Bug #20787
Updated by nobu (Nobuyoshi Nakada) about 2 months ago
In revision commit:d3574c117a637a4456aa3ee78e24d8df510b9355, d3574c117a637a4456aa3ee78e24d8df510b9355, the implementation of IO#readline was modified and consequently broke argument handling in a subtle way. It no longer checks that the encoding of the separator string is compatible with the internal encoding of the stream. Prior to version 3.3.0, the following script raises an ArgumentError when calling #readline: ```ruby require "tempfile" Tempfile.open(encoding: "utf-8:utf-32le") { |f| f.write("0123456789"); f.rewind; f.readline("\0", 1); } ``` After 3.3.0, the script will read all the data in the file, in this case 40 bytes, even though the limit argument is 1. Replacing #readline with #gets raises the ArgumentError in all versions. I'm fairly sure that the failure to check the separator string encoding leads to the incorrect handling of the limit argument.