From 64d98f8ee037282c35007b64c2649055c56af1db Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:19:03 +0200
Subject: Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 tests/ui/unsized/issue-40231-2.rs | 54 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 tests/ui/unsized/issue-40231-2.rs

(limited to 'tests/ui/unsized/issue-40231-2.rs')

diff --git a/tests/ui/unsized/issue-40231-2.rs b/tests/ui/unsized/issue-40231-2.rs
new file mode 100644
index 000000000..780433b28
--- /dev/null
+++ b/tests/ui/unsized/issue-40231-2.rs
@@ -0,0 +1,54 @@
+// check-pass
+
+#![allow(dead_code)]
+
+trait Structure<E>: Sized where E: Encoding {
+    type RefTarget: ?Sized;
+    type FfiPtr;
+    unsafe fn borrow_from_ffi_ptr<'a>(ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget>;
+}
+
+enum Slice {}
+
+impl<E> Structure<E> for Slice where E: Encoding {
+    type RefTarget = [E::Unit];
+    type FfiPtr = (*const E::FfiUnit, usize);
+    unsafe fn borrow_from_ffi_ptr<'a>(_ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget> {
+        panic!()
+    }
+}
+
+trait Encoding {
+    type Unit: Unit;
+    type FfiUnit;
+}
+
+trait Unit {}
+
+enum Utf16 {}
+
+impl Encoding for Utf16 {
+    type Unit = Utf16Unit;
+    type FfiUnit = u16;
+}
+
+struct Utf16Unit(pub u16);
+
+impl Unit for Utf16Unit {}
+
+struct SUtf16Str {
+    _data: <Slice as Structure<Utf16>>::RefTarget,
+}
+
+impl SUtf16Str {
+    pub unsafe fn from_ptr<'a>(ptr: <Slice as Structure<Utf16>>::FfiPtr)
+    -> Option<&'a Self> {
+        std::mem::transmute::<Option<&[<Utf16 as Encoding>::Unit]>, _>(
+            <Slice as Structure<Utf16>>::borrow_from_ffi_ptr(ptr))
+    }
+}
+
+fn main() {
+    const TEXT_U16: &'static [u16] = &[];
+    let _ = unsafe { SUtf16Str::from_ptr((TEXT_U16.as_ptr(), TEXT_U16.len())).unwrap() };
+}
-- 
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