From 4becbf3a7936d25de06265d934378996eea2f857 Mon Sep 17 00:00:00 2001
From: "Felix S. Klock II" <pnkfelix@pnkfx.org>
Date: Tue, 9 Jul 2019 11:56:01 +0200
Subject: [PATCH] Regression test for issue 42574.

---
 ...ssue-42574-diagnostic-in-nested-closure.rs | 13 ++++++++++
 ...-42574-diagnostic-in-nested-closure.stderr | 26 +++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.rs
 create mode 100644 src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.stderr

diff --git a/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.rs b/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.rs
new file mode 100644
index 0000000000000..f45370e5c2e5b
--- /dev/null
+++ b/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.rs
@@ -0,0 +1,13 @@
+// This test illustrates a case where full NLL (enabled by the feature
+// switch below) produces superior diagnostics to the NLL-migrate
+// mode.
+
+#![feature(nll)]
+
+fn doit(data: &'static mut ()) {
+    || doit(data);
+    //~^ ERROR lifetime may not live long enough
+    //~| ERROR `data` does not live long enough
+}
+
+fn main() { }
diff --git a/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.stderr b/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.stderr
new file mode 100644
index 0000000000000..4c70a8475f24f
--- /dev/null
+++ b/src/test/ui/nll/issue-42574-diagnostic-in-nested-closure.stderr
@@ -0,0 +1,26 @@
+error: lifetime may not live long enough
+  --> $DIR/issue-42574-diagnostic-in-nested-closure.rs:8:8
+   |
+LL |     || doit(data);
+   |     -- ^^^^^^^^^^ argument requires that `'1` must outlive `'static`
+   |     |
+   |     lifetime `'1` represents this closure's body
+   |
+   = note: closure implements `FnMut`, so references to captured variables can't escape the closure
+
+error[E0597]: `data` does not live long enough
+  --> $DIR/issue-42574-diagnostic-in-nested-closure.rs:8:13
+   |
+LL |     || doit(data);
+   |     -- -----^^^^-
+   |     |  |    |
+   |     |  |    borrowed value does not live long enough
+   |     |  argument requires that `data` is borrowed for `'static`
+   |     value captured here
+...
+LL | }
+   |  - `data` dropped here while still borrowed
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0597`.