Merge ref '6bcdcc73bd11' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: 6bcdcc73bd11568fd85f5a38b58e1eda054ad1cd
Filtered ref: 6cc4ce79e1f8dc0ec5a2e18049b9c1a51dee3221

This merge was created using https://github.com/rust-lang/josh-sync.

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/ui/drop/drop-count-assertion-16151.rs b/tests/ui/drop/drop-count-assertion-16151.rs
new file mode 100644
index 00000000000..ede6bc23e73
--- /dev/null
+++ b/tests/ui/drop/drop-count-assertion-16151.rs
@@ -0,0 +1,33 @@
+// https://github.com/rust-lang/rust/issues/16151
+//@ run-pass
+
+// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
+#![allow(static_mut_refs)]
+
+use std::mem;
+
+static mut DROP_COUNT: usize = 0;
+
+struct Fragment;
+
+impl Drop for Fragment {
+    fn drop(&mut self) {
+        unsafe {
+            DROP_COUNT += 1;
+        }
+    }
+}
+
+fn main() {
+    {
+        let mut fragments = vec![Fragment, Fragment, Fragment];
+        let _new_fragments: Vec<Fragment> = mem::replace(&mut fragments, vec![])
+            .into_iter()
+            .skip_while(|_fragment| {
+                true
+            }).collect();
+    }
+    unsafe {
+        assert_eq!(DROP_COUNT, 3);
+    }
+}