bpo-36629: Add support.get_socket_conn_refused_errs() (GH-12834)

Fix test_imap4_host_default_value() of test_imaplib: catch also
errno.ENETUNREACH error.

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index 5bd15a2..2bb561b 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -1477,6 +1477,22 @@ socket_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)
 ioerror_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)
 
 
+def get_socket_conn_refused_errs():
+    """
+    Get the different socket error numbers ('errno') which can be received
+    when a connection is refused.
+    """
+    errors = [errno.ECONNREFUSED]
+    if hasattr(errno, 'ENETUNREACH'):
+        # On Solaris, ENETUNREACH is returned sometimes instead of ECONNREFUSED
+        errors.append(errno.ENETUNREACH)
+    if hasattr(errno, 'EADDRNOTAVAIL'):
+        # bpo-31910: socket.create_connection() fails randomly
+        # with EADDRNOTAVAIL on Travis CI
+        errors.append(errno.EADDRNOTAVAIL)
+    return errors
+
+
 @contextlib.contextmanager
 def transient_internet(resource_name, *, timeout=30.0, errnos=()):
     """Return a context manager that raises ResourceDenied when various issues