From d2087ad00d5443f906a3603a1ba2718e87458239 Mon Sep 17 00:00:00 2001
From: Joe Ranweiler <joe@lemma.co>
Date: Tue, 22 Jun 2021 18:44:04 -0700
Subject: [PATCH 1/3] Remove bad cast in test, cover more cases

---
 tests/ui/zero_offset.rs     | 18 ++++++++----
 tests/ui/zero_offset.stderr | 55 +++++++++++++++++++++++++++++++++----
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/tests/ui/zero_offset.rs b/tests/ui/zero_offset.rs
index 2de904376ad4..d3f8c21937e9 100644
--- a/tests/ui/zero_offset.rs
+++ b/tests/ui/zero_offset.rs
@@ -1,12 +1,18 @@
 fn main() {
     unsafe {
-        let x = &() as *const ();
-        x.offset(0);
-        x.wrapping_add(0);
-        x.sub(0);
-        x.wrapping_sub(0);
+        let m = &mut () as *mut ();
+        m.offset(0);
+        m.wrapping_add(0);
+        m.sub(0);
+        m.wrapping_sub(0);
 
-        let y = &1 as *const u8;
+        let c = &() as *const ();
+        c.offset(0);
+        c.wrapping_add(0);
+        c.sub(0);
+        c.wrapping_sub(0);
+
+        let y = &1 as *const i32;
         y.offset(0);
     }
 }
diff --git a/tests/ui/zero_offset.stderr b/tests/ui/zero_offset.stderr
index cfcd7de2b3d2..b12c8e9a73c6 100644
--- a/tests/ui/zero_offset.stderr
+++ b/tests/ui/zero_offset.stderr
@@ -1,9 +1,52 @@
-error[E0606]: casting `&i32` as `*const u8` is invalid
-  --> $DIR/zero_offset.rs:9:17
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:4:9
    |
-LL |         let y = &1 as *const u8;
-   |                 ^^^^^^^^^^^^^^^
+LL |         m.offset(0);
+   |         ^^^^^^^^^^^
+   |
+   = note: `#[deny(clippy::zst_offset)]` on by default
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:5:9
+   |
+LL |         m.wrapping_add(0);
+   |         ^^^^^^^^^^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:6:9
+   |
+LL |         m.sub(0);
+   |         ^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:7:9
+   |
+LL |         m.wrapping_sub(0);
+   |         ^^^^^^^^^^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:10:9
+   |
+LL |         c.offset(0);
+   |         ^^^^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:11:9
+   |
+LL |         c.wrapping_add(0);
+   |         ^^^^^^^^^^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:12:9
+   |
+LL |         c.sub(0);
+   |         ^^^^^^^^
+
+error: offset calculation on zero-sized value
+  --> $DIR/zero_offset.rs:13:9
+   |
+LL |         c.wrapping_sub(0);
+   |         ^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 8 previous errors
 
-For more information about this error, try `rustc --explain E0606`.

From 10122e4a48c3a31276f8e117af66c949c8f962a3 Mon Sep 17 00:00:00 2001
From: Joe Ranweiler <joe@lemma.co>
Date: Tue, 22 Jun 2021 18:45:12 -0700
Subject: [PATCH 2/3] Remove shadowed receiver in check invocation

---
 clippy_lints/src/methods/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index c6bef7bc5d5e..21585543b0ac 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -2036,7 +2036,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
 fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Option<&RustcVersion>) {
     if let Some((name, [recv, args @ ..], span)) = method_call!(expr) {
         match (name, args) {
-            ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [recv, _]) => {
+            ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [_arg]) => {
                 zst_offset::check(cx, expr, recv);
             },
             ("and_then", [arg]) => {

From 642239c857124b109f43f7223baddbe8694c84ee Mon Sep 17 00:00:00 2001
From: Joe Ranweiler <joe@lemma.co>
Date: Tue, 22 Jun 2021 19:02:34 -0700
Subject: [PATCH 3/3] Update var name in test

---
 tests/ui/zero_offset.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/ui/zero_offset.rs b/tests/ui/zero_offset.rs
index d3f8c21937e9..6c190a4c86c4 100644
--- a/tests/ui/zero_offset.rs
+++ b/tests/ui/zero_offset.rs
@@ -12,7 +12,7 @@ fn main() {
         c.sub(0);
         c.wrapping_sub(0);
 
-        let y = &1 as *const i32;
-        y.offset(0);
+        let sized = &1 as *const i32;
+        sized.offset(0);
     }
 }