df.reset_index fails with tz-aware column (similar to #7533)

[rockg]

The below fails with "ValueError: Length of values does not match length of index". However, without the timezone it works fine. It's because of pandas/core/frame.py _maybe_casted_values index.tz is not None clause. Something similar was done in #7533 but the added examples don't test this case. cc @sinhrks

import pandas as pd
import numpy as np

dts     =   pd.date_range('1/1/2012', '1/31/2012', freq='D', tz='US/Eastern')
columns =   [1, 2, 3]
data    =   np.random.randn(31, 3)

frame   =   pd.DataFrame(data, columns=columns, index=dts)
frame   =   frame.stack()
frame.reset_index()

[jreback]

in master?

[rockg]

At least in .14 Can't check master until later, but the suspect code is the same between .14 and master.

[jreback]

#7802 was just merged in to fix something similar

cc @sinhrks

[jreback]

works in master (might be broken in 0.14.1 as well).

cc @sinhrks

if these tests are different, pls add them

closing as already fixed