Testing convert_to(..., 'ISO-8859-1') fails if there isn't a conversion
function available from the database encoding to ISO-8859-1. This has
been broken since day one, but the breakage was hidden by
pg_do_encoding_conversion's failure to complain, up till commit
49c817eab7.
Since the data being converted in this test is plain ASCII, no actual
conversion need happen (and if it did, it would prove little about citext
anyway). So that we still have some code coverage of the convert() family
of functions, let's switch to using convert_from, with SQL_ASCII as the
specified source encoding. Per buildfarm.
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.