bpo-30418: Popen.communicate() always ignore EINVAL (#2002) (#2006)

On Windows, subprocess.Popen.communicate() now also ignore EINVAL
on stdin.write() if the child process is still running but closed the
pipe.
(cherry picked from commit d52aa31378ae43e044a300edfe8285954c167216)

2 files changed, 8 insertions, 4 deletions

diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index c6ecc46..4b41f5e 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -720,10 +720,11 @@ class Popen(object):
                         if e.errno == errno.EPIPE:
                             # communicate() should ignore broken pipe error
                             pass
-                        elif (e.errno == errno.EINVAL
-                              and self.poll() is not None):
-                            # Issue #19612: stdin.write() fails with EINVAL
-                            # if the process already exited before the write
+                        elif e.errno == errno.EINVAL:
+                            # bpo-19612, bpo-30418: On Windows, stdin.write()
+                            # fails with EINVAL if the child process exited or
+                            # if the child process is still running but closed
+                            # the pipe.
                             pass
                         else:
                             raise
diff --git a/Misc/NEWS b/Misc/NEWS
index 12280bd..914ac89 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -49,6 +49,9 @@ Extension Modules
 Library
 -------
 
+- bpo-30418: On Windows, subprocess.Popen.communicate() now also ignore EINVAL
+  on stdin.write() if the child process is still running but closed the pipe.
+
 - bpo-30378: Fix the problem that logging.handlers.SysLogHandler cannot
   handle IPv6 addresses.