From: "nobu (Nobuyoshi Nakada)" <nobu@...>
Date: 2013-04-29T09:35:57+09:00
Subject: [ruby-core:54678] [ruby-trunk - Bug #8342][Assigned] IO.readlines ignores Encoding.default_internal if Encoding.default_external is ASCII-8BIT


Issue #8342 has been updated by nobu (Nobuyoshi Nakada).

Category set to M17N
Status changed from Open to Assigned
Assignee set to naruse (Yui NARUSE)
Target version set to current: 2.1.0

Seems intended behavior to me.
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Bug #8342: IO.readlines ignores Encoding.default_internal if Encoding.default_external is ASCII-8BIT
https://bugs.ruby-lang.org/issues/8342#change-39021

Author: leocassarani (Leo Cassarani)
Status: Assigned
Priority: Normal
Assignee: naruse (Yui NARUSE)
Category: M17N
Target version: current: 2.1.0
ruby -v: 1.9.3
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


Under normal circumstances, IO.readlines will transcode from Encoding.default_external to Encoding.default_internal:

File.open('hi', 'w') { |f| f.puts "hello\n" }
Encoding.default_external = Encoding::US_ASCII
Encoding.default_internal = Encoding::UTF_8
puts IO.readlines('hi').first.encoding
#=> UTF-8

However, when Encoding.default_external is set to ASCII-8BIT, IO.readlines will always use ASCII-8BIT, regardless of what Encoding.default_internal is set to:

File.open('hi', 'w') { |f| f.puts "hello\n" }
Encoding.default_external = Encoding::ASCII_8BIT
Encoding.default_internal = Encoding::UTF_8
puts IO.readlines('hi').first.encoding
#=> ASCII-8BIT

Using IO#gets instead of IO.readlines will produce the same behaviour.


-- 
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