2 files changed, 135 insertions, 0 deletions
diff --git a/tests/ui/entry_unfixable.rs b/tests/ui/entry_unfixable.rs
new file mode 100644
index 00000000000..dbdacf95056
--- /dev/null
+++ b/tests/ui/entry_unfixable.rs
@@ -0,0 +1,94 @@
+#![allow(unused, clippy::needless_pass_by_value, clippy::collapsible_if)]
+#![warn(clippy::map_entry)]
+//@no-rustfix
+
+use std::collections::HashMap;
+use std::hash::Hash;
+
+macro_rules! m {
+    ($e:expr) => {{ $e }};
+}
+
+macro_rules! insert {
+    ($map:expr, $key:expr, $val:expr) => {
+        $map.insert($key, $val)
+    };
+}
+
+mod issue13306 {
+    use std::collections::HashMap;
+
+    struct Env {
+        enclosing: Option<Box<Env>>,
+        values: HashMap<String, usize>,
+    }
+
+    impl Env {
+        fn assign(&mut self, name: String, value: usize) -> bool {
+            if !self.values.contains_key(&name) {
+                //~^ map_entry
+                self.values.insert(name, value);
+                true
+            } else if let Some(enclosing) = &mut self.enclosing {
+                enclosing.assign(name, value)
+            } else {
+                false
+            }
+        }
+    }
+}
+
+fn issue9925(mut hm: HashMap<String, bool>) {
+    let key = "hello".to_string();
+    if hm.contains_key(&key) {
+        //~^ map_entry
+        let bval = hm.get_mut(&key).unwrap();
+        *bval = false;
+    } else {
+        hm.insert(key, true);
+    }
+}
+
+mod issue9470 {
+    use std::collections::HashMap;
+    use std::sync::Mutex;
+
+    struct Interner(i32);
+
+    impl Interner {
+        const fn new() -> Self {
+            Interner(0)
+        }
+
+        fn resolve(&self, name: String) -> Option<String> {
+            todo!()
+        }
+    }
+
+    static INTERNER: Mutex<Interner> = Mutex::new(Interner::new());
+
+    struct VM {
+        stack: Vec<i32>,
+        globals: HashMap<String, i32>,
+    }
+
+    impl VM {
+        fn stack_top(&self) -> &i32 {
+            self.stack.last().unwrap()
+        }
+
+        fn resolve(&mut self, name: String, value: i32) -> Result<(), String> {
+            if self.globals.contains_key(&name) {
+                //~^ map_entry
+                self.globals.insert(name, value);
+            } else {
+                let interner = INTERNER.lock().unwrap();
+                return Err(interner.resolve(name).unwrap().to_owned());
+            }
+
+            Ok(())
+        }
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/entry_unfixable.stderr b/tests/ui/entry_unfixable.stderr
new file mode 100644
index 00000000000..9f9956d351b
--- /dev/null
+++ b/tests/ui/entry_unfixable.stderr
@@ -0,0 +1,41 @@
+error: usage of `contains_key` followed by `insert` on a `HashMap`
+  --> tests/ui/entry_unfixable.rs:28:13
+   |
+LL | /             if !self.values.contains_key(&name) {
+LL | |
+LL | |                 self.values.insert(name, value);
+LL | |                 true
+...  |
+LL | |                 false
+LL | |             }
+   | |_____________^
+   |
+   = note: `-D clippy::map-entry` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::map_entry)]`
+
+error: usage of `contains_key` followed by `insert` on a `HashMap`
+  --> tests/ui/entry_unfixable.rs:43:5
+   |
+LL | /     if hm.contains_key(&key) {
+LL | |
+LL | |         let bval = hm.get_mut(&key).unwrap();
+LL | |         *bval = false;
+LL | |     } else {
+LL | |         hm.insert(key, true);
+LL | |     }
+   | |_____^
+
+error: usage of `contains_key` followed by `insert` on a `HashMap`
+  --> tests/ui/entry_unfixable.rs:81:13
+   |
+LL | /             if self.globals.contains_key(&name) {
+LL | |
+LL | |                 self.globals.insert(name, value);
+LL | |             } else {
+LL | |                 let interner = INTERNER.lock().unwrap();
+LL | |                 return Err(interner.resolve(name).unwrap().to_owned());
+LL | |             }
+   | |_____________^
+
+error: aborting due to 3 previous errors
+