From af953c45cc56df28d02675e196eca1b54ce28a43 Mon Sep 17 00:00:00 2001
From: Tim Graham <timograham@gmail.com>
Date: Thu, 29 Aug 2013 09:39:31 -0400
Subject: [PATCH] Fixed #16433 -- Fixed a help_text/read only field interaction
 that caused an admin crash.

Thanks chris at cogdon.org for the report and admackin for the patch.
---
 django/contrib/admin/util.py |  9 +++++++--
 tests/admin_views/admin.py   |  6 +++++-
 tests/admin_views/models.py  |  2 +-
 tests/admin_views/tests.py   | 14 +++++++++++++-
 4 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/django/contrib/admin/util.py b/django/contrib/admin/util.py
index a36c8c13c8..030e6b682c 100644
--- a/django/contrib/admin/util.py
+++ b/django/contrib/admin/util.py
@@ -327,10 +327,15 @@ def label_for_field(name, model, model_admin=None, return_attr=False):
 
 
 def help_text_for_field(name, model):
+    help_text = ""
     try:
-        help_text = model._meta.get_field_by_name(name)[0].help_text
+        field_data = model._meta.get_field_by_name(name)
     except models.FieldDoesNotExist:
-        help_text = ""
+        pass
+    else:
+        field = field_data[0]
+        if not isinstance(field, RelatedObject):
+            help_text = field.help_text
     return smart_text(help_text)
 
 
diff --git a/tests/admin_views/admin.py b/tests/admin_views/admin.py
index 193b64505c..b2da23f08e 100644
--- a/tests/admin_views/admin.py
+++ b/tests/admin_views/admin.py
@@ -450,6 +450,10 @@ class GadgetAdmin(admin.ModelAdmin):
         return CustomChangeList
 
 
+class ToppingAdmin(admin.ModelAdmin):
+    readonly_fields = ('pizzas',)
+
+
 class PizzaAdmin(admin.ModelAdmin):
     readonly_fields = ('toppings',)
 
@@ -763,7 +767,7 @@ site.register(Book, inlines=[ChapterInline])
 site.register(Promo)
 site.register(ChapterXtra1, ChapterXtra1Admin)
 site.register(Pizza, PizzaAdmin)
-site.register(Topping)
+site.register(Topping, ToppingAdmin)
 site.register(Album, AlbumAdmin)
 site.register(Question)
 site.register(Answer)
diff --git a/tests/admin_views/models.py b/tests/admin_views/models.py
index 1accf46819..6483fc8717 100644
--- a/tests/admin_views/models.py
+++ b/tests/admin_views/models.py
@@ -495,7 +495,7 @@ class Topping(models.Model):
 
 class Pizza(models.Model):
     name = models.CharField(max_length=20)
-    toppings = models.ManyToManyField('Topping')
+    toppings = models.ManyToManyField('Topping', related_name='pizzas')
 
 
 class Album(models.Model):
diff --git a/tests/admin_views/tests.py b/tests/admin_views/tests.py
index 2b4ed7b3f5..aa5f9ecebc 100644
--- a/tests/admin_views/tests.py
+++ b/tests/admin_views/tests.py
@@ -50,7 +50,8 @@ from .models import (Article, BarAccount, CustomArticle, EmptyModel, FooAccount,
     OtherStory, ComplexSortedPerson, PluggableSearchPerson, Parent, Child, AdminOrderedField,
     AdminOrderedModelMethod, AdminOrderedAdminMethod, AdminOrderedCallable,
     Report, MainPrepopulated, RelatedPrepopulated, UnorderedObject,
-    Simple, UndeletableObject, UnchangeableObject, Choice, ShortMessage, Telegram)
+    Simple, UndeletableObject, UnchangeableObject, Choice, ShortMessage,
+    Telegram, Pizza, Topping)
 from .admin import site, site2
 
 
@@ -3638,6 +3639,17 @@ class ReadonlyTest(TestCase):
         self.assertContains(response, '<p>No opinion</p>', html=True)
         self.assertNotContains(response, '<p>(None)</p>')
 
+    def test_readonly_backwards_ref(self):
+        """
+        Regression test for #16433 - backwards references for related objects
+        broke if the related field is read-only due to the help_text attribute
+        """
+        topping = Topping.objects.create(name='Salami')
+        pizza = Pizza.objects.create(name='Americano')
+        pizza.toppings.add(topping)
+        response = self.client.get('/test_admin/admin/admin_views/topping/add/')
+        self.assertEqual(response.status_code, 200)
+
 
 @override_settings(PASSWORD_HASHERS=('django.contrib.auth.hashers.SHA1PasswordHasher',))
 class RawIdFieldsTest(TestCase):