Merge remote-tracking branch 'core/master' into schema-alteration

Conflicts:
	django/db/backends/__init__.py
	django/db/models/fields/related.py
	tests/field_deconstruction/tests.py

4 files changed, 13 insertions, 20 deletions

diff --git a/django/forms/fields.py b/django/forms/fields.py
index 52bcf9485c..c4bc3fa88c 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -370,14 +370,8 @@ class DecimalField(IntegerField):
 
     def widget_attrs(self, widget):
         attrs = super(DecimalField, self).widget_attrs(widget)
-        if isinstance(widget, NumberInput):
-            if self.max_digits is not None:
-                max_length = self.max_digits + 1  # for the sign
-                if self.decimal_places is None or self.decimal_places > 0:
-                    max_length += 1  # for the dot
-                attrs['maxlength'] = max_length
-            if self.decimal_places:
-                attrs['step'] = '0.%s1' % ('0' * (self.decimal_places-1))
+        if isinstance(widget, NumberInput) and self.decimal_places:
+            attrs['step'] = '0.%s1' % ('0' * (self.decimal_places - 1))
         return attrs
 
 
diff --git a/django/forms/formsets.py b/django/forms/formsets.py
index edd362c595..cb3126e6d7 100644
--- a/django/forms/formsets.py
+++ b/django/forms/formsets.py
@@ -4,8 +4,9 @@ from django.core.exceptions import ValidationError
 from django.forms import Form
 from django.forms.fields import IntegerField, BooleanField
 from django.forms.util import ErrorList
-from django.forms.widgets import Media, HiddenInput
+from django.forms.widgets import HiddenInput
 from django.utils.encoding import python_2_unicode_compatible
+from django.utils.functional import cached_property
 from django.utils.safestring import mark_safe
 from django.utils import six
 from django.utils.six.moves import xrange
@@ -55,8 +56,6 @@ class BaseFormSet(object):
         self.error_class = error_class
         self._errors = None
         self._non_form_errors = None
-        # construct the forms in the formset
-        self._construct_forms()
 
     def __str__(self):
         return self.as_table()
@@ -125,12 +124,14 @@ class BaseFormSet(object):
             initial_forms = len(self.initial) if self.initial else 0
         return initial_forms
 
-    def _construct_forms(self):
-        # instantiate all the forms and put them in self.forms
-        self.forms = []
+    @cached_property
+    def forms(self):
+        """
+        Instantiate forms at first property access.
+        """
         # DoS protection is included in total_form_count()
-        for i in xrange(self.total_form_count()):
-            self.forms.append(self._construct_form(i))
+        forms = [self._construct_form(i) for i in xrange(self.total_form_count())]
+        return forms
 
     def _construct_form(self, i, **kwargs):
         """
diff --git a/django/forms/util.py b/django/forms/util.py
index 568cdd1086..0a73320f83 100644
--- a/django/forms/util.py
+++ b/django/forms/util.py
@@ -3,7 +3,6 @@ from __future__ import unicode_literals
 from django.conf import settings
 from django.utils.html import format_html, format_html_join
 from django.utils.encoding import force_text, python_2_unicode_compatible
-from django.utils.safestring import mark_safe
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 from django.utils import six
diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index aca4a457af..38d1b99b0d 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -5,7 +5,6 @@ HTML Widget classes
 from __future__ import absolute_import, unicode_literals
 
 import copy
-import datetime
 from itertools import chain
 try:
     from urllib.parse import urljoin
@@ -16,8 +15,8 @@ import warnings
 from django.conf import settings
 from django.forms.util import flatatt, to_current_timezone
 from django.utils.datastructures import MultiValueDict, MergeDict
-from django.utils.html import conditional_escape, format_html, format_html_join
-from django.utils.translation import ugettext, ugettext_lazy
+from django.utils.html import conditional_escape, format_html
+from django.utils.translation import ugettext_lazy
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.safestring import mark_safe
 from django.utils import datetime_safe, formats, six