From fd4c6e903b0161cedb2297e2de25783842dffe2b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 11 Apr 2019 16:15:48 -0700
Subject: [PATCH 1/2] Remove duplicated redundant spans

---
 src/librustc_resolve/resolve_imports.rs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 97b630ba5f298..2c98c66c62e37 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1310,15 +1310,14 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
         if !is_redundant.is_empty() &&
             is_redundant.present_items().all(|is_redundant| is_redundant)
         {
+            let mut redundant_spans: Vec<_> = redundant_span.present_items().collect();
+            redundant_spans.dedup();
             self.session.buffer_lint_with_diagnostic(
                 UNUSED_IMPORTS,
                 directive.id,
                 directive.span,
                 &format!("the item `{}` is imported redundantly", ident),
-                BuiltinLintDiagnostics::RedundantImport(
-                    redundant_span.present_items().collect(),
-                    ident,
-                ),
+                BuiltinLintDiagnostics::RedundantImport(redundant_spans, ident),
             );
         }
     }

From ca5a9ce2a131b117f1d7f70163d96623ab9ca213 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Fri, 12 Apr 2019 11:42:52 -0700
Subject: [PATCH 2/2] Add test and fix dedup

---
 src/librustc_resolve/resolve_imports.rs |  1 +
 src/test/ui/issues/issue-59896.rs       | 10 ++++++++++
 src/test/ui/issues/issue-59896.stderr   | 17 +++++++++++++++++
 3 files changed, 28 insertions(+)
 create mode 100644 src/test/ui/issues/issue-59896.rs
 create mode 100644 src/test/ui/issues/issue-59896.stderr

diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 2c98c66c62e37..e3909b466558d 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1311,6 +1311,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             is_redundant.present_items().all(|is_redundant| is_redundant)
         {
             let mut redundant_spans: Vec<_> = redundant_span.present_items().collect();
+            redundant_spans.sort();
             redundant_spans.dedup();
             self.session.buffer_lint_with_diagnostic(
                 UNUSED_IMPORTS,
diff --git a/src/test/ui/issues/issue-59896.rs b/src/test/ui/issues/issue-59896.rs
new file mode 100644
index 0000000000000..cecf2c5c22b81
--- /dev/null
+++ b/src/test/ui/issues/issue-59896.rs
@@ -0,0 +1,10 @@
+#![deny(unused_imports)]
+
+struct S;
+
+fn main() {
+    use S;  //~ ERROR the item `S` is imported redundantly
+
+    let _s = S;
+}
+
diff --git a/src/test/ui/issues/issue-59896.stderr b/src/test/ui/issues/issue-59896.stderr
new file mode 100644
index 0000000000000..ef78f27fa69a3
--- /dev/null
+++ b/src/test/ui/issues/issue-59896.stderr
@@ -0,0 +1,17 @@
+error: the item `S` is imported redundantly
+  --> $DIR/issue-59896.rs:6:9
+   |
+LL | struct S;
+   | --------- the item `S` is already defined here
+...
+LL |     use S;
+   |         ^
+   |
+note: lint level defined here
+  --> $DIR/issue-59896.rs:1:9
+   |
+LL | #![deny(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+