From 0c1432ac7b4b0464351fb23196cf9070c05d0bd3 Mon Sep 17 00:00:00 2001 From: Sylvain Lebresne Date: Wed, 16 Sep 2015 13:17:18 +0200 Subject: [PATCH] Fix possible ClassCastException during paging In the case of DISTINCT query involving static columns and a IN on the partition key, it's possible to hit a ClassCastException when restoring the PagingState in SliceQueryPager because it assumes the cellname in said PagingState is a valid CellName even though it will be empty in that case. --- CHANGES.txt | 1 + .../apache/cassandra/service/pager/SliceQueryPager.java | 7 ++++--- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/CHANGES.txt b/CHANGES.txt index f6290500a0..deec093e6b 100644 --- a/CHANGES.txt +++ b/CHANGES.txt @@ -1,4 +1,5 @@ 2.1.10 + * Fix potential ClassCastException during paging (CASSANDRA-10352) * Prevent ALTER TYPE from creating circular references (CASSANDRA-10339) * Fix cache handling of 2i and base tables (CASSANDRA-10155, 10359) * Fix NPE in nodetool compactionhistory (CASSANDRA-9758) diff --git a/src/java/org/apache/cassandra/service/pager/SliceQueryPager.java b/src/java/org/apache/cassandra/service/pager/SliceQueryPager.java index 520fc34699..c8572d4749 100644 --- a/src/java/org/apache/cassandra/service/pager/SliceQueryPager.java +++ b/src/java/org/apache/cassandra/service/pager/SliceQueryPager.java @@ -59,9 +59,10 @@ public class SliceQueryPager extends AbstractQueryPager implements SinglePartiti if (state != null) { - // The only case where this could be a non-CellName Composite is if it's Composites.EMPTY, but that's not - // valid for PagingState.cellName, so we can safely cast to CellName. - lastReturned = (CellName) cfm.comparator.fromByteBuffer(state.cellName); + // The cellname can be empty if this is used in a MultiPartitionPager and we're supposed to start reading this row + // (because the previous page has exhausted the previous pager). See #10352 for details. + if (state.cellName.hasRemaining()) + lastReturned = (CellName) cfm.comparator.fromByteBuffer(state.cellName); restoreState(state.remaining, true); } }