Add test to ensure multibyte chars work with the usage substring

tests/scripts/multibyte_doc.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+DOC="μprog - A tiny program
+Usage: uprog.sh [options]
+
+Options:
+  -d --do THINGTODO  Do the thing
+"
+"DOCOPT PARAMS"
+eval "$(docopt "$@")"

tests/test_scriptpatching.py

@@ -406,3 +406,11 @@ def test_option_after_invocation(monkeypatch, capsys):
   assert (
     'STDIN:4 $DOCOPT_ADD_HELP has no effect when specified after invoking docopt, '
     + 'make sure to place docopt options before calling `eval "$(docopt "$@")"`.') in err
+
+
+def test_multibyte_doc(monkeypatch, capsys, bash):
+  run = patch_file(monkeypatch, capsys, 'multibyte_doc.sh')
+  code, out, err = run(bash, 'invalid')
+  assert err == 'Usage: uprog.sh [options]\n'
+  assert code == 1
+  assert out == ''