Before 9.1, PL/Python functions returning composite types could return
a string and it would be parsed using record_in. The 9.1 changes made
PL/Python only expect dictionaries, tuples, or objects supporting
getattr as output of composite functions, resulting in a regression
and a confusing error message, as the strings were interpreted as
sequences and the code for transforming lists to database tuples was
used. Fix this by treating strings separately as before, before
checking for the other types.
The reason why it's important to support string to database tuple
conversion is that trigger functions on tables with composite columns
get the composite row passed in as a string (from record_out).
Without supporting converting this back using record_in, this makes it
impossible to implement pass-through behavior for these columns, as
PL/Python no longer accepts strings for composite values.
A better solution would be to fix the code that transforms composite
inputs into Python objects to produce dictionaries that would then be
correctly interpreted by the Python->PostgreSQL counterpart code. But
that would be too invasive to backpatch to 9.1, and it is too late in
the 9.2 cycle to attempt it. It should be revisited in the future,
though.
Reported as bug #6559 by Kirill Simonov.
Jan Urbański
Dropped columns within a composite type were not handled correctly.
Also, we did not check for whether a composite result type had changed
since we cached the information about it.
Jan Urbański, per a bug report from Jean-Baptiste Quenot
This allows functions with multiple OUT parameters returning both one
or multiple records (RECORD or SETOF RECORD).
Jan Urbański, reviewed by Hitoshi Harada
of the previous monolithic setup-create-run sequence, that was apparently
inherited from a previous test infrastructure, but makes working with the
tests and adding new ones weird.
