[`map_entry`]: Check insert expression for map use

The lint makes sure that the map is not used (borrowed) before the call
to `insert`. Since the lint creates a mutable borrow on the map with the
`Entry`, it wouldn't be possible to replace such code with `Entry`.
However, expressions up to the `insert` call are checked, but not
expressions for the arguments of the `insert` call itself. This commit
fixes that.

Fixes #11935

2 files changed, 22 insertions, 0 deletions

diff --git a/tests/ui/entry.fixed b/tests/ui/entry.fixed
index 4099fe7e139..71ec13f4610 100644
--- a/tests/ui/entry.fixed
+++ b/tests/ui/entry.fixed
@@ -165,4 +165,15 @@ pub fn issue_10331() {
     }
 }
 
+/// Issue 11935
+/// Do not suggest using entries if the map is used inside the `insert` expression.
+pub fn issue_11935() {
+    let mut counts: HashMap<u64, u64> = HashMap::new();
+    if !counts.contains_key(&1) {
+        counts.insert(1, 1);
+    } else {
+        counts.insert(1, counts.get(&1).unwrap() + 1);
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/entry.rs b/tests/ui/entry.rs
index 409be0aa060..86092b7c055 100644
--- a/tests/ui/entry.rs
+++ b/tests/ui/entry.rs
@@ -169,4 +169,15 @@ pub fn issue_10331() {
     }
 }
 
+/// Issue 11935
+/// Do not suggest using entries if the map is used inside the `insert` expression.
+pub fn issue_11935() {
+    let mut counts: HashMap<u64, u64> = HashMap::new();
+    if !counts.contains_key(&1) {
+        counts.insert(1, 1);
+    } else {
+        counts.insert(1, counts.get(&1).unwrap() + 1);
+    }
+}
+
 fn main() {}