Bug #3014: select + read for STDIN unexpected result on Windows

• Status: Closed
• Assignee: usa (Usaku NAKAMURA)
• Target version: 1.9.2
• ruby -v: ruby 1.9.2dev (2010-03-26 trunk 27048) [i386-mswin32_90]

[phasis68 (Heesob Park)]

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I found that select and read combination for STDIN results "r u b y . e x e" on Windows.

Consider following code:
select([STDIN],nil,nil,10);puts STDIN.read(8)

I entered "test1234\n" for input.

On 1.8.6, it works fine.

C:>ruby -ve 'select([STDIN],nil,nil,10);puts STDIN.read(8)'
ruby 1.8.6 (2010-02-04 patchlevel 398) [i386-mingw32]
test1234
test1234

On 1.9.x, it results "r u b y".

C:\work>ruby -ve 'select([STDIN],nil,nil,10);puts STDIN.read(8)'
ruby 1.9.1p129 (2009-05-12 revision 23412) [i386-mingw32]
test1234
r u b y

C:\work>ruby -ve 'select([STDIN],nil,nil,10);puts STDIN.read(8)'
ruby 1.9.2dev (2010-03-26 trunk 27048) [i386-mswin32_90]
test1234
r u b y

C:\work>ruby -ve 'select([STDIN],nil,nil,10);p STDIN.read(8)'
ruby 1.9.2dev (2010-03-26 trunk 27048) [i386-mswin32_90]
test1234
"r\x00u\x00b\x00y\x00"

The result string is actually "r u b y . e x e" plus some garbage.
=end

[yugui (Yuki Sonoda)]

• Assignee set to usa (Usaku NAKAMURA)
• Target version changed from 2.0.0 to 1.9.2

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=end

[phasis68 (Heesob Park)]

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I found that STDIN.read(n) works when n >= 41.

I guess this bug is caused by PeekConsoleInput's bug or side effect.

Here is a guick and dirty patch.

--- win32.c 2010-03-26 19:04:28.502025030 +0900
+++ win32.c.new 2010-03-26 19:03:05.138310126 +0900
@@ -4851,6 +4851,10 @@
return _read(fd, buf, size);
}

• if((_osfile(fd) & FDEV) && size <= 40) {

•   return fread(buf, 1, size, stdin);
  

• }

• MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fd)->lock)));

  if (!size || _osfile(fd) & FEOFLAG) {

=end

[usa (Usaku NAKAMURA)]

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

=begin
This issue was solved with changeset r28035.
Heesob, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

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