Fixed #24455 -- Fixed crash in debug view with lazy objects

1 files changed, 9 insertions, 1 deletions

diff --git a/django/views/debug.py b/django/views/debug.py
index 15da162493..d0235f4bd4 100644
--- a/django/views/debug.py
+++ b/django/views/debug.py
@@ -186,7 +186,15 @@ class SafeExceptionReporterFilter(ExceptionReporterFilter):
                 return request.POST
 
     def cleanse_special_types(self, request, value):
-        if isinstance(value, HttpRequest):
+        try:
+            # If value is lazy or a complex object of another kind, this check
+            # might raise an exception. isinstance checks that lazy HttpRequests
+            # or MultiValueDicts will have a return value.
+            is_request = isinstance(value, HttpRequest)
+        except Exception as e:
+            return '{!r} while evaluating {!r}'.format(e, value)
+
+        if is_request:
             # Cleanse the request's POST parameters.
             value = self.get_request_repr(value)
         elif isinstance(value, MultiValueDict):