From 132d511739481a1d48c6314e51dad404493b3dca Mon Sep 17 00:00:00 2001
From: Minh Vu <vuhoangminh97@gmail.com>
Date: Fri, 18 Sep 2026 23:27:50 +0200
Subject: [PATCH] Fix ArrayResultSet after-last cursor state

---
 CHANGELOG.md                                         |  2 ++
 .../com/clickhouse/jdbc/types/ArrayResultSet.java    |  5 +++--
 .../clickhouse/jdbc/types/ArrayResultSetTest.java    | 12 ++++++++++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 206ff3cc8..f9c2829e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -171,6 +171,8 @@
 
 ### Bug Fixes 
 
+- **[jdbc-v2]** Fixed `ArrayResultSet#next()` leaving the cursor before-first for empty arrays or on the last row for
+  non-empty arrays after exhaustion. The cursor now moves to the after-last state when `next()` returns `false`.
 - **[jdbc-v2]** Added the non-reserved keywords `AGGREGATE`, `BOUNDED`, `EXTEND`, `HANDLER`, `IDLE`, `PROTOCOL`,
   `RECENT`, `TIMEOUT` and `UNORDERED` (ClickHouse `26.8+`; `IDLE`, `TIMEOUT` and `RECENT` come from the multi-word
   keywords `IDLE TIMEOUT` and `RECENT SAMPLES`) to the list of keywords allowed in identifier positions. The server
diff --git a/jdbc-v2/src/main/java/com/clickhouse/jdbc/types/ArrayResultSet.java b/jdbc-v2/src/main/java/com/clickhouse/jdbc/types/ArrayResultSet.java
index 97da74a06..1f63ad3c8 100644
--- a/jdbc-v2/src/main/java/com/clickhouse/jdbc/types/ArrayResultSet.java
+++ b/jdbc-v2/src/main/java/com/clickhouse/jdbc/types/ArrayResultSet.java
@@ -98,7 +98,8 @@ private static ClickHouseColumn elementColumn(ClickHouseColumn column) {
 
     @Override
     public boolean next() throws SQLException {
-        if (pos + 1 >= length || length == 0) {
+        if (pos + 1 >= length) {
+            pos = length;
             return false;
         }
         pos++;
@@ -478,7 +479,7 @@ public boolean isAfterLast() throws SQLException {
 
     @Override
     public boolean isFirst() throws SQLException {
-        return pos == 0;
+        return length > 0 && pos == 0;
     }
 
     @Override
diff --git a/jdbc-v2/src/test/java/com/clickhouse/jdbc/types/ArrayResultSetTest.java b/jdbc-v2/src/test/java/com/clickhouse/jdbc/types/ArrayResultSetTest.java
index e4a417201..cbae5d169 100644
--- a/jdbc-v2/src/test/java/com/clickhouse/jdbc/types/ArrayResultSetTest.java
+++ b/jdbc-v2/src/test/java/com/clickhouse/jdbc/types/ArrayResultSetTest.java
@@ -308,10 +308,11 @@ void testEmptyArray() throws SQLException {
 
         assertFalse(rs.next());
 
-        Assert.assertTrue(rs.isBeforeFirst());
-        Assert.assertFalse(rs.isAfterLast());
+        Assert.assertFalse(rs.isBeforeFirst());
+        Assert.assertTrue(rs.isAfterLast());
         Assert.assertFalse(rs.isLast());
         Assert.assertFalse(rs.isFirst());
+        Assert.assertEquals(rs.getRow(), 0);
 
         Assert.assertThrows(SQLException.class, () -> rs.getString("col1"));
         Assert.assertThrows(SQLException.class, () -> rs.getObject("col1"));
@@ -573,7 +574,9 @@ void testNextEmptyArray() throws SQLException {
         ArrayResultSet rs = new ArrayResultSet(array, ClickHouseColumn.parse("v Array(Int32)").get(0));
 
         assertFalse(rs.next(), "next() should return false immediately for an empty array");
+        assertTrue(rs.isAfterLast(), "next() should move an empty array after-last");
         assertFalse(rs.next(), "next() should keep returning false on subsequent calls");
+        assertTrue(rs.isAfterLast(), "next() should keep the cursor after-last");
     }
 
     @Test
@@ -584,6 +587,11 @@ void testNextSingleElement() throws SQLException {
         assertTrue(rs.next());
         assertEquals(rs.getInt(2), 42);
         assertFalse(rs.next(), "next() should return false after the only element");
+        assertTrue(rs.isAfterLast());
+        assertFalse(rs.isLast());
+        assertEquals(rs.getRow(), 0);
+        assertTrue(rs.previous());
+        assertEquals(rs.getInt(2), 42);
     }
 
     @Test