Before filing a bug, please check whether it has been fixed since the
latest release. Search the issue tracker and check that you're running the
latest version of Go:

Run "go version" and compare against
http://golang.org/doc/devel/release.html  If a newer version of Go exists,
install it and retry what you did to reproduce the problem.

Thanks.

What steps will reproduce the problem?
If possible, include a link to a program on play.golang.org.
1. Compile the program from http://play.golang.org/p/bcmX4--v_j on Windows 7
2. Run the resulting program on Windows 7
3. Press a key, then hit enter

What is the expected output?
It should copy the input from stdin to stdout

What do you see instead?
0 read /dev/stdin: Not enough storage is available to process this command.

Which compiler are you using (5g, 6g, 8g, gccgo)?
8g

Which operating system are you using?
Windows 7

Which version are you using?  (run 'go version')
go version devel +8f1fb6b6f141 Mon May 13 13:04:08 2013 -0700 linux/amd64 (cross
compiled, natively compiling has the same effect)

Please provide any additional information below.
The problem here is that io.Copy uses a buffer that is 32KB big. Since we're copying
from stdin on Windows, the Read operation runs through (*File).readConsole
(os/file_windows.go), which uses the ReadConsole syscall. Due to wchars, readConsole
uses a buffer twice the size of the original one, so 64KB in this case. ReadConsole is
documented[1] to accept at most a 64K buffer, possibly less. For some reason, it fails
on exactly 64KB, which might be an error in the documentation, caused by already used
heap, or a bug (the comments below the documentation would suggest so).

I also assembled a longer Go program[2] that demonstrates that the issue boils down to
the buffer size, where it works for 2^15-1 bytes but not for 2^15.

I'm filing this as an issue on io.Copy because I'm not sure that the issue (a limited
Windows API) can be fixed in a broader scope.

[1] http://msdn.microsoft.com/en-us/library/windows/desktop/ms684958(v=vs.85)
[2] http://play.golang.org/p/tWnZuyZLPV