1 files changed, 55 insertions, 0 deletions
diff --git a/tests/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs b/tests/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs
new file mode 100644
index 000000000..b3cce1b3a
--- /dev/null
+++ b/tests/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs
@@ -0,0 +1,55 @@
+// rust-lang/rust#55492: errors detected during MIR-borrowck's
+// analysis of a closure body may only be caught when AST-borrowck
+// looks at some parent.
+
+// transcribed from borrowck-closures-unique.rs
+mod borrowck_closures_unique {
+    pub fn e(x: &'static mut isize) {
+        static mut Y: isize = 3;
+        let mut c1 = |y: &'static mut isize| x = y;
+        //~^ ERROR is not declared as mutable
+        unsafe { c1(&mut Y); }
+    }
+}
+
+mod borrowck_closures_unique_grandparent {
+    pub fn ee(x: &'static mut isize) {
+        static mut Z: isize = 3;
+        let mut c1 = |z: &'static mut isize| {
+            let mut c2 = |y: &'static mut isize| x = y;
+        //~^ ERROR is not declared as mutable
+            c2(z);
+        };
+        unsafe { c1(&mut Z); }
+    }
+}
+
+// adapted from mutability_errors.rs
+mod mutability_errors {
+    pub fn capture_assign_whole(x: (i32,)) {
+        || { x = (1,); };
+        //~^ ERROR is not declared as mutable
+    }
+    pub fn capture_assign_part(x: (i32,)) {
+        || { x.0 = 1; };
+        //~^ ERROR is not declared as mutable
+    }
+    pub fn capture_reborrow_whole(x: (i32,)) {
+        || { &mut x; };
+        //~^ ERROR is not declared as mutable
+    }
+    pub fn capture_reborrow_part(x: (i32,)) {
+        || { &mut x.0; };
+        //~^ ERROR is not declared as mutable
+    }
+}
+
+fn main() {
+    static mut X: isize = 2;
+    unsafe { borrowck_closures_unique::e(&mut X); }
+
+    mutability_errors::capture_assign_whole((1000,));
+    mutability_errors::capture_assign_part((2000,));
+    mutability_errors::capture_reborrow_whole((3000,));
+    mutability_errors::capture_reborrow_part((4000,));
+}