From c9be1a71b69fb99f9a10b1ba058138d374b5b3a9 Mon Sep 17 00:00:00 2001
From: yukang <moorekang@gmail.com>
Date: Sat, 5 Aug 2023 15:58:26 +0800
Subject: [PATCH] Remove invalid lint when there is a generic argument in
 prefix path

---
 compiler/rustc_resolve/src/late.rs                     |  3 ++-
 ...-114433-invalid-unused-qualifications-suggestion.rs | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 tests/ui/resolve/issue-114433-invalid-unused-qualifications-suggestion.rs

diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 7b590d16d8c..06da00f1135 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -3944,11 +3944,12 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
 
         if path.len() > 1
             && let Some(res) = result.full_res()
+            && let Some((&last_segment, prev_segs)) = path.split_last()
+            && prev_segs.iter().all(|seg| !seg.has_generic_args)
             && res != Res::Err
             && path[0].ident.name != kw::PathRoot
             && path[0].ident.name != kw::DollarCrate
         {
-            let last_segment = *path.last().unwrap();
             let unqualified_result = {
                 match self.resolve_path(&[last_segment], Some(ns), None) {
                     PathResult::NonModule(path_res) => path_res.expect_full_res(),
diff --git a/tests/ui/resolve/issue-114433-invalid-unused-qualifications-suggestion.rs b/tests/ui/resolve/issue-114433-invalid-unused-qualifications-suggestion.rs
new file mode 100644
index 00000000000..83349dd3350
--- /dev/null
+++ b/tests/ui/resolve/issue-114433-invalid-unused-qualifications-suggestion.rs
@@ -0,0 +1,10 @@
+#![deny(unused_qualifications)]
+// check-pass
+fn bar() {
+    match Option::<Option<()>>::None {
+        Some(v) => {}
+        None => {}
+    }
+}
+
+fn main() {}