cp: Add tests involving sparse files.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D38290

bin/cp/tests/cp_test.sh

@@ -199,6 +199,91 @@ recursive_link_Lflag_body()
 	    '(' ! -L foo-mirror/foo/baz ')'
 }
 
+file_is_sparse()
+{
+	atf_check test "$(stat -f "%b" "$1")" != "$(stat -f "%z" "$1")"
+}
+
+files_are_equal()
+{
+	atf_check test "$(stat -f "%d %i" "$1")" != "$(stat -f "%d %i" "$2")"
+	atf_check cmp "$1" "$2"
+}
+
+atf_test_case sparse_leading_hole
+sparse_leading_hole_body()
+{
+	# A one-megabyte hole followed by one megabyte of data
+	truncate -s 1M foo
+	seq -f%015g 65536 >>foo
+	file_is_sparse foo
+
+	atf_check cp foo bar
+	files_are_equal foo bar
+	file_is_sparse bar
+}
+
+atf_test_case sparse_multiple_holes
+sparse_multiple_holes_body()
+{
+	# Three one-megabyte blocks of data preceded, separated, and
+	# followed by one-megabyte holes
+	truncate -s 1M foo
+	seq -f%015g >>foo
+	truncate -s 3M foo
+	seq -f%015g >>foo
+	truncate -s 5M foo
+	seq -f%015g >>foo
+	truncate -s 7M foo
+	file_is_sparse foo
+
+	atf_check cp foo bar
+	files_are_equal foo bar
+	file_is_sparse bar
+}
+
+atf_test_case sparse_only_hole
+sparse_only_hole_body()
+{
+	# A one-megabyte hole
+	truncate -s 1M foo
+	file_is_sparse foo
+
+	atf_check cp foo bar
+	files_are_equal foo bar
+	file_is_sparse bar
+}
+
+atf_test_case sparse_to_dev
+sparse_to_dev_body()
+{
+	# Three one-megabyte blocks of data preceded, separated, and
+	# followed by one-megabyte holes
+	truncate -s 1M foo
+	seq -f%015g >>foo
+	truncate -s 3M foo
+	seq -f%015g >>foo
+	truncate -s 5M foo
+	seq -f%015g >>foo
+	truncate -s 7M foo
+	file_is_sparse foo
+
+	atf_check -o file:foo cp foo /dev/stdout
+}
+
+atf_test_case sparse_trailing_hole
+sparse_trailing_hole_body()
+{
+	# One megabyte of data followed by a one-megabyte hole
+	seq -f%015g 65536 >foo
+	truncate -s 2M foo
+	file_is_sparse foo
+
+	atf_check cp foo bar
+	files_are_equal foo bar
+	file_is_sparse bar
+}
+
 atf_test_case standalone_Pflag
 standalone_Pflag_body()
 {
@@ -221,5 +306,10 @@ atf_init_test_cases()
 	atf_add_test_case recursive_link_dflt
 	atf_add_test_case recursive_link_Hflag
 	atf_add_test_case recursive_link_Lflag
+	atf_add_test_case sparse_leading_hole
+	atf_add_test_case sparse_multiple_holes
+	atf_add_test_case sparse_only_hole
+	atf_add_test_case sparse_to_dev
+	atf_add_test_case sparse_trailing_hole
 	atf_add_test_case standalone_Pflag
 }