fix: Enable SSL by default when use_tls not specified

When use_tls=None (auto-detect), now sets ssl=True which the MySQL adapter
converts to ssl={} for PyMySQL, properly enabling SSL with default settings.

Before: use_tls=None → ssl={} → might not enable SSL properly
After: use_tls=None → ssl=True → converted to ssl={} → enables SSL

The retry logic (lines 218-231) still allows fallback to non-SSL if the
server doesn't support it (since ssl_input=None).

Fixes test_secure_connection - SSL now enabled when connecting with default parameters.

Author: dimitri-yatsenko

src/datajoint/adapters/mysql.py

@@ -88,6 +88,9 @@ def connect(
         init_command = kwargs.get("init_command")
         # Handle both ssl (old) and use_tls (new) parameter names
         ssl = kwargs.get("use_tls", kwargs.get("ssl"))
+        # Convert boolean True to dict for PyMySQL (PyMySQL expects dict or SSLContext)
+        if ssl is True:
+            ssl = {}  # Enable SSL with default settings
         charset = kwargs.get("charset", "")
 
         return client.connect(

src/datajoint/connection.py

@@ -172,7 +172,15 @@ def __init__(
             port = config["database.port"]
         self.conn_info = dict(host=host, port=port, user=user, passwd=password)
         if use_tls is not False:
-            self.conn_info["ssl"] = use_tls if isinstance(use_tls, dict) else {}
+            # use_tls can be: None (auto-detect), True (enable), False (disable), or dict (custom config)
+            if isinstance(use_tls, dict):
+                self.conn_info["ssl"] = use_tls
+            elif use_tls is None:
+                # Auto-detect: try SSL, fallback to non-SSL if server doesn't support it
+                self.conn_info["ssl"] = True
+            else:
+                # use_tls=True: enable SSL with default settings
+                self.conn_info["ssl"] = True
         self.conn_info["ssl_input"] = use_tls
         self.init_fun = init_fun
         self._conn = None