docs: def post_comment(request, next=None, using=None):
      """
      Post a comment.
  
      HTTP POST is required.
      """
      # Fill out some initial data fields from an authenticated user, if present
      data = request.POST.copy()
      if request.user.is_authenticated:
          data["user"] = request.user
      else:
          return CommentPostBadRequest("You must be logged in to comment")
  
      # Look up the object we're trying to comment about
      ctype = data.get("content_type")
      object_pk = data.get("object_pk")
      if ctype is None or object_pk is None:
          return CommentPostBadRequest("Missing content_type or object_pk field.")
      try:
          model = models.get_model(*ctype.split(".", 1))
          target = model._default_manager.using(using).get(pk=object_pk)
      except TypeError:
          return CommentPostBadRequest(
              "Invalid content_type value: %r" % escape(ctype))
      except AttributeError:
          return CommentPostBadRequest(
              "The given content-type %r does not resolve to a valid model." % \
                  escape(ctype))
      except ObjectDoesNotExist:
          return CommentPostBadRequest(
              "No object matching content-type %r and object PK %r exists." % \
                  (escape(ctype), escape(object_pk)))
      except (ValueError, ValidationError) as e:
          return CommentPostBadRequest(
              "Attempting go get content-type %r and object PK %r exists raised %s" % \
                  (escape(ctype), escape(object_pk), e.__class__.__name__))
  
      # Construct the comment form
      form = comments.get_form()(target, data=data)
  
      # Check security information
      if form.security_errors():
          return CommentPostBadRequest(
              "The comment form failed security verification: %s" % \
                  escape(str(form.security_errors())))
  
      # Check for next
      if not next:
          next = data.get("next")
  
      # If there are errors show the comment
      if form.errors:
          template_list = [
              "comments/%s/%s/form.html" % (model._meta.app_label, model._meta.module_name),
              "comments/%s/form.html" % model._meta.app_label,
              "comments/form.html",
          ]
          return render_to_response(
              template_list, {
                  "comment": form.data.get("comment", ""),
                  "form": form,
                  "next": data.get("next", next),
              },
              RequestContext(request, {})
          )
  
      # Otherwise create the comment
      comment = form.get_comment_object()
      comment.ip_address = request.META.get("REMOTE_ADDR", None)
      if request.user.is_authenticated:
          comment.user = request.user
  
      # Signal that the comment is about to be saved
      responses = signals.comment_will_be_posted.send(
          sender=comment.__class__,
          comment=comment,
          request=request
      )
  
      for (receiver, response) in responses:
          if response == False:
              return CommentPostBadRequest(
                  "comment_will_be_posted receiver %r killed the comment" % receiver.__name__)
  
      # Save the comment and signal that it was saved
      comment.save()
      signals.comment_was_posted.send(
          sender=comment.__class__,
          comment=comment,
          request=request
      )
      messages.success(request, 'Your comment was saved.')
      return redirect(next)