diff --git a/clippy_lints/src/methods/filter_map_identity.rs b/clippy_lints/src/methods/filter_map_identity.rs index cf7f276dabb1..b04d761d4860 100644 --- a/clippy_lints/src/methods/filter_map_identity.rs +++ b/clippy_lints/src/methods/filter_map_identity.rs @@ -2,6 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::{is_expr_identity_function, is_expr_untyped_identity_function, is_trait_method}; use rustc_errors::Applicability; use rustc_hir as hir; +use rustc_hir::ExprKind; use rustc_lint::LateContext; use rustc_span::{Span, sym}; @@ -21,6 +22,15 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, filter_map_arg: if is_trait_method(cx, expr, sym::Iterator) && let Some(applicability) = is_identity(cx, filter_map_arg) { + // check if the iterator is from an empty array, see issue #12653 + if let ExprKind::MethodCall(_, recv, ..) = expr.kind + && let ExprKind::MethodCall(_, recv2, ..) = recv.kind + && let ExprKind::Array(arr) = recv2.kind + && arr.is_empty() + { + return; + } + span_lint_and_sugg( cx, FILTER_MAP_IDENTITY, diff --git a/tests/ui/filter_map_identity.fixed b/tests/ui/filter_map_identity.fixed index f3f6848e5f92..fdd020fcd773 100644 --- a/tests/ui/filter_map_identity.fixed +++ b/tests/ui/filter_map_identity.fixed @@ -81,3 +81,8 @@ fn main() { //~^ ERROR: use of } } + +fn issue12653() -> impl Iterator { + [].into_iter().filter_map(|x| x) + // No lint +} diff --git a/tests/ui/filter_map_identity.rs b/tests/ui/filter_map_identity.rs index b9aa9c05be89..a626de9f5bbd 100644 --- a/tests/ui/filter_map_identity.rs +++ b/tests/ui/filter_map_identity.rs @@ -81,3 +81,8 @@ fn main() { //~^ ERROR: use of } } + +fn issue12653() -> impl Iterator { + [].into_iter().filter_map(|x| x) + // No lint +}