* io.c (io_read): [ruby-dev:24952]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@7359 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Wed Nov 24 01:01:31 2004  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* io.c (io_read): [ruby-dev:24952]
+
 Tue Nov 23 08:09:50 2004  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
 
 	* ext/tk/lib/tk/menu.rb: improve usability of TkOptionMenubutton

io.c

@@ -1197,17 +1197,19 @@ io_read(argc, argv, io)
 
     rb_scan_args(argc, argv, "02", &length, &str);
 
+    if (!NIL_P(length)) {
+	len = NUM2LONG(length);
+	if (len < 0) {
+	    rb_raise(rb_eArgError, "negative length %ld given", len);
+	}
+    }
+
     GetOpenFile(io, fptr);
     rb_io_check_readable(fptr);
+
     if (NIL_P(length)) {
 	return read_all(fptr, remain_size(fptr), str);
     }
-
-    len = NUM2LONG(length);
-    if (len < 0) {
-	rb_raise(rb_eArgError, "negative length %ld given", len);
-    }
-
     if (feof(fptr->f)) return Qnil;
     if (NIL_P(str)) {
 	str = rb_str_new(0, len);