Bug #11417: Wrong description for `limit` parameter for IO#gets

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

[asterite (Ary Borenszweig)]

It says:

"If the first argument is an integer, or optional second argument is given, the returning string would not be longer than the given value in bytes."

But:

require "stringio"

io = StringIO.new "こんにちは"
string = io.gets(1)
puts string #=> "こ"
puts string.bytes.length #=> 3

The returning value number of bytes (3) is longer than the given value (1), so it contradicts the description.

I guess the implementation reads chars until the total number of bytes read is equal or bigger than the limit.

But I don't know how to describe this behaviour in a way that's clear to the user.

[davydov_anton (Anton Davydov)]

Ary hello!

The problem in UTF-8 encoding. For example japanese characters are represented by 3 bytes:

StringIO.new("こんにちは").gets(1) # => "こ"
StringIO.new("こんにちは").gets(2) # => "こ"
StringIO.new("こんにちは").gets(3) # => "こ"
StringIO.new("こんにちは").gets(4) # => "こん"

Also I created RP in ruby/ruby repository where I updated IO#gets documentation.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed

This was fixed in 965e9df38045594d126991e6a109c5746242d2ba.