Merge branch 'sg/doc-test-must-fail-args'

Devdoc update.

* sg/doc-test-must-fail-args:
  t: document 'test_must_fail ok=<signal-name>'

t/test-lib-functions.sh

@@ -610,6 +610,14 @@ list_contains () {
 #
 # Writing this as "! git checkout ../outerspace" is wrong, because
 # the failure could be due to a segv.  We want a controlled failure.
+#
+# Accepts the following options:
+#
+#   ok=<signal-name>[,<...>]:
+#     Don't treat an exit caused by the given signal as error.
+#     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.)
 
 test_must_fail () {
 	case "$1" in
@@ -656,6 +664,8 @@ test_must_fail () {
 #
 # Writing "git config --unset all.configuration || :" would be wrong,
 # because we want to notice if it fails due to segv.
+#
+# Accepts the same options as test_must_fail.
 
 test_might_fail () {
 	test_must_fail ok=success "$@"