Let String#slice! return nil (#3533)

Returns `nil` instead of an empty string when non-integer number is given (to make it 2.7 compatible).

1 files changed, 4 insertions, 1 deletions

diff --git a/string.c b/string.c
index 7cfeaae180..0c4e76a1a7 100644
--- a/string.c
+++ b/string.c
@@ -4961,7 +4961,10 @@ rb_str_slice_bang(int argc, VALUE *argv, VALUE str)
 	    return Qnil;
 	  case Qfalse:
 	    beg = NUM2LONG(indx);
-	    goto num_index;
+	    if (!(p = rb_str_subpos(str, beg, &len))) return Qnil;
+	    if (!len) return Qnil;
+	    beg = p - RSTRING_PTR(str);
+	    goto subseq;
 	  default:
 	    goto num_index;
 	}