json with multiindex and orient=split, fail to read what has been written

[mchevann]

Summary

Attempting to read a JSON file that has been written with orient="split" and a multi index is failing.
Pandas '0.17.0' on Python 3.5.0.

Observations

It works with orient=columns
It works when there is no multiindex
The output seems ok, the issue is probably on the decoding

Test case

import pandas as pd
df=pd.DataFrame([[1,2,3,4],[3,4,5,6],[7,8,9,10]],columns=["a","b","c","d"]).groupby(["a","b"]).sum()
df.to_json("t.json",orient="split")
pd.read_json("t.json",orient="split")

Error message

Traceback (most recent call last):

File "", line 1, in
pd.read_json("t.json",orient="split")

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\json.py", line 210, in read_json
date_unit).parse()

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\json.py", line 278, in parse
self._parse_no_numpy()

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\json.py", line 502, in _parse_no_numpy
self.obj = DataFrame(dtype=None, **decoded)

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 277, in init
dtype=dtype)

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 5102, in _arrays_to_mgr
return create_block_manager_from_arrays(arrays, arr_names, axes)

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py", line 3805, in create_block_manager_from_arrays
construction_error(len(arrays), arrays[0].shape, axes, e)

File "C:\Users\mchevann\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py", line 3771, in construction_error
passed,implied))

ValueError: Shape of passed values is (2, 3), indices imply (2, 2)

[jreback]

this is a dupe of #4889