Fix failure with textual partition hash keys.

Commit 5e1963fb7 overlooked two places in partbounds.c that now
need to pass a collation identifier to the hash functions for
a partition key column.

Amit Langote, per report from Jesper Pedersen

Discussion: https://postgr.es/m/a620f85a-42ab-e0f3-3337-b04b97e2e2f5@redhat.com

src/backend/partitioning/partbounds.c

@@ -2742,7 +2742,8 @@ compute_partition_hash_value(int partnatts, FmgrInfo *partsupfunc, Oid *partcoll
 			 * datatype-specific hash functions of each partition key
 			 * attribute.
 			 */
-			hash = FunctionCall2Coll(&partsupfunc[i], partcollation[i], values[i], seed);
+			hash = FunctionCall2Coll(&partsupfunc[i], partcollation[i],
+									 values[i], seed);
 
 			/* Form a single 64-bit hash value */
 			rowHash = hash_combine64(rowHash, DatumGetUInt64(hash));
@@ -2777,7 +2778,8 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 		int16		variadic_typlen;
 		bool		variadic_typbyval;
 		char		variadic_typalign;
-		FmgrInfo	partsupfunc[PARTITION_MAX_KEYS];
+		Oid			partcollid[PARTITION_MAX_KEYS];
+		FmgrInfo	partsupfunc[FLEXIBLE_ARRAY_MEMBER];
 	} ColumnsHashData;
 	Oid			parentId;
 	int			modulus;
@@ -2850,6 +2852,8 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 			my_extra = (ColumnsHashData *) fcinfo->flinfo->fn_extra;
 			my_extra->relid = parentId;
 			my_extra->nkeys = key->partnatts;
+			memcpy(my_extra->partcollid, key->partcollation,
+				   key->partnatts * sizeof(Oid));
 
 			/* check argument types and save fmgr_infos */
 			for (j = 0; j < key->partnatts; ++j)
@@ -2866,7 +2870,6 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 							   &key->partsupfunc[j],
 							   fcinfo->flinfo->fn_mcxt);
 			}
-
 		}
 		else
 		{
@@ -2885,6 +2888,7 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 								 &my_extra->variadic_typlen,
 								 &my_extra->variadic_typbyval,
 								 &my_extra->variadic_typalign);
+			my_extra->partcollid[0] = key->partcollation[0];
 
 			/* check argument types */
 			for (j = 0; j < key->partnatts; ++j)
@@ -2926,11 +2930,10 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 			if (PG_ARGISNULL(argno))
 				continue;
 
-			Assert(OidIsValid(my_extra->partsupfunc[i].fn_oid));
-
-			hash = FunctionCall2(&my_extra->partsupfunc[i],
-								 PG_GETARG_DATUM(argno),
-								 seed);
+			hash = FunctionCall2Coll(&my_extra->partsupfunc[i],
+									 my_extra->partcollid[i],
+									 PG_GETARG_DATUM(argno),
+									 seed);
 
 			/* Form a single 64-bit hash value */
 			rowHash = hash_combine64(rowHash, DatumGetUInt64(hash));
@@ -2965,11 +2968,10 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 			if (isnull[i])
 				continue;
 
-			Assert(OidIsValid(my_extra->partsupfunc[0].fn_oid));
-
-			hash = FunctionCall2(&my_extra->partsupfunc[0],
-								 datum[i],
-								 seed);
+			hash = FunctionCall2Coll(&my_extra->partsupfunc[0],
+									 my_extra->partcollid[0],
+									 datum[i],
+									 seed);
 
 			/* Form a single 64-bit hash value */
 			rowHash = hash_combine64(rowHash, DatumGetUInt64(hash));

src/test/regress/expected/hash_part.out

@@ -99,6 +99,20 @@ ERROR:  number of partitioning columns (2) does not match number of partition ke
 SELECT satisfies_hash_partition('mcinthash'::regclass, 4, 0,
 								variadic array[now(), now()]);
 ERROR:  column 1 of the partition key has type "integer", but supplied value is of type "timestamp with time zone"
+-- check satisfies_hash_partition passes correct collation
+create table text_hashp (a text) partition by hash (a);
+create table text_hashp0 partition of text_hashp for values with (modulus 2, remainder 0);
+create table text_hashp1 partition of text_hashp for values with (modulus 2, remainder 1);
+-- The result here should always be true, because 'xxx' must belong to
+-- one of the two defined partitions
+select satisfies_hash_partition('text_hashp'::regclass, 2, 0, 'xxx'::text) OR
+	   satisfies_hash_partition('text_hashp'::regclass, 2, 1, 'xxx'::text) AS satisfies;
+ satisfies 
+-----------
+ t
+(1 row)
+
 -- cleanup
 DROP TABLE mchash;
 DROP TABLE mcinthash;
+DROP TABLE text_hashp;

src/test/regress/sql/hash_part.sql

@@ -75,6 +75,16 @@ SELECT satisfies_hash_partition('mcinthash'::regclass, 4, 0,
 SELECT satisfies_hash_partition('mcinthash'::regclass, 4, 0,
 								variadic array[now(), now()]);
 
+-- check satisfies_hash_partition passes correct collation
+create table text_hashp (a text) partition by hash (a);
+create table text_hashp0 partition of text_hashp for values with (modulus 2, remainder 0);
+create table text_hashp1 partition of text_hashp for values with (modulus 2, remainder 1);
+-- The result here should always be true, because 'xxx' must belong to
+-- one of the two defined partitions
+select satisfies_hash_partition('text_hashp'::regclass, 2, 0, 'xxx'::text) OR
+	   satisfies_hash_partition('text_hashp'::regclass, 2, 1, 'xxx'::text) AS satisfies;
+
 -- cleanup
 DROP TABLE mchash;
 DROP TABLE mcinthash;
+DROP TABLE text_hashp;