test: put tty in blocking mode after test

Tests can leave the tty in non-blocking mode. If the test runner tries
to print to stdout/stderr after that and the tty buffer is full, it'll
die with a EAGAIN OSError. Ergo, put the tty back in blocking mode
before proceeding.

1 files changed, 11 insertions, 1 deletions

diff --git a/tools/test.py b/tools/test.py
index e94ad24f83..29e850dacb 100755
--- a/tools/test.py
+++ b/tools/test.py
@@ -400,10 +400,20 @@ class TestCase(object):
 
   def Run(self):
     self.BeforeRun()
+
     try:
       result = self.RunCommand(self.GetCommand())
     finally:
-      self.AfterRun(result)
+      # Tests can leave the tty in non-blocking mode. If the test runner
+      # tries to print to stdout/stderr after that and the tty buffer is
+      # full, it'll die with a EAGAIN OSError. Ergo, put the tty back in
+      # blocking mode before proceeding.
+      if sys.platform != 'win32':
+        from fcntl import fcntl, F_GETFL, F_SETFL
+        from os import O_NONBLOCK
+        for fd in 0,1,2: fcntl(fd, F_SETFL, ~O_NONBLOCK & fcntl(fd, F_GETFL))
+
+    self.AfterRun(result)
     return result
 
   def Cleanup(self):