From e8a3134492d78f73d7b70cd40fc48c17cad6dc63 Mon Sep 17 00:00:00 2001
From: Jean-Romain Garnier <jean-romain.garnier@supelec.fr>
Date: Thu, 23 Apr 2020 20:50:31 +0200
Subject: [PATCH] Better handle deleted objects in detailed history view

---
 logs/models.py | 29 +++++++++++++++++++++++------
 logs/views.py  | 21 ++++++++-------------
 2 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/logs/models.py b/logs/models.py
index 4b5b9569..d7f9e270 100644
--- a/logs/models.py
+++ b/logs/models.py
@@ -308,6 +308,10 @@ class History:
         for version in interface_versions:
             self._add_revision(version)
 
+        # Return None if interface_versions was empty
+        if self._last_version is None:
+            return None
+
         return self.events[::-1]
 
     def _compute_diff(self, v1, v2, ignoring=[]):
@@ -444,13 +448,26 @@ class UserHistory(History):
         """
         self.events = []
 
-        # Find whether this is a Club or an Adherent
-        try:
-            obj = Adherent.objects.get(user_ptr_id=user_id)
-        except Adherent.DoesNotExist:
-            obj = Club.objects.get(user_ptr_id=user_id)
+        # Try to find an Adherent object
+        adherents = filter(
+            lambda x: x.field_dict["user_ptr_id"] == user_id,
+            Version.objects.get_for_model(Adherent)
+        )
+        obj = next(adherents, None)
 
-        # Add as "related" histories the list of Machine objects
+        # Fallback on a Club
+        if obj is None:
+            clubs = filter(
+                lambda x: x.field_dict["user_ptr_id"] == user_id,
+                Version.objects.get_for_model(Club)
+            )
+            obj = next(clubs, None)
+
+        # If nothing was found, abort
+        if obj is None:
+            return None
+
+        # Add in "related" elements the list of Machine objects
         # that were once owned by this user
         self.related = filter(
             lambda x: x.field_dict["user_id"] == user_id,
diff --git a/logs/views.py b/logs/views.py
index c0f3d6e9..981d3d00 100644
--- a/logs/views.py
+++ b/logs/views.py
@@ -518,7 +518,6 @@ def get_history_object(request, model, object_name, object_id, allow_deleted=Fal
     """Get the objet of type model with the given object_id
     Handles permissions and DoesNotExist errors
     """
-    instance = None
     is_deleted = False
 
     try:
@@ -526,20 +525,9 @@ def get_history_object(request, model, object_name, object_id, allow_deleted=Fal
         kwargs = {object_name_id: object_id}
         instance = model.get_instance(**kwargs)
     except model.DoesNotExist:
-        pass
-
-    if instance is None and allow_deleted:
-        # Try to find an instance among the Version objects
         is_deleted = True
-        versions = filter(
-            lambda x: x.field_dict["id"] == object_id,
-            Version.objects.get_for_model(model)
-        )
-        versions = list(versions)
-        if len(versions):
-            instance = versions[0]
 
-    if instance is None:
+    if is_deleted and not allow_deleted:
         messages.error(request, _("Nonexistent entry."))
         return False, redirect(
             reverse("users:profil", kwargs={"userid": str(request.user.id)})
@@ -593,6 +581,13 @@ def detailed_history(request, object_name, object_id):
         max_result
     )
 
+    # Events is None if object wasn't found
+    if events is None:
+        messages.error(request, _("Nonexistent entry."))
+        return redirect(
+            reverse("users:profil", kwargs={"userid": str(request.user.id)})
+        )
+
     return render(
         request,
         "logs/detailed_history.html",