From addbf63fa41423b405c6d3718151e1550852a7c8 Mon Sep 17 00:00:00 2001
From: Sergey <mr.kregi@yandex.ru>
Date: Mon, 29 Oct 2018 17:04:24 +0300
Subject: [PATCH] Pass extra_context to history_form_view

---
 AUTHORS.rst                              |  3 +-
 CHANGES.rst                              |  1 +
 simple_history/admin.py                  |  3 +-
 simple_history/tests/tests/test_admin.py | 57 ++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/AUTHORS.rst b/AUTHORS.rst
index 6ef8534e6..93db638bb 100644
--- a/AUTHORS.rst
+++ b/AUTHORS.rst
@@ -73,9 +73,10 @@ Authors
 - Ross Lote
 - Ross Mechanic (`rossmechanic <https://github.com/rossmechanic>`_)
 - Ross Rogers
+- Sergey Ozeranskiy (`ozeranskiy <https://github.com/ozeranskiy>`_)
 - Shane Engelman
-- Steven Klass
 - Steeve Chailloux
+- Steven Klass
 - Tommy Beadle (`tbeadle <https://github.com/tbeadle>`_)
 - Trey Hunner (`treyhunner <https://github.com/treyhunner>`_)
 - Ulysses Vilela
diff --git a/CHANGES.rst b/CHANGES.rst
index 782ca5c7d..fa49f6161 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -10,6 +10,7 @@ Unreleased
 - Raise warning if HistoricalRecords(inherit=False) is in an abstract model (gh-341)
 - Ensure custom arguments for fields are included in historical models' fields (gh-431)
 - Add german translations
+- Add `extra_context` parameter to history_form_view (gh-467)
 
 2.5.1 (2018-10-19)
 ------------------
diff --git a/simple_history/admin.py b/simple_history/admin.py
index 870c00ade..e8d805d8f 100644
--- a/simple_history/admin.py
+++ b/simple_history/admin.py
@@ -109,7 +109,7 @@ def response_change(self, request, obj):
         else:
             return super(SimpleHistoryAdmin, self).response_change(request, obj)
 
-    def history_form_view(self, request, object_id, version_id):
+    def history_form_view(self, request, object_id, version_id, extra_context=None):
         request.current_app = self.admin_site.name
         original_opts = self.model._meta
         model = getattr(
@@ -190,6 +190,7 @@ def history_form_view(self, request, object_id, version_id):
             "root_path": getattr(self.admin_site, "root_path", None),
         }
         context.update(self.admin_site.each_context(request))
+        context.update(extra_context or {})
         extra_kwargs = {}
         return render(
             request, self.object_history_form_template, context, **extra_kwargs
diff --git a/simple_history/tests/tests/test_admin.py b/simple_history/tests/tests/test_admin.py
index 5ea2ca127..4881cee74 100644
--- a/simple_history/tests/tests/test_admin.py
+++ b/simple_history/tests/tests/test_admin.py
@@ -630,3 +630,60 @@ def test_history_form_view_getting_history_abstract_external(self):
         mock_render.assert_called_once_with(
             request, admin.object_history_form_template, context
         )
+
+    def test_history_form_view_accepts_additional_context(self):
+        request = RequestFactory().post("/")
+        request.session = "session"
+        request._messages = FallbackStorage(request)
+        request.user = self.user
+
+        poll = Poll.objects.create(question="why?", pub_date=today)
+        poll.question = "how?"
+        poll.save()
+        history = poll.history.all()[0]
+
+        admin_site = AdminSite()
+        admin = SimpleHistoryAdmin(Poll, admin_site)
+
+        with patch("simple_history.admin.render") as mock_render:
+            admin.history_form_view(
+                request,
+                poll.id,
+                history.pk,
+                extra_context={"anything_else": "will be merged into context"},
+            )
+
+        context = {
+            # Verify this is set for original object
+            "anything_else": "will be merged into context",
+            "original": poll,
+            "change_history": False,
+            "title": "Revert %s" % force_text(poll),
+            "adminform": ANY,
+            "object_id": poll.id,
+            "is_popup": False,
+            "media": ANY,
+            "errors": ANY,
+            "app_label": "tests",
+            "original_opts": ANY,
+            "changelist_url": "/admin/tests/poll/",
+            "change_url": ANY,
+            "history_url": "/admin/tests/poll/1/history/",
+            "add": False,
+            "change": True,
+            "has_add_permission": admin.has_add_permission(request),
+            "has_change_permission": admin.has_change_permission(request, poll),
+            "has_delete_permission": admin.has_delete_permission(request, poll),
+            "has_file_field": True,
+            "has_absolute_url": False,
+            "form_url": "",
+            "opts": ANY,
+            "content_type_id": ANY,
+            "save_as": admin.save_as,
+            "save_on_top": admin.save_on_top,
+            "root_path": getattr(admin_site, "root_path", None),
+        }
+        context.update(admin_site.each_context(request))
+        mock_render.assert_called_once_with(
+            request, admin.object_history_form_template, context
+        )