Auto merge of #18317 - lnicola:sync-from-rust, r=Veykril

minor: sync from downstream

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/ui/precondition-checks/write_bytes.rs b/tests/ui/precondition-checks/write_bytes.rs
new file mode 100644
index 00000000000..3f64be9d1ee
--- /dev/null
+++ b/tests/ui/precondition-checks/write_bytes.rs
@@ -0,0 +1,18 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: ptr::write requires
+//@ revisions: null misaligned
+//@ ignore-test
+
+use std::ptr;
+
+fn main() {
+    let mut dst = [0u16; 2];
+    let mut dst = dst.as_mut_ptr();
+    unsafe {
+        #[cfg(null)]
+        ptr::write_bytes(ptr::null_mut::<u8>(), 1u8, 2);
+        #[cfg(misaligned)]
+        ptr::write_bytes(dst.byte_add(1), 1u8, 2);
+    }
+}