From 0943a6b188e11339d217d43f39322f51d2d8187d Mon Sep 17 00:00:00 2001
From: trevyn <230691+trevyn@users.noreply.github.com>
Date: Sat, 20 Jan 2024 01:22:52 +0400
Subject: [PATCH 1/2] add test issue-117965

---
 tests/ui/single-use-lifetime/issue-117965.rs  | 18 ++++++++++++++++
 .../single-use-lifetime/issue-117965.stderr   | 21 +++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 tests/ui/single-use-lifetime/issue-117965.rs
 create mode 100644 tests/ui/single-use-lifetime/issue-117965.stderr

diff --git a/tests/ui/single-use-lifetime/issue-117965.rs b/tests/ui/single-use-lifetime/issue-117965.rs
new file mode 100644
index 00000000000..5eb2a03e13d
--- /dev/null
+++ b/tests/ui/single-use-lifetime/issue-117965.rs
@@ -0,0 +1,18 @@
+#![deny(single_use_lifetimes)]
+
+pub enum Data<'a> {
+    Borrowed(&'a str),
+    Owned(String),
+}
+
+impl<'a> Data<'a> {
+    pub fn get<'b: 'a>(&'b self) -> &'a str {
+        //~^ ERROR lifetime parameter `'b` only used once
+        match &self {
+            Self::Borrowed(val) => val,
+            Self::Owned(val) => &val,
+        }
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/single-use-lifetime/issue-117965.stderr b/tests/ui/single-use-lifetime/issue-117965.stderr
new file mode 100644
index 00000000000..e789e183546
--- /dev/null
+++ b/tests/ui/single-use-lifetime/issue-117965.stderr
@@ -0,0 +1,21 @@
+error: lifetime parameter `'b` only used once
+  --> $DIR/issue-117965.rs:9:16
+   |
+LL |     pub fn get<'b: 'a>(&'b self) -> &'a str {
+   |                ^^       -- ...is used only here
+   |                |
+   |                this lifetime...
+   |
+note: the lint level is defined here
+  --> $DIR/issue-117965.rs:1:9
+   |
+LL | #![deny(single_use_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+help: elide the single-use lifetime
+   |
+LL -     pub fn get<'b: 'a>(&'b self) -> &'a str {
+LL +     pub fn get(&self) -> &'a str {
+   |
+
+error: aborting due to 1 previous error
+

From de2575f35d46dfa2b24eb205ef133a679bff1b31 Mon Sep 17 00:00:00 2001
From: trevyn <230691+trevyn@users.noreply.github.com>
Date: Sat, 20 Jan 2024 02:30:58 +0400
Subject: [PATCH 2/2] Don't delete any lifetimes with bounds

---
 compiler/rustc_resolve/src/late/diagnostics.rs   | 3 ++-
 tests/ui/single-use-lifetime/issue-117965.stderr | 5 -----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 5a95f2083f6..abb0a7a465a 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -2567,8 +2567,9 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                     debug!(?param.ident, ?param.ident.span, ?use_span);
 
                     let elidable = matches!(use_ctxt, LifetimeCtxt::Ref);
+                    let deletion_span =
+                        if param.bounds.is_empty() { deletion_span() } else { None };
 
-                    let deletion_span = deletion_span();
                     self.r.lint_buffer.buffer_lint_with_diagnostic(
                         lint::builtin::SINGLE_USE_LIFETIMES,
                         param.id,
diff --git a/tests/ui/single-use-lifetime/issue-117965.stderr b/tests/ui/single-use-lifetime/issue-117965.stderr
index e789e183546..ed14ab92f4d 100644
--- a/tests/ui/single-use-lifetime/issue-117965.stderr
+++ b/tests/ui/single-use-lifetime/issue-117965.stderr
@@ -11,11 +11,6 @@ note: the lint level is defined here
    |
 LL | #![deny(single_use_lifetimes)]
    |         ^^^^^^^^^^^^^^^^^^^^
-help: elide the single-use lifetime
-   |
-LL -     pub fn get<'b: 'a>(&'b self) -> &'a str {
-LL +     pub fn get(&self) -> &'a str {
-   |
 
 error: aborting due to 1 previous error