return None rather than raise exception if headers are missing

GeminiDRSoftware · Jul 20, 2023 · fd289c9 · fd289c9
1 parent 1220c4d
commit fd289c9
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/gemini_instruments/gnirs/adclass.py b/gemini_instruments/gnirs/adclass.py
@@ -308,6 +308,8 @@ def disperser(self, stripID=False, pretty=False):
 
         grating = self._grating(stripID=stripID, pretty=pretty)
         prism = self._prism(stripID=stripID, pretty=pretty)
+        if prism is None or grating is None:
+            return None
         if prism.startswith('MIR'):
             return grating