1 files changed, 13 insertions, 0 deletions
diff --git a/test/underflow.c b/test/underflow.c
new file mode 100644
index 0000000..f23aa6d
--- /dev/null
+++ b/test/underflow.c
@@ -0,0 +1,13 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdio.h>
+#include <unistd.h>
+#include "mapalloc.h"
+
+int main(void)
+{
+	char *ptr = map_malloc(1);
+	long pagesize = sysconf(_SC_PAGESIZE);
+	printf("ptr: %p, pagesize %ld\n", ptr, pagesize);
+	ptr[-1] = '\0';
+	printf("shouldn't get here\n");
+}