From e721f5e083d46853714e79c3c33eb492736cc189 Mon Sep 17 00:00:00 2001
From: QuietMisdreavus <grey@quietmisdreavus.net>
Date: Wed, 6 Mar 2019 10:16:41 -0600
Subject: [PATCH 1/2] don't process `external_traits` when collecting intra-doc
 links

---
 src/librustdoc/passes/collect_intra_doc_links.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 67f291285c447..93e811f8b31d8 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -213,6 +213,7 @@ impl<'a, 'tcx, 'rcx> LinkCollector<'a, 'tcx, 'rcx> {
                 _ => Err(())
             }
         } else {
+            debug!("attempting to resolve item without parent module: {}", path_str);
             Err(())
         }
     }
@@ -434,6 +435,15 @@ impl<'a, 'tcx, 'rcx> DocFolder for LinkCollector<'a, 'tcx, 'rcx> {
             self.fold_item_recur(item)
         }
     }
+
+    // FIXME: if we can resolve intra-doc links from other crates, we can use the stock
+    // `fold_crate`, but until then we should avoid scanning `krate.external_traits` since those
+    // will never resolve properly
+    fn fold_crate(&mut self, mut c: Crate) -> Crate {
+        c.module = c.module.take().and_then(|module| self.fold_item(module));
+
+        c
+    }
 }
 
 /// Resolves a string as a macro.

From 49cde404124c8217808c71972f206443f49bffc7 Mon Sep 17 00:00:00 2001
From: QuietMisdreavus <grey@quietmisdreavus.net>
Date: Wed, 6 Mar 2019 10:57:38 -0600
Subject: [PATCH 2/2] add test for spurious intra-doc link warning

---
 .../rustdoc/auxiliary/intra-links-external-traits.rs |  6 ++++++
 src/test/rustdoc/intra-links-external-traits.rs      | 12 ++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 src/test/rustdoc/auxiliary/intra-links-external-traits.rs
 create mode 100644 src/test/rustdoc/intra-links-external-traits.rs

diff --git a/src/test/rustdoc/auxiliary/intra-links-external-traits.rs b/src/test/rustdoc/auxiliary/intra-links-external-traits.rs
new file mode 100644
index 0000000000000..6142dcda986cf
--- /dev/null
+++ b/src/test/rustdoc/auxiliary/intra-links-external-traits.rs
@@ -0,0 +1,6 @@
+pub trait ThisTrait {
+    fn asdf(&self);
+
+    /// let's link to [`asdf`](ThisTrait::asdf)
+    fn qwop(&self);
+}
diff --git a/src/test/rustdoc/intra-links-external-traits.rs b/src/test/rustdoc/intra-links-external-traits.rs
new file mode 100644
index 0000000000000..d6b4a8ad58ad7
--- /dev/null
+++ b/src/test/rustdoc/intra-links-external-traits.rs
@@ -0,0 +1,12 @@
+// aux-build:intra-links-external-traits.rs
+// ignore-cross-compile
+
+#![crate_name = "outer"]
+#![deny(intra_doc_link_resolution_failure)]
+
+// using a trait that has intra-doc links on it from another crate (whether re-exporting or just
+// implementing it) used to give spurious resolution failure warnings
+
+extern crate intra_links_external_traits;
+
+pub use intra_links_external_traits::ThisTrait;