Fix default grid handling

Author: alexgleith

apps/dc_tools/odc/apps/dc_tools/_stac.py

@@ -1,6 +1,7 @@
 """
 Tools for STAC to EO3 translation
 """
+
 import math
 import numpy
 from eodatasets3.serialise import from_doc
@@ -227,7 +228,10 @@ def _get_path(asset, force_relative=False):
         # If transform specified here in the asset it should override
         # the properties-specified transform.
         transform = asset.get("proj:transform") or proj_transform
-        grid = f"g{transform[0]:g}m"
+        if transform is not None:
+            grid = f"g{transform[0]:g}m"
+        else:
+            grid = default_grid
 
         # As per transform, shape here overrides properties
         shape = asset.get("proj:shape") or proj_shape