t9822: skip tests if file names cannot be ISO-8859-1 encoded

Most notably, it seems that macOS' APFS does not allow that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: dscho

t/t9822-git-p4-path-encoding.sh

@@ -7,6 +7,13 @@ test_description='Clone repositories with non ASCII paths'
 UTF8_ESCAPED="a-\303\244_o-\303\266_u-\303\274.txt"
 ISO8859_ESCAPED="a-\344_o-\366_u-\374.txt"
 
+ISO8859="$(printf "$ISO8859_ESCAPED")" &&
+echo content123 >"$ISO8859" &&
+rm "$ISO8859" || {
+	skip_all="fs does not accept ISO-8859-1 filenames"
+	test_done
+}
+
 test_expect_success 'start p4d' '
 	start_p4d
 '