Fixed #27067 -- Deprecated string_concat() in favor of format_lazy().

4 files changed, 17 insertions, 10 deletions

diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 052a1d5a9a..11b5585f7a 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -43,9 +43,9 @@ from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.html import escape, format_html
 from django.utils.http import urlencode, urlquote
 from django.utils.safestring import mark_safe
-from django.utils.text import capfirst, get_text_list
+from django.utils.text import capfirst, format_lazy, get_text_list
 from django.utils.translation import (
-    override as translation_override, string_concat, ugettext as _, ungettext,
+    override as translation_override, ugettext as _, ungettext,
 )
 from django.views.decorators.csrf import csrf_protect
 from django.views.generic import RedirectView
@@ -258,7 +258,7 @@ class BaseModelAdmin(six.with_metaclass(forms.MediaDefiningClass)):
         if isinstance(form_field.widget, SelectMultiple) and not isinstance(form_field.widget, CheckboxSelectMultiple):
             msg = _('Hold down "Control", or "Command" on a Mac, to select more than one.')
             help_text = form_field.help_text
-            form_field.help_text = string_concat(help_text, ' ', msg) if help_text else msg
+            form_field.help_text = format_lazy('{} {}', help_text, msg) if help_text else msg
         return form_field
 
     def get_view_on_site_url(self, obj=None):
diff --git a/django/contrib/postgres/utils.py b/django/contrib/postgres/utils.py
index 1563149c7e..a2bbb72f36 100644
--- a/django/contrib/postgres/utils.py
+++ b/django/contrib/postgres/utils.py
@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 from django.core.exceptions import ValidationError
 from django.utils.functional import SimpleLazyObject
-from django.utils.translation import string_concat
+from django.utils.text import format_lazy
 
 
 def prefix_validation_error(error, prefix, code, params):
@@ -15,10 +15,11 @@ def prefix_validation_error(error, prefix, code, params):
         return ValidationError(
             # We can't simply concatenate messages since they might require
             # their associated parameters to be expressed correctly which
-            # is not something `string_concat` does. For example, proxied
+            # is not something `format_lazy` does. For example, proxied
             # ungettext calls require a count parameter and are converted
             # to an empty string if they are missing it.
-            message=string_concat(
+            message=format_lazy(
+                '{}{}',
                 SimpleLazyObject(lambda: prefix % params),
                 SimpleLazyObject(lambda: error.message % error_params),
             ),
diff --git a/django/db/models/options.py b/django/db/models/options.py
index 38f2fcfefc..f53d3bb59f 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -22,8 +22,8 @@ from django.utils.encoding import (
     force_text, python_2_unicode_compatible, smart_text,
 )
 from django.utils.functional import cached_property
-from django.utils.text import camel_case_to_spaces
-from django.utils.translation import override, string_concat
+from django.utils.text import camel_case_to_spaces, format_lazy
+from django.utils.translation import override
 
 NOT_PROVIDED = object()
 
@@ -197,7 +197,7 @@ class Options(object):
             # verbose_name_plural is a special case because it uses a 's'
             # by default.
             if self.verbose_name_plural is None:
-                self.verbose_name_plural = string_concat(self.verbose_name, 's')
+                self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
 
             # order_with_respect_and ordering are mutually exclusive.
             self._ordering_clash = bool(self.ordering and self.order_with_respect_to)
@@ -206,7 +206,7 @@ class Options(object):
             if meta_attrs != {}:
                 raise TypeError("'class Meta' got invalid attribute(s): %s" % ','.join(meta_attrs.keys()))
         else:
-            self.verbose_name_plural = string_concat(self.verbose_name, 's')
+            self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
         del self.meta
 
         # If the db_table wasn't provided, use the app_label + model_name.
diff --git a/django/utils/translation/__init__.py b/django/utils/translation/__init__.py
index c42182d96d..9154ceeb7b 100644
--- a/django/utils/translation/__init__.py
+++ b/django/utils/translation/__init__.py
@@ -4,9 +4,11 @@ Internationalization support.
 from __future__ import unicode_literals
 
 import re
+import warnings
 
 from django.utils import six
 from django.utils.decorators import ContextDecorator
+from django.utils.deprecation import RemovedInDjango21Warning
 from django.utils.encoding import force_text
 from django.utils.functional import lazy
 
@@ -224,6 +226,10 @@ def _string_concat(*strings):
     Lazy variant of string concatenation, needed for translations that are
     constructed from multiple parts.
     """
+    warnings.warn(
+        'django.utils.translate.string_concat() is deprecated in '
+        'favor of django.utils.text.format_lazy().',
+        RemovedInDjango21Warning, stacklevel=2)
     return ''.join(force_text(s) for s in strings)
 string_concat = lazy(_string_concat, six.text_type)