Fix platform and Perl-version dependencies in new jsonb_plperl code.

Testing SvTYPE() directly is more fraught with problems than one might
think, because depending on context Perl might be storing a scalar value
in one of several forms, eg both numeric and string values.  This resulted
in Perl-version-dependent buildfarm test failures.  Instead use the SvTYPE
test only to distinguish non-scalar cases (AV, HV, NULL).  Disambiguate
scalars by testing SvIOK, SvNOK, then SvPOK.  This creates a preference
order for how we will resolve cases where the value is available in more
than one form, which seems fine to me.

Furthermore, because we're now dealing directly with a "double" value
in the SvNOK case, we can get rid of an inadequate and unportable
string-comparison test for infinities, and use isinf() instead.
(We do need some additional #include and "-lm" infrastructure to use
that in a contrib module, per prior experiences.)

In passing, prevent the regression test results from depending on DROP
CASCADE order; I've not seen that malfunction, but it's trouble waiting
to happen.

Discussion: https://postgr.es/m/E1f3MMJ-0006bf-B0@gemulon.postgresql.org

1 files changed, 18 insertions, 8 deletions

diff --git a/contrib/jsonb_plperl/expected/jsonb_plperl.out b/contrib/jsonb_plperl/expected/jsonb_plperl.out
index 5bb5677f711..79d53e5e50f 100644
--- a/contrib/jsonb_plperl/expected/jsonb_plperl.out
+++ b/contrib/jsonb_plperl/expected/jsonb_plperl.out
@@ -39,15 +39,30 @@ SELECT testSVToJsonb();
  1
 (1 row)
 
+-- unsupported (for now)
 CREATE FUNCTION testRegexpToJsonb() RETURNS jsonb
 LANGUAGE plperl
 TRANSFORM FOR TYPE jsonb
 AS $$
-return ('1' =~ m(0\t2));
+my $a = qr/foo/;
+return ($a);
 $$;
 SELECT testRegexpToJsonb();
 ERROR:  cannot transform this Perl type to jsonb
 CONTEXT:  PL/Perl function "testregexptojsonb"
+-- this revealed a bug in the original implementation
+CREATE FUNCTION testRegexpResultToJsonb() RETURNS jsonb
+LANGUAGE plperl
+TRANSFORM FOR TYPE jsonb
+AS $$
+return ('1' =~ m(0\t2));
+$$;
+SELECT testRegexpResultToJsonb();
+ testregexpresulttojsonb 
+-------------------------
+ 0
+(1 row)
+
 CREATE FUNCTION roundtrip(val jsonb) RETURNS jsonb
 LANGUAGE plperl
 TRANSFORM FOR TYPE jsonb
@@ -201,11 +216,6 @@ SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}');
  {"1": {"2": [3, 4, 5]}, "2": 3}
 (1 row)
 
+\set VERBOSITY terse \\ -- suppress cascade details
 DROP EXTENSION plperl CASCADE;
-NOTICE:  drop cascades to 6 other objects
-DETAIL:  drop cascades to extension jsonb_plperl
-drop cascades to function testhvtojsonb()
-drop cascades to function testavtojsonb()
-drop cascades to function testsvtojsonb()
-drop cascades to function testregexptojsonb()
-drop cascades to function roundtrip(jsonb)
+NOTICE:  drop cascades to 7 other objects