From b275ff345f49ab1c927e9e01a831c5e205071c1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20S=C3=A1nchez=20Parra?= <javsanpar@riseup.net>
Date: Thu, 2 Feb 2023 15:14:37 +0100
Subject: [PATCH] Fix read-after-free in test multiple_prepared_statements-t

The test closes half the MySQL connections and later tries to close all
the connections, even the ones that have been closed before.
---
 test/tap/tests/multiple_prepared_statements-t.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/tap/tests/multiple_prepared_statements-t.cpp b/test/tap/tests/multiple_prepared_statements-t.cpp
index caf8e258d..8a4560437 100644
--- a/test/tap/tests/multiple_prepared_statements-t.cpp
+++ b/test/tap/tests/multiple_prepared_statements-t.cpp
@@ -269,7 +269,9 @@ int main(int argc, char** argv) {
 		}
 	}
 
-	for (int i=0; i<NCONNS; i++) {
+	// Half of the connections were freed earlier. We only iterate the other
+	// half that has not been freed.
+	for (int i=1; i<NCONNS; i+=2) {
 		mysql_close(conns[i]);
 	}