Bug #8445: IO.open and IO#set_enconding does not support :fallback option

[Haruhiro Yoshimoto]

RubyDoc says that IO.open and IO#set_encoding supports optional argument defined in String#encode.
http://ruby-doc.org/core-2.0/IO.html#method-c-new-label-Options
In fact, :invalid, :undef and :replace works as expected.

However, :fallback option does not work neither for IO.open and IO#set_encoding.
Following is the example code which does not work.
f(x) is never called even if hoge.txt contains non convertible character.

File.open("./hoge.txt","r:ShiftJIS:utf-8", :fallback => lambda{|x|f(x)}){|f|
...
}
File.open("./hoge.txt"){|f|
f.setencoding("Shift_JIS","utf-8",:fallback => lambda{|x|f(x)})
...
}

I Think this is because fillcbuf() in io.c calls rbeconvconvert() from transcode.c directly.
On the other hand, fallbackfunc is called in transcodeloop(), which is called by strencode().

Since transcodeloop() also calls rbeconvconvert(), I wrote a small patch which moves some codes from
transcodeloop() to rbeconvconvert() to fix the problem.

The attached file is the patch. Hope this helps.

[Yui NARUSE]

• Category set to M17N
• Status changed from Open to Assigned
• Assignee set to Akira Tanaka
• Target version set to 2.1.0

Is this intentional or just unexpected inconsistency?

[Hiroshi SHIBATA]

• Target version changed from 2.1.0 to current: 2.2.0