Say (accept-process-output P)'s result pertains to P if P is non-nil.

* doc/lispref/processes.texi (Accepting Output):
* src/process.c (Faccept_process_output)
(wait_reading_process_output): Mention that if PROCESS is non-nil,
the return value is about PROCESS, not about other processes.

2 files changed, 9 insertions, 2 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index 93128962c33..d859e0f01a9 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Say (accept-process-output P)'s result pertains to P if P is non-nil.
+        * processes.texi (Accepting Output): Mention that if PROCESS is non-nil,
+        the return value is about PROCESS, not about other processes.
+
 2014-06-08  Glenn Morris  <rgm@gnu.org>
 
         * os.texi (Startup Summary): Small fix for initial-buffer-choice.
diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi
index c91afdffdeb..db80f0537e0 100644
--- a/doc/lispref/processes.texi
+++ b/doc/lispref/processes.texi
@@ -1484,7 +1484,7 @@ The arguments @var{seconds} and @var{millisec} let you specify timeout
 periods.  The former specifies a period measured in seconds and the
 latter specifies one measured in milliseconds.  The two time periods
 thus specified are added together, and @code{accept-process-output}
-returns after that much time, whether or not there has been any
+returns after that much time, even if there is no
 subprocess output.
 
 The argument @var{millisec} is obsolete (and should not be used),
@@ -1502,7 +1502,8 @@ recommended, but may be necessary for specific applications, such as
 speech synthesis.
 
 The function @code{accept-process-output} returns non-@code{nil} if it
-did get some output, or @code{nil} if the timeout expired before output
+got output from @var{process}, or from any process if @var{process} is
+@code{nil}.  It returns @code{nil} if the timeout expired before output
 arrived.
 @end defun