From: Ian Kelling <ian@iankelling.org>
Date: Mon, 6 Jul 2015 01:14:25 +0000 (-0700)
Subject: Avoid returning early reading process output due to SIGIO
X-Git-Tag: emacs-25.0.90~1553
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=f469c17b9c869b400b3515535b2f1fd9dd00f9a0;p=emacs.git

Avoid returning early reading process output due to SIGIO

* src/process.c (wait_reading_process_output): Extend the behavior of
not breaking due to not finding output when a timer has lowered the
timeout to include when SIGIO lowers the timeout.
---

diff --git a/src/process.c b/src/process.c
index 8e046a6dd11..8a8dad793ad 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4960,12 +4960,18 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 
       if (nfds == 0)
 	{
+          /* Exit the main loop if we've passed the requested timeout,
+             or aren't skipping processes and got some output and
+             haven't lowered our timeout due to timers or SIGIO and
+             have waited a long amount of time due to repeated
+             timers.  */
 	  struct timespec now = current_timespec ();
-	  if ((timeout.tv_sec == 0 && timeout.tv_nsec == 0)
+          if (wait < TIMEOUT
 	      || (wait == TIMEOUT && timespec_cmp (end_time, now) <= 0)
 	      || (!process_skipped && got_some_output > 0
 		  && (!timespec_valid_p (got_output_end_time)
-		      || timespec_cmp (got_output_end_time, now) <= 0)))
+		      || timespec_cmp (got_output_end_time, now) <= 0)
+		  && (timeout.tv_sec > 0 || timeout.tv_nsec > 0)))
 	    break;
 	}