fix: Plugin.__del__ should also free compiled_plugin when owned

When Plugin creates its own CompiledPlugin internally, it should also
free it in __del__. Added _owns_compiled_plugin flag to track ownership
and avoid freeing externally-passed CompiledPlugin instances.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: acoroleu-tempus

.gitignore

@@ -4,3 +4,4 @@ poetry-installer-error-*.log
 docs/_build
 .DS_Store
 dist/
+.idea/

extism/extism.py

@@ -551,7 +551,9 @@ def __init__(
         config: Optional[Any] = None,
         functions: Optional[List[Function]] = HOST_FN_REGISTRY,
     ):
-        if not isinstance(plugin, CompiledPlugin):
+        # Track if we created the CompiledPlugin (so we know to free it)
+        self._owns_compiled_plugin = not isinstance(plugin, CompiledPlugin)
+        if self._owns_compiled_plugin:
             plugin = CompiledPlugin(plugin, wasi, functions)
 
         self.compiled_plugin = plugin
@@ -629,6 +631,10 @@ def __del__(self):
             return
         _lib.extism_plugin_free(self.plugin)
         self.plugin = -1
+        # Free the compiled plugin if we created it
+        if getattr(self, "_owns_compiled_plugin", False) and self.compiled_plugin is not None:
+            self.compiled_plugin.__del__()
+            self.compiled_plugin = None
 
     def __enter__(self):
         return self

tests/test_extism.py

@@ -64,10 +64,15 @@ def test_plugin_del_frees_native_resources(self):
         with extism.Plugin(self._manifest(), functions=[]) as plugin:
             j = json.loads(plugin.call("count_vowels", "test"))
             self.assertEqual(j["count"], 1)
+            # Plugin should own the compiled plugin it created
+            self.assertTrue(plugin._owns_compiled_plugin)
 
         # Verify plugin was freed after exiting context
         self.assertEqual(plugin.plugin, -1, 
             "Expected plugin.plugin to be -1 after __del__, indicating extism_plugin_free was called")
+        # Verify compiled plugin was also freed (since Plugin owned it)
+        self.assertIsNone(plugin.compiled_plugin,
+            "Expected compiled_plugin to be None after __del__, indicating it was also freed")
 
     def test_compiled_plugin_del_frees_native_resources(self):
         """Test that CompiledPlugin.__del__ properly frees native resources.
@@ -86,11 +91,18 @@ def test_compiled_plugin_del_frees_native_resources(self):
         j = json.loads(plugin.call("count_vowels", "test"))
         self.assertEqual(j["count"], 1)
 
+        # Plugin should NOT own the compiled plugin (it was passed in)
+        self.assertFalse(plugin._owns_compiled_plugin)
+        
         # Clean up plugin first
         plugin.__del__()
         self.assertEqual(plugin.plugin, -1)
 
-        # Now clean up compiled plugin
+        # Compiled plugin should NOT have been freed by Plugin.__del__
+        self.assertNotEqual(compiled.pointer, -1,
+            "Expected compiled.pointer to NOT be -1 since Plugin didn't own it")
+        
+        # Now clean up compiled plugin manually
         compiled.__del__()
 
         # Verify compiled plugin was freed