Bug #11841: StringIO with read and `nil, ''` arguments broken with enabled frozen string literal

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: ruby 2.3.0dev (2015-12-19 trunk 53195) [x86_64-darwin15]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

[deepj (deepj #)]

I'm not sure what behavior is expected here. But the following use case is used in rack (https://github.com/rack/rack/blob/master/test/spec_lint.rb#L496). If frozen string literal is enabled it throws `read': can't modify frozen String (RuntimeError), otherwise nothing.

# frozen_string_literal: true

io = StringIO.new('')

io.read(*[nil, ''])

[deepj (deepj #)]

• ruby -v set to ruby 2.3.0dev (2015-12-19 trunk 53195) [x86_64-darwin15]

[shugo (Shugo Maeda)]

• Status changed from Open to Rejected

deepj # wrote:

# frozen_string_literal: true

io = StringIO.new('')

io.read(*[nil, ''])

The second argument of StringIO#read is a buffer to read, so it shouldn't be frozen.

io.read(*[nil, String.new])

[deepj (deepj #)]

Thanks. In fact, I didn't realized the second argument is actually a buffer. My mistake