[1.7.x] Fixed #22565 -- Prevented pgettext_lazy crash with bytestring input

Thanks ygbo for the report.
Backport of 142c27218 from master.

3 files changed, 21 insertions, 5 deletions

diff --git a/django/utils/translation/trans_real.py b/django/utils/translation/trans_real.py
index 6bbdbe5f20..4f07012149 100644
--- a/django/utils/translation/trans_real.py
+++ b/django/utils/translation/trans_real.py
@@ -322,7 +322,8 @@ def pgettext(context, message):
     result = ugettext(msg_with_ctxt)
     if CONTEXT_SEPARATOR in result:
         # Translation not found
-        result = message
+        # force unicode, because lazy version expects unicode
+        result = force_text(message)
     return result
 
 
diff --git a/docs/releases/1.6.5.txt b/docs/releases/1.6.5.txt
index 9abe6702cc..3c46b953b7 100644
--- a/docs/releases/1.6.5.txt
+++ b/docs/releases/1.6.5.txt
@@ -11,3 +11,6 @@ Bugfixes
 
 * Made the ``year_lookup_bounds_for_datetime_field`` Oracle backend method
   Python 3 compatible (`#22551 <http://code.djangoproject.com/ticket/22551>`_).
+
+* Fixed ``pgettext_lazy`` crash when receiving bytestring content on Python 2
+  (`#22565 <http://code.djangoproject.com/ticket/22565>`_).
diff --git a/tests/i18n/tests.py b/tests/i18n/tests.py
index 9501849e09..9edcec4774 100644
--- a/tests/i18n/tests.py
+++ b/tests/i18n/tests.py
@@ -8,6 +8,7 @@ from importlib import import_module
 import os
 import pickle
 from threading import local
+from unittest import skipUnless
 
 from django.conf import settings
 from django.template import Template, Context
@@ -29,7 +30,7 @@ from django.utils.translation import (activate, deactivate,
     ugettext, ugettext_lazy,
     ngettext_lazy,
     ungettext_lazy,
-    pgettext,
+    pgettext, pgettext_lazy,
     npgettext, npgettext_lazy,
     check_for_language,
     string_concat, LANGUAGE_SESSION_KEY)
@@ -93,9 +94,20 @@ class TranslationTests(TestCase):
         s4 = ugettext_lazy('Some other string')
         self.assertEqual(False, s == s4)
 
-        if six.PY2:
-            # On Python 2, gettext_lazy should not transform a bytestring to unicode
-            self.assertEqual(gettext_lazy(b"test").upper(), b"TEST")
+    @skipUnless(six.PY2, "No more bytestring translations on PY3")
+    def test_lazy_and_bytestrings(self):
+        # On Python 2, (n)gettext_lazy should not transform a bytestring to unicode
+        self.assertEqual(gettext_lazy(b"test").upper(), b"TEST")
+        self.assertEqual((ngettext_lazy(b"%d test", b"%d tests") % 1).upper(), b"1 TEST")
+
+        # Other versions of lazy functions always return unicode
+        self.assertEqual(ugettext_lazy(b"test").upper(), "TEST")
+        self.assertEqual((ungettext_lazy(b"%d test", b"%d tests") % 1).upper(), "1 TEST")
+        self.assertEqual(pgettext_lazy(b"context", b"test").upper(), "TEST")
+        self.assertEqual(
+            (npgettext_lazy(b"context", b"%d test", b"%d tests") % 1).upper(),
+            "1 TEST"
+        )
 
     def test_lazy_pickle(self):
         s1 = ugettext_lazy("test")