From 775f1e5acdeae38eae7de41b22bdf6ab71e34efd Mon Sep 17 00:00:00 2001
From: thiolliere <gui.thiolliere@gmail.com>
Date: Thu, 12 Nov 2020 12:41:19 +0100
Subject: [PATCH] fix pretty print for qpath

---
 compiler/rustc_ast_pretty/src/pprust/state.rs  | 11 ++++++-----
 src/test/pretty/qpath-associated-type-bound.rs | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 5 deletions(-)
 create mode 100644 src/test/pretty/qpath-associated-type-bound.rs

diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
index a64014f5acb..62a9452c9f0 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -2328,11 +2328,12 @@ fn print_qpath(&mut self, path: &ast::Path, qself: &ast::QSelf, colons_before_pa
             self.print_path(path, false, depth);
         }
         self.s.word(">");
-        self.s.word("::");
-        let item_segment = path.segments.last().unwrap();
-        self.print_ident(item_segment.ident);
-        if let Some(ref args) = item_segment.args {
-            self.print_generic_args(args, colons_before_params)
+        for item_segment in &path.segments[qself.position..] {
+            self.s.word("::");
+            self.print_ident(item_segment.ident);
+            if let Some(ref args) = item_segment.args {
+                self.print_generic_args(args, colons_before_params)
+            }
         }
     }
 
diff --git a/src/test/pretty/qpath-associated-type-bound.rs b/src/test/pretty/qpath-associated-type-bound.rs
new file mode 100644
index 00000000000..e06885e0388
--- /dev/null
+++ b/src/test/pretty/qpath-associated-type-bound.rs
@@ -0,0 +1,16 @@
+// pp-exact
+
+
+mod m {
+    pub trait Tr {
+        type Ts: super::Tu;
+    }
+}
+
+trait Tu {
+    fn dummy() { }
+}
+
+fn foo<T: m::Tr>() { <T as m::Tr>::Ts::dummy(); }
+
+fn main() { }