If numpy has a problem reshaping data, issue a warning instead of crashing

Addresses #1038

overviewer_core/world.py

@@ -414,6 +414,7 @@ class RegionSet(object):
 
             # Turn the skylight array into a 16x16x16 matrix. The array comes
             # packed 2 elements per byte, so we need to expand it.
+            try:
                 skylight = numpy.frombuffer(section['SkyLight'], dtype=numpy.uint8)
                 skylight = skylight.reshape((16,16,8))
                 skylight_expanded = numpy.empty((16,16,16), dtype=numpy.uint8)
@@ -439,6 +440,13 @@ class RegionSet(object):
                 data_expanded[:,:,1::2] = (data & 0xF0) >> 4
                 del data
                 section['Data'] = data_expanded
+            except ValueError:
+                # iv'e seen at least 1 case where numpy raises a value error during the reshapes.  i'm not
+                # sure what's going on here, but let's treat this as a corrupt chunk error
+                logging.warning("There was a problem reading chunk %d,%d.  It might be corrupt.  I am giving up and will not render this particular chunk.", x, z)
+
+                logging.debug("Full traceback:", exc_info=1)
+                raise nbt.CorruptChunkError()
         
         return chunk_data