diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 57453a7..9bad121 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -349,7 +349,7 @@ SetSequence(Oid seq_relid, int64 value)
 	/* open and lock sequence */
 	init_sequence(seq_relid, &elm, &seqrel);
 
-	/* lock page' buffer and read tuple */
+	/* lock page buffer and read tuple */
 	seq = read_seq_tuple(seqrel, &buf, &seqdatatuple, NULL);
 
 	/* check the comment above nextval_internal()'s equivalent call. */
@@ -397,8 +397,10 @@ SetSequence(Oid seq_relid, int64 value)
 
 	UnlockReleaseBuffer(buf);
 
-	/* Clear local cache so that we don't think we have cached numbers */
-	/* Note that we do not change the currval() state */
+	/*
+	 * Clear local cache so that we don't think we have cached numbers.
+	 * Note that we do not change the currval() state.
+	 */
 	elm->cached = elm->last;
 
 	relation_close(seqrel, NoLock);
@@ -1275,8 +1277,9 @@ read_seq_tuple(Relation rel, Buffer *buf, HeapTuple seqdatatuple,
 			 RelationGetRelationName(rel), sm->magic);
 
 	/*
-	 * If the caller requested it, set the page LSN. This allows deciding
-	 * which sequence changes are before/after the returned sequence state.
+	 * If the caller requested it, return the page LSN. This allows the
+	 * caller to determine which sequence changes are before/after the
+	 * returned sequence state.
 	 */
 	if (lsn)
 		*lsn = PageGetLSN(page);
@@ -1912,7 +1915,7 @@ pg_sequence_last_value(PG_FUNCTION_ARGS)
 Datum
 pg_sequence_state(PG_FUNCTION_ARGS)
 {
-	Oid			relid = PG_GETARG_OID(0);
+	Oid			seq_relid = PG_GETARG_OID(0);
 	SeqTable	elm;
 	Relation	seqrel;
 	Buffer		buf;
@@ -1920,21 +1923,21 @@ pg_sequence_state(PG_FUNCTION_ARGS)
 	Form_pg_sequence_data seq;
 	Datum		result;
 
+	XLogRecPtr	lsn;
 	int64		last_value;
 	int64		log_cnt;
 	bool		is_called;
-	XLogRecPtr	lsn;
 
 	TupleDesc	tupdesc;
 	HeapTuple	tuple;
 	Datum		values[4];
-	bool		nulls[4];
+	bool		nulls[4] = {false, false, false, false};
 
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "return type must be a row type");
 
 	/* open and lock sequence */
-	init_sequence(relid, &elm, &seqrel);
+	init_sequence(seq_relid, &elm, &seqrel);
 
 	if (pg_class_aclcheck(elm->relid, GetUserId(),
 						  ACL_SELECT | ACL_USAGE) != ACLCHECK_OK)
@@ -1957,8 +1960,6 @@ pg_sequence_state(PG_FUNCTION_ARGS)
 	values[2] = Int64GetDatum(log_cnt);
 	values[3] = BoolGetDatum(is_called);
 
-	memset(nulls, 0, sizeof(nulls));
-
 	tuple = heap_form_tuple(tupdesc, values, nulls);
 	result = HeapTupleGetDatum(tuple);