1 files changed, 88 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-20427.rs b/src/test/ui/issues/issue-20427.rs
new file mode 100644
index 000000000..cfd8b2191
--- /dev/null
+++ b/src/test/ui/issues/issue-20427.rs
@@ -0,0 +1,88 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_imports)]
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(deprecated, deprecated_in_future)]
+
+// aux-build:i8.rs
+
+extern crate i8;
+use std::string as i16;
+static i32: i32 = 0;
+const i64: i64 = 0;
+fn u8(f32: f32) {}
+fn f<f64>(f64: f64) {}
+enum u32 {}
+struct u64;
+trait bool {}
+
+mod char {
+    extern crate i8;
+    static i32_: i32 = 0;
+    const i64_: i64 = 0;
+    fn u8_(f32: f32) {}
+    fn f_<f64_>(f64: f64_) {}
+    type u16_ = u16;
+    enum u32_ {}
+    struct u64_;
+    trait bool_ {}
+    mod char_ {}
+
+    mod str {
+        use super::i8 as i8;
+        use super::i32_ as i32;
+        use super::i64_ as i64;
+        use super::u8_ as u8;
+        use super::f_ as f64;
+        use super::u16_ as u16;
+        use super::u32_ as u32;
+        use super::u64_ as u64;
+        use super::bool_ as bool;
+        use super::{bool_ as str};
+        use super::char_ as char;
+    }
+}
+
+trait isize_ {
+    type isize;
+}
+
+fn usize<'usize>(usize: &'usize usize) -> &'usize usize { usize }
+
+mod reuse {
+    use std::mem::size_of;
+
+    type u8 = u64;
+    use std::string::String as i16;
+
+    pub fn check<u16>() {
+        assert_eq!(size_of::<u8>(), 8);
+        assert_eq!(size_of::<::u64>(), 0);
+        assert_eq!(size_of::<i16>(), 3 * size_of::<*const ()>());
+        assert_eq!(size_of::<u16>(), 0);
+    }
+}
+
+mod guard {
+    pub fn check() {
+        use std::u8; // bring module u8 in scope
+        fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
+            u8::max_value() // OK, resolves to associated function <u8>::max_value,
+                            // not to non-existent std::u8::max_value
+        }
+        assert_eq!(f(), u8::MAX); // OK, resolves to std::u8::MAX
+    }
+}
+
+fn main() {
+    let bool = true;
+    let _ = match bool {
+        str @ true => if str { i32 as i64 } else { i64 },
+        false => i64,
+    };
+
+    reuse::check::<u64>();
+    guard::check();
+}