Teach pgrowlocks to check relkind before scanning

Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>

contrib/pgrowlocks/pgrowlocks.c

@@ -97,7 +97,19 @@ pgrowlocks(PG_FUNCTION_ARGS)
 
 		relname = PG_GETARG_TEXT_PP(0);
 		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-		rel = heap_openrv(relrv, AccessShareLock);
+		rel = relation_openrv(relrv, AccessShareLock);
+
+		if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("\"%s\" is a partitioned table",
+							RelationGetRelationName(rel)),
+					 errdetail("Partitioned tables do not contain rows.")));
+		else if (rel->rd_rel->relkind != RELKIND_RELATION)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("\"%s\" is not a table",
+							RelationGetRelationName(rel))));
 
 		/*
 		 * check permissions: must have SELECT on table or be in