Bug #8625: IO#read(len, buf) shortens buf even if data is not read actually

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: -
• ruby -v: ruby 2.1.0dev (2013-07-11 trunk 41923) [x86_64-linux]
• Backport: 2.0.0: DONE, 2.1: DONE

[no6v (Nobuhiro IMAI)]

By r34580, IO#read(len, buf) does not expand buf until data is read actually,
but it still shortens if the original buf size is greater than len.
Is this an intended behavior?

def m(s)
  IO.pipe do |r, w|
    t = Thread.new{r.read(2, s)}
    Thread.pass until t.stop?
    t.kill
    t.value
  end
end

(1..3).each do |len|
  s = "x" * len
  s # => "x", "xx", "xxx"
  m(s)
  s # => "x", "xx", "xx"
end

[Glass_saga (Masaki Matsushita)]

• Status changed from Open to Assigned
• Assignee set to nobu (Nobuyoshi Nakada)

Nakada-san, what do you think?

[Glass_saga (Masaki Matsushita)]

• Assignee changed from nobu (Nobuyoshi Nakada) to Glass_saga (Masaki Matsushita)

[nobu (Nobuyoshi Nakada)]

• Backport changed from 1.9.3: UNKNOWN, 2.0.0: UNKNOWN to 2.0.0: REQUIRED, 2.1: REQUIRED
• Description updated (diff)

[nobu (Nobuyoshi Nakada)]

• % Done changed from 0 to 100
• Status changed from Assigned to Closed

Applied in changeset r46360.

---

io.c: not shorten buffer unless succeeded

• io.c (io_setstrbuf, io_read): should not shorten the given buffer until
  read succeeds. [ruby-core:55951] [Bug #8625]

[usa (Usaku NAKAMURA)]

• Status changed from Closed to Assigned
• Assignee changed from Glass_saga (Masaki Matsushita) to nobu (Nobuyoshi Nakada)

r46360 breaks some tests on mswin.

[nobu (Nobuyoshi Nakada)]

• Status changed from Assigned to Closed

Applied in changeset r46372.

---

io.c: truncate before appending

• io.c (read_all): truncate the buffer before appending read data,
  instead of truncating before reading.
  [ruby-core:55951] [Bug #8625]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: REQUIRED, 2.1: REQUIRED to 2.0.0: REQUIRED, 2.1: DONE

Backported into ruby_2_1 branch at r46629.

[usa (Usaku NAKAMURA)]

backported into ruby_2_0_0 at r46738.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: REQUIRED, 2.1: DONE to 2.0.0: DONE, 2.1: DONE