From 1b317cf2eded59e946234dbc729a42d7a5698114 Mon Sep 17 00:00:00 2001
From: Filipe Silva <filipe.silva@oracle.com>
Date: Fri, 6 Sep 2024 20:00:07 +0100
Subject: [PATCH] Fix for Bug#108415 (Bug#34579258), NullPointerException in
 AbstractQuery::stopQueryTimer.

Change-Id: I5a71825d70dd03dc0088ecaa71e743ac3e52ac8e
---
 CHANGES                                       |  3 ++
 .../java/com/mysql/cj/AbstractQuery.java      |  4 ++-
 .../regression/StatementRegressionTest.java   | 33 +++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index d197be6e8..e9c48e140 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,9 @@
 
 Version 9.1.0
 
+  - Fix for Bug#108415 (Bug#34579258), NullPointerException in AbstractQuery::stopQueryTimer.
+    Thanks to Anthony Milbourne for his contribution.
+
   - Fix for Bug#115265 (Bug#36843227), Second stored procedure call with cacheCallableStmts might fail.
 
   - Fix for Bug#36936407, PrepareCall method doesn't work as expected when DB name is involved.
diff --git a/src/main/core-impl/java/com/mysql/cj/AbstractQuery.java b/src/main/core-impl/java/com/mysql/cj/AbstractQuery.java
index a10ef5ee1..04a528932 100644
--- a/src/main/core-impl/java/com/mysql/cj/AbstractQuery.java
+++ b/src/main/core-impl/java/com/mysql/cj/AbstractQuery.java
@@ -235,7 +235,9 @@ public void stopQueryTimer(CancelQueryTask timeoutTask, boolean rethrowCancelRea
                 throw ExceptionFactory.createException(t.getMessage(), t);
             }
 
-            this.session.getCancelTimer().purge();
+            if (this.session != null) {
+                this.session.getCancelTimer().purge();
+            }
 
             if (checkCancelTimeout) {
                 checkCancelTimeout();
diff --git a/src/test/java/testsuite/regression/StatementRegressionTest.java b/src/test/java/testsuite/regression/StatementRegressionTest.java
index f3541255e..c679c7257 100644
--- a/src/test/java/testsuite/regression/StatementRegressionTest.java
+++ b/src/test/java/testsuite/regression/StatementRegressionTest.java
@@ -13796,4 +13796,37 @@ public void testBug112790() throws Exception {
         assertThrows(SQLException.class, this.stmt::getGeneratedKeys);
     }
 
+    /**
+     * Tests fix for Bug#108415 (Bug#34579258), NullPointerException in AbstractQuery::stopQueryTimer.
+     *
+     * @throws Exception
+     */
+    @Test
+    void testBug108415() throws Exception {
+        Connection testConn = getNewConnection();
+        final long sessionToKill = ((JdbcConnection) testConn).getId();
+
+        ExecutorService execServ = Executors.newSingleThreadExecutor();
+        execServ.execute(() -> {
+            try {
+                TimeUnit.SECONDS.sleep(2);
+            } catch (InterruptedException e) {
+            }
+            try {
+                System.out.println("Killing process id " + sessionToKill);
+                this.stmt.execute("KILL " + sessionToKill);
+            } catch (SQLException e) {
+            }
+        });
+
+        Statement testStmt = testConn.createStatement();
+        testStmt.setQueryTimeout(15);
+        assertThrows(SQLException.class, () -> {
+            testStmt.executeQuery("SELECT SLEEP(15)");
+            return null;
+        });
+
+        execServ.shutdown();
+    }
+
 }