[INSTRM-383] String keywords not always escaped in a way which can be predictably unescaped.

Tue, 12 Jun 2018 16:12:28 +0000

Transferring headers from gen2Actor has uncovered an old mistake. The symptom is that only one of:

  header1 = r"""OBSERVER = '"Name, Other Name"' / double-quoted"""
  header2 = r"""OBSERVER = 'Name' / Not double-quoted"""

can make it through from one of:

  cmd.inform('header=%s' % (header))
  cmd.inform('header=%s' % (repr(header)))

to an identical string at the listener:

  header = self.actor.models['gen2']['header'].values[0]

I believe that the issue boils down to a pre-SDSS choice not to internally use repr to encode a string (because it does too much and makes strings ugly), but not fixing the decoding when SDSS switched to the opscore parser. Basically:

from opscore.utility.qstr import qstr

s = "any horrible thing"

# OK
eval(repr(s) == s # By definition

# Not OK
eval(qstr(repr(s)) != s # double-quotes get an additional escaping.
qstr(s) != s   # Of course not.

PFS-JIRA

[INSTRM-383] String keywords not always escaped in a way which can be predictably unescaped.