Fixed #7738: support initial values via `GET` for `SelectMutliple` in the admin.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8699 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/options.py

@@ -503,7 +503,17 @@ class ModelAdmin(BaseModelAdmin):
                 self.log_addition(request, new_object)
                 return self.response_add(request, new_object)
         else:
-            form = ModelForm(initial=dict(request.GET.items()))
+            # Prepare the dict of initial data from the request.
+            # We have to special-case M2Ms as a list of comma-separated PKs.
+            initial = dict(request.GET.items())
+            for k in initial:
+                try:
+                    f = opts.get_field(k)
+                except FieldDoesNotExist:
+                    pass
+                if isinstance(f, models.ManyToManyField):
+                    initial[k] = initial[k].split(",")
+            form = ModelForm(initial=initial)
             for FormSet in self.get_formsets(request):
                 formset = FormSet(instance=self.model())
                 formsets.append(formset)

tests/regressiontests/admin_views/tests.py

@@ -36,6 +36,14 @@ class AdminViewBasicTest(TestCase):
         response = self.client.get('/test_admin/admin/admin_views/section/add/')
         self.failUnlessEqual(response.status_code, 200)
     
+    def testAddWithGETArgs(self):
+        response = self.client.get('/test_admin/admin/admin_views/section/add/', {'name': 'My Section'})
+        self.failUnlessEqual(response.status_code, 200)
+        self.failUnless(
+            'value="My Section"' in response.content, 
+            "Couldn't find an input with the right value in the response."
+        )
+    
     def testBasicEditGet(self):
         """
         A smoke test to ensureGET on the change_view works.