Fix print_shtab incorrectly parsed from environment variable (#726)

Author: mauvilsa

CHANGELOG.rst

@@ -12,6 +12,15 @@ The semantic versioning only considers the public API as described in
 paths are considered internals and can change in minor and patch releases.
 
 
+v4.40.1 (2025-05-??)
+--------------------
+
+Fixed
+^^^^^
+- ``print_shtab`` incorrectly parsed from environment variable (`#725
+  <https://github.com/omni-us/jsonargparse/pull/725>`__).
+
+
 v4.40.0 (2025-05-16)
 --------------------
 

jsonargparse/_actions.py

@@ -139,7 +139,9 @@ def remove(actions):
 
 
 def filter_default_actions(actions):
-    default = (_HelpAction, _ActionHelpClassPath, _ActionPrintConfig)
+    from ._completions import ShtabAction
+
+    default = (_HelpAction, _ActionHelpClassPath, _ActionPrintConfig, ShtabAction)
     if isinstance(actions, list):
         return [a for a in actions if not isinstance(a, default)]
     return {k: a for k, a in actions.items() if not isinstance(a, default)}