Add test for #45868

Author: Manishearth

src/test/run-make/rustdoc-error-lines/Makefile

@@ -0,0 +1,8 @@
+-include ../tools.mk
+
+# Test that hir-tree output doens't crash and includes
+# the string constant we would expect to see.
+
+all:
+	$(RUSTDOC) --test input.rs > $(TMPDIR)/output || true
+	$(CGREP) 'input.rs:17:15' < $(TMPDIR)/output

src/test/run-make/rustdoc-error-lines/input.rs

@@ -0,0 +1,21 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test for #45868
+
+// random #![feature] to ensure that crate attrs
+// do not offset things
+/// ```rust
+/// #![feature(nll)]
+/// let x: char = 1;
+/// ```
+pub fn foo() {
+
+}