Handle iteration errors during frame traversal (#239)

* Handle iteration errors during frame traversal

* Fixes as suggested by @untitaker

* Add explanatory comments

* Replace deprecated `render_to_response` with `render`

Author: leotrubach

sentry_sdk/utils.py

@@ -310,7 +310,9 @@ def safe_repr(value):
 def object_to_json(obj):
     def _walk(obj, depth):
         if depth < 4:
-            if isinstance(obj, Sequence) and not isinstance(obj, (bytes, text_type)):
+            if isinstance(obj, (list, tuple)):
+                # It is not safe to iterate over another sequence types as this may raise errors or
+                # bring undesired side-effects (e.g. Django querysets are executed during iteration)
                 return [_walk(x, depth + 1) for x in obj]
             if isinstance(obj, Mapping):
                 return {safe_str(k): _walk(v, depth + 1) for k, v in obj.items()}

tests/integrations/django/myapp/views.py

@@ -1,7 +1,7 @@
 from django.contrib.auth import login
 from django.contrib.auth.models import User
 from django.http import HttpResponse, HttpResponseServerError, HttpResponseNotFound
-from django.shortcuts import render_to_response
+from django.shortcuts import render
 from django.views.generic import ListView
 
 import sentry_sdk
@@ -45,5 +45,5 @@ def handler404(*args, **kwargs):
     return HttpResponseNotFound("404")
 
 
-def template_exc(*args, **kwargs):
-    return render_to_response("error.html")
+def template_exc(request, *args, **kwargs):
+    return render(request, "error.html")