Merge commit '6ed6f1e6a1' into clippyup

clippy_lints/src/methods/iterator_step_by_zero.rs

@@ -0,0 +1,19 @@
+use crate::consts::{constant, Constant};
+use crate::utils::{match_trait_method, paths, span_lint};
+use rustc_hir as hir;
+use rustc_lint::LateContext;
+
+use super::ITERATOR_STEP_BY_ZERO;
+
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, args: &'tcx [hir::Expr<'_>]) {
+    if match_trait_method(cx, expr, &paths::ITERATOR) {
+        if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &args[1]) {
+            span_lint(
+                cx,
+                ITERATOR_STEP_BY_ZERO,
+                expr.span,
+                "`Iterator::step_by(0)` will panic at runtime",
+            );
+        }
+    }
+}