Add a test for zero-sized writes through null

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/ui/precondition-checks/zero-size-null.rs b/tests/ui/precondition-checks/zero-size-null.rs
new file mode 100644
index 00000000000..43a81175f94
--- /dev/null
+++ b/tests/ui/precondition-checks/zero-size-null.rs
@@ -0,0 +1,21 @@
+// Test that none of the precondition checks panic on zero-sized reads or writes through null.
+
+//@ run-pass
+//@ compile-flags: -Zmir-opt-level=0 -Copt-level=0 -Cdebug-assertions=yes
+
+use std::ptr;
+
+fn main() {
+    unsafe {
+        ptr::copy_nonoverlapping::<u8>(ptr::null(), ptr::null_mut(), 0);
+        ptr::copy_nonoverlapping::<()>(ptr::null(), ptr::null_mut(), 123);
+        ptr::copy::<u8>(ptr::null(), ptr::null_mut(), 0);
+        ptr::copy::<()>(ptr::null(), ptr::null_mut(), 123);
+        ptr::swap::<()>(ptr::null_mut(), ptr::null_mut());
+        ptr::replace::<()>(ptr::null_mut(), ());
+        ptr::read::<()>(ptr::null());
+        ptr::write::<()>(ptr::null_mut(), ());
+        ptr::read_volatile::<()>(ptr::null());
+        ptr::write_volatile::<()>(ptr::null_mut(), ());
+    }
+}