Check array lengths to prevent OOB access

Author: phansch

clippy_lints/src/explicit_write.rs

@@ -52,9 +52,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
             if let ExprKind::MethodCall(ref write_fun, _, ref write_args) =
                 unwrap_args[0].node;
             // Obtain the string that should be printed
+            if write_args.len() > 1;
             if let ExprKind::Call(_, ref output_args) = write_args[1].node;
+            if output_args.len() > 0;
             if let ExprKind::AddrOf(_, ref output_string_expr) = output_args[0].node;
             if let ExprKind::Array(ref string_exprs) = output_string_expr.node;
+            if string_exprs.len() > 0;
             if let ExprKind::Lit(ref lit) = string_exprs[0].node;
             if let LitKind::Str(ref write_output, _) = lit.node;
             if write_fun.ident.name == "write_fmt";