From e0d23cd027a5a713a3ecda2748e5e9ddaddfde25 Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Sat, 4 May 2013 14:16:38 +0000
Subject: [PATCH] assertion error

---
 panda/src/pnmimage/pfmFile.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/panda/src/pnmimage/pfmFile.cxx b/panda/src/pnmimage/pfmFile.cxx
index 45587b1ff9..79bb4a12b1 100644
--- a/panda/src/pnmimage/pfmFile.cxx
+++ b/panda/src/pnmimage/pfmFile.cxx
@@ -931,6 +931,8 @@ set_no_data_nan(int num_channels) {
 ////////////////////////////////////////////////////////////////////
 void PfmFile::
 set_no_data_value(const LPoint4f &no_data_value) {
+  nassertv(is_valid());
+
   _has_no_data_value = true;
   _no_data_value = no_data_value;
   switch (_num_channels) {