Auto merge of #9747 - kraktus:option_if_let_else, r=Manishearth

[`option_if_let_else`] do not lint if any arm has guard

fix https://github.com/rust-lang/rust-clippy/issues/9742

changelog: [`option_if_let_else`] do not lint if any arm has guard

clippy_lints/src/option_if_let_else.rs

@@ -213,11 +213,14 @@ fn try_convert_match<'tcx>(
     cx: &LateContext<'tcx>,
     arms: &[Arm<'tcx>],
 ) -> Option<(&'tcx Pat<'tcx>, &'tcx Expr<'tcx>, &'tcx Expr<'tcx>)> {
-    if arms.len() == 2 {
-        return if is_none_or_err_arm(cx, &arms[1]) {
-            Some((arms[0].pat, arms[0].body, arms[1].body))
-        } else if is_none_or_err_arm(cx, &arms[0]) {
-            Some((arms[1].pat, arms[1].body, arms[0].body))
+    if let [first_arm, second_arm] = arms
+        && first_arm.guard.is_none()
+        && second_arm.guard.is_none()
+        {
+        return if is_none_or_err_arm(cx, second_arm) {
+            Some((first_arm.pat, first_arm.body, second_arm.body))
+        } else if is_none_or_err_arm(cx, first_arm) {
+            Some((second_arm.pat, second_arm.body, first_arm.body))
         } else {
             None
         };

tests/ui/option_if_let_else.fixed

@@ -189,3 +189,12 @@ fn main() {
     let _ = res.map_or(1, |a| a + 1);
     let _ = res.map_or(5, |a| a + 1);
 }
+
+#[allow(dead_code)]
+fn issue9742() -> Option<&'static str> {
+    // should not lint because of guards
+    match Some("foo  ") {
+        Some(name) if name.starts_with("foo") => Some(name.trim()),
+        _ => None,
+    }
+}

tests/ui/option_if_let_else.rs

@@ -230,3 +230,12 @@ fn main() {
     };
     let _ = if let Ok(a) = res { a + 1 } else { 5 };
 }
+
+#[allow(dead_code)]
+fn issue9742() -> Option<&'static str> {
+    // should not lint because of guards
+    match Some("foo  ") {
+        Some(name) if name.starts_with("foo") => Some(name.trim()),
+        _ => None,
+    }
+}