From: shyouhei@... Date: 2018-12-26T01:44:53+00:00 Subject: [ruby-core:90723] [Ruby trunk Bug#15460] Behaviour of String#setbyte changed Issue #15460 has been updated by shyouhei (Shyouhei Urabe). We may want to define the behaviour of these methods without introducing fixnum / bignum distinction. One possible way is: ```patch Index: io.c =================================================================== --- io.c (revision 66566) +++ io.c (working copy) @@ -4259,8 +4259,8 @@ rb_io_ungetbyte(VALUE io, VALUE b) GetOpenFile(io, fptr); rb_io_check_byte_readable(fptr); if (NIL_P(b)) return Qnil; - if (FIXNUM_P(b)) { - int i = FIX2INT(b); + if (RB_TYPE_P(b, T_FIXNUM) || RB_TYPE_P(b, T_BIGNUM)) { + int i = NUM2INT(rb_int_modulo(b, INT2FIX(256))); if (0 <= i && i <= UCHAR_MAX) { unsigned char cc = i & 0xFF; b = rb_str_new((const char *)&cc, 1); Index: string.c =================================================================== --- string.c (revision 66566) +++ string.c (working copy) @@ -5411,7 +5411,7 @@ static VALUE rb_str_setbyte(VALUE str, VALUE index, VALUE value) { long pos = NUM2LONG(index); - int byte = NUM2INT(value); + int byte = NUM2INT(rb_int_modulo(value, INT2FIX(256))); long len = RSTRING_LEN(str); char *head, *left = 0; unsigned char *ptr; ``` ---------------------------------------- Bug #15460: Behaviour of String#setbyte changed https://bugs.ruby-lang.org/issues/15460#change-75900 * Author: gettalong (Thomas Leitner) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-linux] * Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN ---------------------------------------- I just installed Ruby 2.6.0 for benchmarking reasons and found that the change [string.c: setbyte silently ignores upper bits](https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/65804) broke my library/application HexaPDF. Before using String#setbyte I tested how it would respond to values lower than 0 or greater than 255 and found that it automatically performed the needed modulo 256 operation (at least up to Ruby 2.5.3). Therefore I left out the explicit modulo operation for performance reasons. Would it make sense to change the String#setbyte implementation to perform the modulo operation? This would restore compatibility with prior Ruby versions and may be what people would expect. -- https://bugs.ruby-lang.org/ Unsubscribe: