Auto merge of rust-lang#12961 - GuillaumeGomez:fix-manual_unwrap_or_default, r=Alexendoo

Fix incorrect suggestion for `manual_unwrap_or_default`

Fixes rust-lang#12928.

If this not a "simple" pattern, better not emit the lint.

changelog: Fix incorrect suggestion for `manual_unwrap_or_default`

Author: bors

clippy_lints/src/manual_unwrap_or_default.rs

@@ -53,20 +53,15 @@ declare_lint_pass!(ManualUnwrapOrDefault => [MANUAL_UNWRAP_OR_DEFAULT]);
 
 fn get_some<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>) -> Option<HirId> {
     if let PatKind::TupleStruct(QPath::Resolved(_, path), &[pat], _) = pat.kind
+        && let PatKind::Binding(_, pat_id, _, _) = pat.kind
         && let Some(def_id) = path.res.opt_def_id()
         // Since it comes from a pattern binding, we need to get the parent to actually match
         // against it.
         && let Some(def_id) = cx.tcx.opt_parent(def_id)
         && (cx.tcx.lang_items().get(LangItem::OptionSome) == Some(def_id)
         || cx.tcx.lang_items().get(LangItem::ResultOk) == Some(def_id))
     {
-        let mut bindings = Vec::new();
-        pat.each_binding(|_, id, _, _| bindings.push(id));
-        if let &[id] = bindings.as_slice() {
-            Some(id)
-        } else {
-            None
-        }
+        Some(pat_id)
     } else {
         None
     }

tests/ui/manual_unwrap_or_default.fixed

@@ -78,3 +78,24 @@ fn issue_12569() {
         0
     };
 }
+
+// Should not warn!
+fn issue_12928() {
+    let x = Some((1, 2));
+    let y = if let Some((a, _)) = x { a } else { 0 };
+    let y = if let Some((a, ..)) = x { a } else { 0 };
+    let x = Some([1, 2]);
+    let y = if let Some([a, _]) = x { a } else { 0 };
+    let y = if let Some([a, ..]) = x { a } else { 0 };
+
+    struct X {
+        a: u8,
+        b: u8,
+    }
+    let x = Some(X { a: 0, b: 0 });
+    let y = if let Some(X { a, .. }) = x { a } else { 0 };
+    struct Y(u8, u8);
+    let x = Some(Y(0, 0));
+    let y = if let Some(Y(a, _)) = x { a } else { 0 };
+    let y = if let Some(Y(a, ..)) = x { a } else { 0 };
+}

tests/ui/manual_unwrap_or_default.rs

@@ -111,3 +111,24 @@ fn issue_12569() {
         0
     };
 }
+
+// Should not warn!
+fn issue_12928() {
+    let x = Some((1, 2));
+    let y = if let Some((a, _)) = x { a } else { 0 };
+    let y = if let Some((a, ..)) = x { a } else { 0 };
+    let x = Some([1, 2]);
+    let y = if let Some([a, _]) = x { a } else { 0 };
+    let y = if let Some([a, ..]) = x { a } else { 0 };
+
+    struct X {
+        a: u8,
+        b: u8,
+    }
+    let x = Some(X { a: 0, b: 0 });
+    let y = if let Some(X { a, .. }) = x { a } else { 0 };
+    struct Y(u8, u8);
+    let x = Some(Y(0, 0));
+    let y = if let Some(Y(a, _)) = x { a } else { 0 };
+    let y = if let Some(Y(a, ..)) = x { a } else { 0 };
+}