From f3663b8d2e8b1f9d035fd612865379aed23730bd Mon Sep 17 00:00:00 2001
From: mrdudz <mrdudz@users.noreply.github.com>
Date: Wed, 28 Apr 2021 14:21:48 +0200
Subject: [PATCH] added test for issue #1461

---
 test/val/pr1461.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 test/val/pr1461.c

diff --git a/test/val/pr1461.c b/test/val/pr1461.c
new file mode 100644
index 000000000..dae6b2999
--- /dev/null
+++ b/test/val/pr1461.c
@@ -0,0 +1,53 @@
+
+/* pr#1461 Fixed pointer subtraction in certain very rare cases */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+static int err = 0;
+
+static int a[1], *p;
+static unsigned int i1, i2;
+
+int test1(void)
+{
+    p = a - (int)a;
+    printf("a: %p - (int)a: 0x%x = p: %p\n", a, (int)a, p);
+    printf("i1: 0x%x - i2: 0x%x = p: %p\n", i1, i2, i1 - i2);
+    if ((int)p != (i1 - i2)) {
+        printf("-> failed\n");
+        return 1;
+    }
+    return 0;
+}
+
+int test2(void)
+{
+    p = p - (int)a;
+    printf("p: %p - (int)a: 0x%x = p: %p\n", p, (int)a, p);
+    printf("p: %p - i2: 0x%x = p: %p\n", p, i2, 0x1234 - i2);
+    if ((int)p != (0x1234 - i2)) {
+        printf("-> failed\n");
+        return 1;
+    }
+    return 0;
+}
+
+int main(void)
+{
+    a[0] = 0x4711;
+    i1 = (int)a;
+    i2 = i1 << 1;
+
+    p = (int*)0x1234;
+    printf("p: %p &a[0]: %p a: %p (int)a: 0x%x i1: 0x%x i2: 0x%x\n", p, &a[0], a, (int)a, i1, i2);
+
+    err += test1();
+
+    p = (int*)0x1234;
+    printf("p: %p &a[0]: %p a: %p (int)a: 0x%x i1: 0x%x i2: 0x%x\n", p, &a[0], a, (int)a, i1, i2);
+
+    err += test2();
+
+    return err;
+}