From 8dce8dba85b17a57905605e291a2bb33f6d3c64d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus456@gmail.com>
Date: Thu, 7 Nov 2024 07:34:12 +0200
Subject: [PATCH] CONC-741: Check that MYSQL_STMT is not null

The code now again allows null MYSQL_STMT handles to be passed to
mysql_stmt_close(). Added a sanity check test case that should guard
against this happening in the future.
---
 libmariadb/mariadb_stmt.c  |  2 +-
 unittest/libmariadb/misc.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/libmariadb/mariadb_stmt.c b/libmariadb/mariadb_stmt.c
index cb37359e..215863ec 100644
--- a/libmariadb/mariadb_stmt.c
+++ b/libmariadb/mariadb_stmt.c
@@ -129,7 +129,7 @@ static my_bool madb_have_pending_results(MYSQL_STMT *stmt)
 {
   LIST *li_stmt;
 
-  if (!stmt->mysql)
+  if (!stmt || !stmt->mysql)
     return 0;
 
   li_stmt= stmt->mysql->stmts;
diff --git a/unittest/libmariadb/misc.c b/unittest/libmariadb/misc.c
index 136ffc62..628db2b9 100644
--- a/unittest/libmariadb/misc.c
+++ b/unittest/libmariadb/misc.c
@@ -1662,6 +1662,13 @@ static int test_disable_tls1_0(MYSQL *my __attribute__((unused)))
   return OK;
 }
 
+static int test_null_handles(MYSQL *)
+{
+  mysql_close(NULL);
+  mysql_stmt_close(NULL);
+  return OK;
+}
+
 
 struct my_tests_st my_tests[] = {
   {"test_disable_tls1_0", test_disable_tls1_0, TEST_CONNECTION_DEFAULT, 0, NULL, NULL},
@@ -1707,7 +1714,8 @@ struct my_tests_st my_tests[] = {
   {"test_ldi_path", test_ldi_path, TEST_CONNECTION_NEW, 0, NULL, NULL},
 #ifdef _WIN32
   {"test_conc44", test_conc44, TEST_CONNECTION_NEW, 0, NULL, NULL},
-#endif 
+#endif
+  {"test_null_handles", test_null_handles, TEST_CONNECTION_NONE, 0, NULL, NULL},
   {NULL, NULL, 0, 0, NULL, 0}
 };