[9fans] APE select() and awkward Python subprocess PIPEfitting

[Jeff Sickel <jas@corpus-callosum.com>]

I've been tracking down little errors in the APE select() function that cropped up when trying to use Python's subprocess module.  After a few too many hours of investigation, I've come to the conclusion that the code that causes error is intentional code to handle a specific case for X (I'll assume X11 until corrected):

; diff /sys/src/ape/lib/ap/plan9/_buf.c _buf.c
292a293
> printf("no buffered %d\n", i);
294a296
> /*
298c300
< 				errno = EBADF;		/* how X tells a client is gone */
---
> 				errno = EBADF;		// how X tells a client is gone
300a303
> */



By removing the above, Python code that uses subprocess.Popen(cmd, stdout=PIPE, stderr=PIPE) will now work correctly, without having to resort to os.popen3(cmd) attempts to get around the select.error: (4, 'Bad file number') that would crop up without the change.

My question is: does anyone still use the X11 code based on APE?  Is this section safe to remove in sources?  Or do you have additional recommendations to work around the select() error?

If not, I'll prep a patch.  Thanks.

-jas