Close Unix sockets if the connection attempt fails (#3315)

Make sure Unix sockets get closed if the connection fails.

Fixes #3314

CHANGES

@@ -64,6 +64,7 @@
     * Make `ClusterCommandsProtocol` an actual Protocol
     * Add `sum` to DUPLICATE_POLICY documentation of `TS.CREATE`, `TS.ADD` and `TS.ALTER`
     * Prevent async ClusterPipeline instances from becoming "false-y" in case of empty command stack (#3061)
+    * Close Unix sockets if the connection attempt fails. This prevents `ResourceWarning`s. (#3314)
 
 * 4.1.3 (Feb 8, 2022)
   * Fix flushdb and flushall (#1926)

redis/connection.py

@@ -920,7 +920,12 @@ def _connect(self):
         "Create a Unix domain socket connection"
         sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
         sock.settimeout(self.socket_connect_timeout)
-        sock.connect(self.path)
+        try:
+            sock.connect(self.path)
+        except OSError:
+            # Prevent ResourceWarnings for unclosed sockets.
+            sock.close()
+            raise
         sock.settimeout(self.socket_timeout)
         return sock