protocol stripping problem

[rabernat]

I am trying to read a zarr store over plain http

This file exists:

curl http://s3.wasabisys.com/era5-single-reanalysis/.zmetadata

However, I can't access it from an HTTP filesystem

import fsspec
http_url = 'http://s3.wasabisys.com/era5-single-reanalysis'
mapper = fsspec.get_mapper(http_url)
mapper['.zmetadata']

MissingSchema: Invalid URL 's3.wasabisys.com/era5-single-reanalysis/.zmetadata': No schema supplied. Perhaps you meant http://s3.wasabisys.com/era5-single-reanalysis/.zmetadata?

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-16-690c397eba4f> in <module>
      2 http_url = 'http://s3.wasabisys.com/era5-single-reanalysis'
      3 mapper = fsspec.get_mapper(http_url)
----> 4 mapper['.zmetadata']

/srv/conda/envs/notebook/lib/python3.7/site-packages/fsspec/mapping.py in __getitem__(self, key, default)
     76             if default is not None:
     77                 return default
---> 78             raise KeyError(key)
     79         return result
     80 

KeyError: 's3.wasabisys.com/era5-single-reanalysis/.zmetadata'

According to @martindurant on gitter

fs.get_mapper() works as expected, but get_mapper does not, it strips the protocol instead of deferring to the class implementation of what to do with the protocol - this is only an issue for HTTP, I think.

--- a/fsspec/mapping.py
+++ b/fsspec/mapping.py
@@ -157,4 +157,4 @@ def get_mapper(url, check=False, create=False, **kwargs):
     cls = get_filesystem_class(protocol)
     fs = cls(**kwargs)
     # Removing protocol here - could defer to each open() on the backend
-    return FSMap(path, fs, check, create)
+    return FSMap(url, fs, check, create)

This feels like the sort of thing that should be covered by the test suite.

[rabernat]

Sorry this should have been an fsspec issue, not intake. Could someone transfer?