Re: [PATCH] left shift of negative value do_binop src/arith_yacc.c:111:12

Harald van Dijk wrote in
 <[email protected]>:
 |On 31/07/2025 19:49, Aleksander Ushakov wrote:
 |> There is a fix of the problem:
 |> 
 |> diff --git a/src/arith_yacc.c b/src/arith_yacc.c
 |> index 1a087c3..e23060d 100644
 |> --- a/src/arith_yacc.c
 |> +++ b/src/arith_yacc.c
 |> @@ -108,7 +108,9 @@ static intmax_t do_binop(int op, intmax_t a, 
 |> intmax_t b)
 |>          case ARITH_SUB:
 |>                  return a - b;
 |>          case ARITH_LSHIFT:
 |> -               return a << b;
 |> +               if (a < 0)
 |> +                       yyerror("left shift of negative value");
 |> +               return (intmax_t)a << b;
 |>          case ARITH_RSHIFT:
 |>                  return a >> b;
 |>          case ARITH_LT:
 |If other major shells already issued an error here, this change would 
 |look fine (except again incomplete -- there is a lot more potential to 
 |trigger sanitizer messages in this file), but as other major shells 
 |accept this, I think dash should continue to accept this too.

Well said.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)
|
|During summer's humble, here's David Leonard's grumble
|
|The black bear,          The black bear,
|blithely holds his own   holds himself at leisure
|beating it, up and down  tossing over his ups and downs with pleasure
|
|Farewell, dear collar bear