Bug #16422: IO#set_encoding_by_bom when encoding is already set

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.5: UNKNOWN, 2.6: UNKNOWN

[zverok (Victor Shepelev)]

IO#set_encoding_by_bom docs say:

If ios is not binmode or its encoding has been set already, an exception will be raised.

In reality this does not happen (or I don't understand the meaning of bold statement above):

File.write("tmp/bom.txt", "\u{FEFF}мама")
ios = File.open("tmp/bom.txt", "rb", encoding: 'Windows-1251')
ios.external_encoding
# => #<Encoding:Windows-1251>
ios.set_encoding_by_bom
# => #<Encoding:UTF-8>
ios.external_encoding
# => #<Encoding:UTF-8>

...though in code, seems that error should be raised.

I wonder if it is an error in docs, bug in code, or just my misunderstanding?..

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|e8c62836a6292bf2f691de458b24ea50c51b452a.

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IO#set_encoding_by_bom should err when encoding is already set

Except for ASCII-8BIT. [Bug #16422]