Zlib::GzipReader#readline ArgumentError #8997
Description
Environment Information
$ jruby -v
jruby 9.4.14.0 (3.1.7) 2025-08-28 ddda6d5992 Java HotSpot(TM) 64-Bit Server VM 25.121-b13 on 1.8.0_121-b13 +jit [x86_64-darwin]
$ uname -a
Darwin MacBook-Air.local 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:40 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T8132 arm64
Expected Behavior
- CRuby/MRI
$ ruby -v
ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [arm64-darwin24]
$ irb -rzlib
irb(main):001> f = Zlib::GzipReader.open('./test/data/LostineRiver.kml.gz', encoding: 'utf-8')
=> #<Zlib::GzipReader:0x0000000124e181b8>
irb(main):002> f.readline('<')
=> "<"
https://docs.ruby-lang.org/en/3.4/Zlib/GzipReader.html#method-i-readline
readline (*args)
https://docs.ruby-lang.org/ja/latest/method/Zlib=3a=3aGzipReader/i/readline.html (Sorry. This is a Japanese document.)
readline(rs = $/) -> String
Actual Behavior
$ irb -rzlib
irb(main):001:0> f = Zlib::GzipReader.open('./test/data/LostineRiver.kml.gz', encoding: 'utf-8')
=> #<Zlib::GzipReader:0x3113a37>
irb(main):002:0> f.readline('<')
(irb):2:in `evaluate': `readline': wrong number of arguments (given 1, expected 0) (ArgumentError)
from org/jruby/RubyKernel.java:1277:in `eval'
from org/jruby/RubyKernel.java:1725:in `loop'
from org/jruby/RubyKernel.java:1426:in `catch'
from org/jruby/RubyKernel.java:1426:in `catch'
from /Users/naitoh/.rbenv/versions/jruby-9.4.14.0/lib/ruby/gems/shared/gems/irb-1.4.2/exe/irb:11:in `<main>'
from org/jruby/RubyKernel.java:1223:in `load'
from /Users/naitoh/.rbenv/versions/jruby-9.4.14.0/bin/irb:25:in `<main>'
I used the following gz file.
https://github.com/ruby/rexml/blob/master/test/data/LostineRiver.kml.gz