From 9889e44470cbc6ae3c8e2fcfb6016ed15ed8cf51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=96mer=20Sinan=20A=C4=9Facan?= <omeragacan@gmail.com>
Date: Thu, 18 Feb 2021 17:53:09 +0300
Subject: [PATCH] Fix popping singleton paths in when generating E0433

Fixes #82156
---
 compiler/rustc_resolve/src/late.rs     | 11 +++++------
 src/test/ui/resolve/issue-82156.rs     |  3 +++
 src/test/ui/resolve/issue-82156.stderr |  9 +++++++++
 3 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 src/test/ui/resolve/issue-82156.rs
 create mode 100644 src/test/ui/resolve/issue-82156.stderr

diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index cca40a793dd00..bf7acddde7564 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -1801,7 +1801,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         crate_lint: CrateLint,
     ) -> PartialRes {
         tracing::debug!(
-            "smart_resolve_path_fragment(id={:?},qself={:?},path={:?}",
+            "smart_resolve_path_fragment(id={:?}, qself={:?}, path={:?})",
             id,
             qself,
             path
@@ -1841,11 +1841,10 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
             // Before we start looking for candidates, we have to get our hands
             // on the type user is trying to perform invocation on; basically:
-            // we're transforming `HashMap::new` into just `HashMap`
-            let path = if let Some((_, path)) = path.split_last() {
-                path
-            } else {
-                return Some(parent_err);
+            // we're transforming `HashMap::new` into just `HashMap`.
+            let path = match path.split_last() {
+                Some((_, path)) if !path.is_empty() => path,
+                _ => return Some(parent_err),
             };
 
             let (mut err, candidates) =
diff --git a/src/test/ui/resolve/issue-82156.rs b/src/test/ui/resolve/issue-82156.rs
new file mode 100644
index 0000000000000..6215259e48657
--- /dev/null
+++ b/src/test/ui/resolve/issue-82156.rs
@@ -0,0 +1,3 @@
+fn main() {
+    super(); //~ ERROR failed to resolve: there are too many leading `super` keywords
+}
diff --git a/src/test/ui/resolve/issue-82156.stderr b/src/test/ui/resolve/issue-82156.stderr
new file mode 100644
index 0000000000000..d53599dcce61b
--- /dev/null
+++ b/src/test/ui/resolve/issue-82156.stderr
@@ -0,0 +1,9 @@
+error[E0433]: failed to resolve: there are too many leading `super` keywords
+  --> $DIR/issue-82156.rs:2:5
+   |
+LL |     super();
+   |     ^^^^^ there are too many leading `super` keywords
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0433`.