export test_prereq
 	if ! test_skip "$@"
 	then
-		say >&3 "checking known breakage: $2"
+		say >&3 "checking known breakage of $TEST_NUMBER.$test_count '$1': $2"
 		if test_run_ "$2" expecting_failure
 		then
 			test_known_broken_ok_ "$1"
@@ -600,7 +602,7 @@ test_expect_success () {
 	export test_prereq
 	if ! test_skip "$@"
 	then
-		say >&3 "expecting success: $2"
+		say >&3 "expecting success of $TEST_NUMBER.$test_count '$1': $2"
 		if test_run_ "$2"
 		then
 			test_ok_ "$1"
@@ -796,6 +798,37 @@ list_contains () {
 	return 1
 }
 
+# Returns success if the arguments indicate that a command should be
+# accepted by test_must_fail(). If the command is run with env, the env
+# and its corresponding variable settings will be stripped before we
+# test the command being run.
+test_must_fail_acceptable () {
+	if test "$1" = "env"
+	then
+		shift
+		while test $# -gt 0
+		do
+			case "$1" in
+			*?=*)
+				shift
+				;;
+			*)
+				break
+				;;
+			esac
+		done
+	fi
+
+	case "$1" in
+	git|__git*|test-tool|test_terminal)
+		return 0
+		;;
+	*)
+		return 1
+		;;
+	esac
+}
+
 # This is not among top-level (test_expect_success | test_expect_failure)
 # but is a prefix that can be used in the test script, like:
 #
@@ -815,6 +848,17 @@ list_contains () {
 #     Multiple signals can be specified as a comma separated list.
 #     Currently recognized signal names are: sigpipe, success.
 #     (Don't use 'success', use 'test_might_fail' instead.)
+#
+# Do not use this to run anything but "git" and other specific testable
+# commands (see test_must_fail_acceptable()).  We are not in the
+# business of vetting system supplied commands -- in other words, this
+# is wrong:
+#
+#    test_must_fail grep pattern output
+#
+# Instead use '!':
+#
+#    ! grep pattern output
 
 test_must_fail () {
 	case "$1" in
@@ -826,6 +870,11 @@ test_must_fail () {
 		_test_ok=
 		;;
 	esac
+	if ! test_must_fail_acceptable "$@"
+	then
+		echo >&7 "test_must_fail: only 'git' is allowed: $*"
+		return 1
+	fi
 	"$@" 2>&7
 	exit_code=$?
 	if test $exit_code -eq 0 && ! list_contains "$_test_ok" success
@@ -903,7 +952,13 @@ test_expect_code () {
 # - not all diff versions understand "-u"
 
 test_cmp() {
-	$GIT_TEST_CMP "$@"
+	test $# -eq 2 || BUG "test_cmp requires two arguments"
+	if ! eval "$GIT_TEST_CMP" '"$@"'
+	then
+		test "x$1" = x- || test -e "$1" || BUG "test_cmp '$1' missing"
+		test "x$2" = x- || test -e "$2" || BUG "test_cmp '$2' missing"
+		return 1
+	fi
 }
 
 # Check that the given config key has the expected value.
@@ -932,7 +987,13 @@ test_cmp_config() {
 # test_cmp_bin - helper to compare binary files
 
 test_cmp_bin() {
-	cmp "$@"
+	test $# -eq 2 || BUG "test_cmp_bin requires two arguments"
+	if ! cmp "$@"
+	then
+		test "x$1" = x- || test -e "$1" || BUG "test_cmp_bin '$1' missing"
+		test "x$2" = x- || test -e "$2" || BUG "test_cmp_bin '$2' missing"
+		return 1
+	fi
 }
 
 # Use this instead of test_cmp to compare files that contain expected and
@@ -1010,19 +1071,30 @@ test_must_be_empty () {
 	fi
 }
 
-# Tests that its two parameters refer to the same revision
+# Tests that its two parameters refer to the same revision, or if '!' is
+# provided first, that its other two parameters refer to different
+# revisions.
 test_cmp_rev () {
+	local op='=' wrong_result=different
+
+	if test $# -ge 1 && test "x$1" = 'x!'
+	then
+	    op='!='
+	    wrong_result='the same'
+	    shift
+	fi
 	if test $# != 2
 	then
 		error "bug in the test script: test_cmp_rev requires two revisions, but got $#"
 	else
 		local r1 r2
 		r1=$(git rev-parse --verify "$1") &&
-		r2=$(git rev-parse --verify "$2") &&
-		if test "$r1" != "$r2"
+		r2=$(git rev-parse --verify "$2") || return 1
+
+		if ! test "$r1" "$op" "$r2"
 		then
 			cat >&4 <<-EOF
-			error: two revisions point to different objects:
+			error: two revisions point to $wrong_result objects:
 			  '$1': $r1
 			  '$2': $r2
 			EOF
@@ -1173,6 +1245,34 @@ perl () {
 	command "$PERL_PATH" "$@" 2>&7
 } 7>&2 2>&4
 
+# Given the name of an environment variable with a bool value, normalize
+# its value to a 0 (true) or 1 (false or empty string) return code.
+#
+#   test_bool_env GIT_TEST_HTTPD <default-value>
+#
+# Return with code corresponding to the given default value if the variable
+# is unset.
+# Abort the test script if either the value of the variable or the default
+# are not valid bool values.
+
+test_bool_env () {
+	if test $# != 2
+	then
+		BUG "test_bool_env requires two parameters (variable name and default value)"
+	fi
+
+	git env--helper --type=bool --default="$2" --exit-code "$1"
+	ret=$?
+	case $ret in
+	0|1)	# unset or valid bool value
+		;;
+	*)	# invalid bool value or something unexpected
+		error >&7 "test_bool_env requires bool values both for \$$1 and for the default fallback"
+		;;
+	esac
+	return $ret
+}
+
 # Exit the test suite, either by skipping all remaining tests or by
 # exiting with an error. If our prerequisite variable $1 falls back
 # on a default assume we were opportunistically trying to set up some
@@ -1181,7 +1281,7 @@ perl () {
 # The error/skip message should be given by $2.
 #
 test_skip_or_die () {
-	if ! git env--helper --type=bool --default=false --exit-code $1
+	if ! test_bool_env "$1" false
 	then
 		skip_all=$2
 		test_done
@@ -1321,14 +1421,22 @@ nongit () {
 	)
 } 7>&2 2>&4
 
-# convert stdin to pktline representation; note that empty input becomes an
-# empty packet, not a flush packet (for that you can just print 0000 yourself).
+# convert function arguments or stdin (if not arguments given) to pktline
+# representation. If multiple arguments are given, they are separated by
+# whitespace and put in a single packet. Note that data containing NULs must be
+# given on stdin, and that empty input becomes an empty packet, not a flush
+# packet (for that you can just print 0000 yourself).
 packetize() {
-	cat >packetize.tmp &&
-	len=$(wc -c <packetize.tmp) &&
-	printf '%04x%s' "$(($len + 4))" &&
-	cat packetize.tmp &&
-	rm -f packetize.tmp
+	if test $# -gt 0
+	then
+		packet="$*"
+		printf '%04x%s' "$((4 + ${#packet}))" "$packet"
+	else
+		perl -e '
+			my $packet = do { local $/; <STDIN> };
+			printf "%04x%s", 4 + length($packet), $packet;
+		'
+	fi
 }
 
 # Parse the input as a series of pktlines, writing the result to stdout.
@@ -1368,9 +1476,7 @@ test_set_hash () {
 
 # Detect the hash algorithm in use.
 test_detect_hash () {
-	# Currently we only support SHA-1, but in the future this function will
-	# actually detect the algorithm in use.
-	test_hash_algo='sha1'
+	test_hash_algo="${GIT_TEST_DEFAULT_HASH:-sha1}"
 }
 
 # Load common hash metadata and common placeholder object IDs for use with
@@ -1419,7 +1525,17 @@ test_oid_cache () {
 # Look up a per-hash value based on a key ($1).  The value must have been loaded
 # by test_oid_init or test_oid_cache.
 test_oid () {
-	local var="test_oid_${test_hash_algo}_$1" &&
+	local algo="${test_hash_algo}" &&
+
+	case "$1" in
+	--hash=*)
+		algo="${1#--hash=}" &&
+		shift;;
+	*)
+		;;
+	esac &&
+
+	local var="test_oid_${algo}_$1" &&
 
 	# If the variable is unset, we must be missing an entry for this
 	# key-hash pair, so exit with an error.
@@ -1475,3 +1591,73 @@ test_set_port () {
 	port=$(($port + ${GIT_TEST_STRESS_JOB_NR:-0}))
 	eval $var=$port
 }
+
+# Compare a file containing rev-list bitmap traversal output to its non-bitmap
+# counterpart. You can't just use test_cmp for this, because the two produce
+# subtly different output:
+#
+#   - regular output is in traversal order, whereas bitmap is split by type,
+#     with non-packed objects at the end
+#
+#   - regular output has a space and the pathname appended to non-commit
+#     objects; bitmap output omits this
+#
+# This function normalizes and compares the two. The second file should
+# always be the bitmap output.
+test_bitmap_traversal () {
+	if test "$1" = "--no-confirm-bitmaps"
+	then
+		shift
+	elif cmp "$1" "$2"
+	then
+		echo >&2 "identical raw outputs; are you sure bitmaps were used?"
+		return 1
+	fi &&
+	cut -d' ' -f1 "$1" | sort >"$1.normalized" &&
+	sort "$2" >"$2.normalized" &&
+	test_cmp "$1.normalized" "$2.normalized" &&
+	rm -f "$1.normalized" "$2.normalized"
+}
+
+# Tests for the hidden file attribute on Windows
+test_path_is_hidden () {
+	test_have_prereq MINGW ||
+	BUG "test_path_is_hidden can only be used on Windows"
+
+	# Use the output of `attrib`, ignore the absolute path
+	case "$("$SYSTEMROOT"/system32/attrib "$1")" in *H*?:*) return 0;; esac
+	return 1
+}
+
+# Check that the given command was invoked as part of the
+# trace2-format trace on stdin.
+#
+#	test_subcommand [!] <command> <args>... < <trace>
+#
+# For example, to look for an invocation of "git upload-pack
+# /path/to/repo"
+#
+#	GIT_TRACE2_EVENT=event.log git fetch ... &&
+#	test_subcommand git upload-pack "$PATH" <event.log
+#
+# If the first parameter passed is !, this instead checks that
+# the given command was not called.
+#
+test_subcommand () {
+	local negate=
+	if test "$1" = "!"
+	then
+		negate=t
+		shift
+	fi
+
+	local expr=$(printf '"%s",' "$@")
+	expr="${expr%,}"
+
+	if test -n "$negate"
+	then
+		! grep "\[$expr\]"
+	else
+		grep "\[$expr\]"
+	fi
+}