Fix contrib/hstore_plperl to look through scalar refs.

Bring this transform function into sync with the policy established
by commit 3a382983d.

Also, fix it to make sure that what it drills down to is indeed a
hash, and not some other kind of Perl SV.  Previously, the test
cases added here provoked crashes.

Because of the crash hazard, back-patch to 9.5 where this module
was introduced.

Discussion: https://postgr.es/m/28336.1528393969@sss.pgh.pa.us

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index 25fc506c23f035b2e11f4f97d606617bd4cd968f..1ab09a94cda472fedc64044c9dcac3aca9452b99 100644 (file)
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -41,6 +41,25 @@ SELECT test2arr();
  {"\"a\"=>\"1\", \"b\"=>\"boo\", \"c\"=>NULL","\"d\"=>\"2\""}
 (1 row)
 
+-- check error cases
+CREATE OR REPLACE FUNCTION test2() RETURNS hstore
+LANGUAGE plperl
+TRANSFORM FOR TYPE hstore
+AS $$
+return 42;
+$$;
+SELECT test2();
+ERROR:  cannot transform non-hash Perl value to hstore
+CONTEXT:  PL/Perl function "test2"
+CREATE OR REPLACE FUNCTION test2() RETURNS hstore
+LANGUAGE plperl
+TRANSFORM FOR TYPE hstore
+AS $$
+return [1, 2];
+$$;
+SELECT test2();
+ERROR:  cannot transform non-hash Perl value to hstore
+CONTEXT:  PL/Perl function "test2"
 DROP FUNCTION test2();
 DROP FUNCTION test2arr();
 DROP EXTENSION hstore_plperl;

diff --git a/contrib/hstore_plperl/hstore_plperl.c b/contrib/hstore_plperl/hstore_plperl.c
index 6bc3bb37fc3ba356fb4b012512c690f971454f90..c09bd38d090e89863140ef0f8910cc2d90712094 100644 (file)
--- a/contrib/hstore_plperl/hstore_plperl.c
+++ b/contrib/hstore_plperl/hstore_plperl.c
@@ -101,7 +101,8 @@ Datum
 plperl_to_hstore(PG_FUNCTION_ARGS)
 {
        dTHX;
-       HV                 *hv = (HV *) SvRV((SV *) PG_GETARG_POINTER(0));
+       SV                 *in = (SV *) PG_GETARG_POINTER(0);
+       HV                 *hv;
        HE                 *he;
        int32           buflen;
        int32           i;
@@ -109,6 +110,17 @@ plperl_to_hstore(PG_FUNCTION_ARGS)
        HStore     *out;
        Pairs      *pairs;
 
+       /* Dereference references recursively. */
+       while (SvROK(in))
+               in = SvRV(in);
+
+       /* Now we must have a hash. */
+       if (SvTYPE(in) != SVt_PVHV)
+               ereport(ERROR,
+                               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                                (errmsg("cannot transform non-hash Perl value to hstore"))));
+       hv = (HV *) in;
+
        pcount = hv_iterinit(hv);
 
        pairs = palloc(pcount * sizeof(Pairs));

diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 9398aedfbbd5cd0178056c67bbf34546f1572f8e..ad1db7eae1799d1a7d1720d66b2c1c7da9e5df91 100644 (file)
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -31,6 +31,25 @@ $$;
 
 SELECT test2arr();
 
+-- check error cases
+CREATE OR REPLACE FUNCTION test2() RETURNS hstore
+LANGUAGE plperl
+TRANSFORM FOR TYPE hstore
+AS $$
+return 42;
+$$;
+
+SELECT test2();
+
+CREATE OR REPLACE FUNCTION test2() RETURNS hstore
+LANGUAGE plperl
+TRANSFORM FOR TYPE hstore
+AS $$
+return [1, 2];
+$$;
+
+SELECT test2();
+
 
 DROP FUNCTION test2();
 DROP FUNCTION test2arr();