fitsio can read a header with a HIERARCH card, but then fails to write it out again

[dstndstn]

Hi,

To reproduce:

wget https://portal.nersc.gov/project/cosmo/temp/dstn/c4d_160812_060140_oow_z_ls9.fits.fz
python -c "import fitsio; print(fitsio.__version__); h = fitsio.read_header('c4d_160812_060140_oow_z_ls9.fits.fz', ext=1); print(h); fitsio.write('x.fits', None, header=h, clobber=True)"

This is with fitsio 1.1.8.

This file has a pretty weird card in the extension header,

DECALS_DR9_954a179-z-20160812T055930_oi[S29,noinherit][2046,4094][real]: DECaLS_

which then gets read in / printed by fitsio as

HIERARCH DECALS_DR9_954a179-z-20160812T055930_oi[S29,noinherit][2046,4094][real]

but fitsio fails when trying to write out that header card:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python3.9/site-packages/fitsio/fitslib.py", line 396, in write
    fits.write(
  File "/usr/local/lib/python3.9/site-packages/fitsio/fitslib.py", line 693, in write
    self.write_image(data, extname=extname, extver=extver,
  File "/usr/local/lib/python3.9/site-packages/fitsio/fitslib.py", line 795, in write_image
    self[-1].write_keys(header)
  File "/usr/local/lib/python3.9/site-packages/fitsio/hdu/base.py", line 344, in write_keys
    self.write_key(name, value, comment=comment)
  File "/usr/local/lib/python3.9/site-packages/fitsio/hdu/base.py", line 240, in write_key
    self._FITS.write_undefined_key(self._ext+1,
OSError: FITSIO status = 207: illegal character in keyword
The following keyword is too long to fit on a card:
DECALS_DR9_954A179-Z-20160812T055930_OI[S29,NOINHERIT][2046,4094][REAL]:

[esheldon]

Any ideas what is going on here?

[dstndstn]

No, I didn't dig at all -- it's a pretty weird header card, I think put in due to a bug in the CP. I'm not sure whether it's actually illegal or not.

I guess I must have worked around this in some way or another, because it's not holding anything up :)

[dstndstn]

Just ran into this again - I think it's the "[" and "]" characters in the key that is causing the trouble.

OSError: FITSIO status = 207: illegal character in keyword
The following keyword is too long to fit on a card:
DES17B_20171212_905E4E2-G-20171215T052333_OI[N1,NOINHERIT][2046,4094][REAL

[dstndstn]

(again: these are probably-illegal header cards, so not really fitsio's fault for bombing! It's just funny that it can read them in but then not write them out. That is pretty consistent with the FITS philosophy, though - liberal on read, strict on write!)