Fixed #25677 -- Prevented decoding errors in/after Popen calls

Thanks Gavin Wahl for the report and Tim Graham for the review.

tests/i18n/commands/locale/ko/LC_MESSAGES/django.po

@@ -0,0 +1,24 @@
+# This file intentionally contains a wrong msgstr that will produce
+# a msgfmt error.
+# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
+# This file is distributed under the same license as the PACKAGE package.
+# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: PACKAGE VERSION\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2015-11-04 12:01-0700\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language-Team: LANGUAGE <LL@li.org>\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Language: \n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+
+#: foo/password_validation.py:17
+#, python-brace-format
+msgid "Your password must contain a symbol: {symbols}"
+msgstr "[Ẏǿŭř ƥȧşşẇǿřḓ ḿŭşŧ ƈǿƞŧȧīƞ ȧ şẏḿƀǿŀ: {şẏḿƀǿŀş} ΐΰϖΐ ϖΐẛϕϐ]"

tests/i18n/test_compilation.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import unicode_literals
 
 import gettext as gettext_module
 import os
@@ -12,7 +13,7 @@ from django.core.management import (
 from django.core.management.utils import find_command
 from django.test import SimpleTestCase, override_settings
 from django.test.utils import captured_stderr, captured_stdout
-from django.utils import translation
+from django.utils import six, translation
 from django.utils._os import upath
 from django.utils.encoding import force_text
 from django.utils.six import StringIO
@@ -154,17 +155,26 @@ class ExcludedLocaleCompilationTests(MessageCompilationTests):
 
 
 class CompilationErrorHandling(MessageCompilationTests):
-
-    LOCALE = 'ja'
-    MO_FILE = 'locale/%s/LC_MESSAGES/django.mo' % LOCALE
-
-    def setUp(self):
-        super(CompilationErrorHandling, self).setUp()
-        self.addCleanup(self.rmfile, os.path.join(self.test_dir, self.MO_FILE))
-
     def test_error_reported_by_msgfmt(self):
+        # po file contains wrong po formatting.
+        mo_file = 'locale/ja/LC_MESSAGES/django.mo'
+        self.addCleanup(self.rmfile, os.path.join(self.test_dir, mo_file))
         with self.assertRaises(CommandError):
-            call_command('compilemessages', locale=[self.LOCALE], stdout=StringIO())
+            call_command('compilemessages', locale=['ja'], verbosity=0)
+
+    def test_msgfmt_error_including_non_ascii(self):
+        # po file contains invalid msgstr content (triggers non-ascii error content).
+        mo_file = 'locale/ko/LC_MESSAGES/django.mo'
+        self.addCleanup(self.rmfile, os.path.join(self.test_dir, mo_file))
+        if six.PY2:
+            # Various assertRaises on PY2 don't support unicode error messages.
+            try:
+                call_command('compilemessages', locale=['ko'], verbosity=0)
+            except CommandError as err:
+                self.assertIn("'<EFBFBD>' cannot start a field name", six.text_type(err))
+        else:
+            with self.assertRaisesMessage(CommandError, "'<EFBFBD>' cannot start a field name"):
+                call_command('compilemessages', locale=['ko'], verbosity=0)
 
 
 class ProjectAndAppTests(MessageCompilationTests):