From 9decfff6f87d3e5760fd61375c3d27fa45a83e52 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 18 Nov 2022 17:23:10 +0000
Subject: [PATCH] Add fatal overflow test

---
 src/test/ui/typeck/hang-in-overflow.rs     | 19 +++++++++++++++++++
 src/test/ui/typeck/hang-in-overflow.stderr | 22 ++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/test/ui/typeck/hang-in-overflow.rs
 create mode 100644 src/test/ui/typeck/hang-in-overflow.stderr

diff --git a/src/test/ui/typeck/hang-in-overflow.rs b/src/test/ui/typeck/hang-in-overflow.rs
new file mode 100644
index 0000000000000..a8330c9b65c31
--- /dev/null
+++ b/src/test/ui/typeck/hang-in-overflow.rs
@@ -0,0 +1,19 @@
+// normalize-stderr-test "the requirement `.*`" -> "the requirement `...`"
+// normalize-stderr-test "required for `.*` to implement `.*`" -> "required for `...` to implement `...`"
+// normalize-stderr-test: ".*the full type name has been written to.*\n" -> ""
+
+// Currently this fatally aborts instead of hanging.
+// Make sure at least that this doesn't turn into a hang.
+
+fn f() {
+    foo::<_>();
+    //~^ ERROR overflow evaluating the requirement
+}
+
+fn foo<B>()
+where
+    Vec<[[[B; 1]; 1]; 1]>: PartialEq<B>,
+{
+}
+
+fn main() {}
diff --git a/src/test/ui/typeck/hang-in-overflow.stderr b/src/test/ui/typeck/hang-in-overflow.stderr
new file mode 100644
index 0000000000000..7a7b85b19b4ee
--- /dev/null
+++ b/src/test/ui/typeck/hang-in-overflow.stderr
@@ -0,0 +1,22 @@
+error[E0275]: overflow evaluating the requirement `...`
+  --> $DIR/hang-in-overflow.rs:9:5
+   |
+LL |     foo::<_>();
+   |     ^^^^^^^^
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`hang_in_overflow`)
+   = note: required for `...` to implement `...`
+   = note: 127 redundant requirements hidden
+   = note: required for `...` to implement `...`
+note: required by a bound in `foo`
+  --> $DIR/hang-in-overflow.rs:15:28
+   |
+LL | fn foo<B>()
+   |    --- required by a bound in this
+LL | where
+LL |     Vec<[[[B; 1]; 1]; 1]>: PartialEq<B>,
+   |                            ^^^^^^^^^^^^ required by this bound in `foo`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0275`.