child_process customFds broken

[isaacs]

Script: https://gist.github.com/1214279

Expected 0.4 behavior: open vim as a child process of node.

Actual: node freezes without any output

[piscisaureus]

@isaacs

Is customFds ever used for anything other than passing [0, 1, 2] ?

[isaacs]

@piscisaureus Yeah, if you want to pipe a child process's stdout and stderr to the same log file, you'd pass in the fd of that log file, and -1 to use the default child proc's stdin. So, it'd be something like [-1, fd, fd].

Of course, we'll need some kind of cross-platform API for this, but I'm not sure what that would look like. In the meantime, supporting customFds as-is on unix would be good.