[Bug #684] io.read(nil, buf) で buf が変更されない


#1

Bug #684: io.read(nil, buf) e$B$Ge(B buf e$B$,JQ99$5$l$J$$e(B
http://redmine.ruby-lang.org/issues/show/684

e$B5/I<<Te(B: _ wanabe
e$B%9%F!<%?%9e(B: Open, e$BM%@hEYe(B: Normal

IO#read e$B$NBh0l0z?t$Ke(B
nile$B!"BhFs0z?t$K=PNO%P%C%U%!MQ$NJ8;zNs$r;XDj$7$?>l9ge(B
e$B=PNO%P%C%U%!$,JQ99$5$l$^$;$s!#e(B

$ ruby -ve
r, w = IO.pipe
w.print a
w.close
buf = x
p r.read(nil, buf)
p buf

ruby 1.9.0 (2008-10-26 revision 19941) [i386-mingw32]
a
x

e$B$3$N$h$&$J46$8$G$I$&$G$7$g$&$+!#e(B

Index: io.c

io.c (revision 19941)
+++ io.c (working copy)
@@ -1556,7 +1556,12 @@
int cr;

 if (NEED_READCONV(fptr)) {
  •    VALUE str = rb_str_new(NULL, 0);
    
  •    if (NIL_P(str)) {
    
  •        str = rb_str_new(NULL, 0);
    
  •    }
    
  •    else {
    
  •        rb_str_resize(str, 0);
    
  •    }
       make_readconv(fptr);
       while (1) {
           if (fptr->cbuf_len) {