Fix AttributeError in az extension update when extension has missing metadata from partial install

src/azure-cli-core/azure/cli/core/extension/__init__.py

@@ -129,7 +129,7 @@ def __init__(self, name, path=None):
         super().__init__(name, 'whl', path)
 
     def get_version(self):
-        return self.metadata.get('version')
+        return self.metadata.get('version') if self.metadata else None
 
     def get_metadata(self):
         from glob import glob
@@ -210,7 +210,7 @@ def __init__(self, name, path):
         super().__init__(name, 'dev', path)
 
     def get_version(self):
-        return self.metadata.get('version')
+        return self.metadata.get('version') if self.metadata else None
 
     def get_metadata(self):
         import pkginfo

src/azure-cli-core/azure/cli/core/extension/operations.py

@@ -407,6 +407,9 @@ def update_extension(cmd=None, extension_name=None, index_url=None, pip_extra_in
             raise CLIError(
                 f"Cannot update system extension {extension_name}, please wait until Cloud Shell updates it in the next release.")
         cur_version = ext.get_version()
+        if cur_version is None:
+            logger.warning("The '%s' extension has missing or invalid metadata. It may have been partially installed. "
+                           "Proceeding with update to attempt to repair it.", extension_name)
         try:
             if not download_url:
                 download_url, ext_sha256 = resolve_from_index(extension_name, cur_version=cur_version, index_url=index_url, target_version=version, cli_ctx=cmd_cli_ctx, allow_preview=allow_preview)
@@ -435,7 +438,7 @@ def update_extension(cmd=None, extension_name=None, index_url=None, pip_extra_in
             logger.error(err)
             logger.debug('Copying %s to %s', backup_dir, extension_path)
             shutil.copytree(backup_dir, extension_path)
-            raise CLIError('Failed to update. Rolled {} back to {}.'.format(extension_name, cur_version))
+            raise CLIError('Failed to update. Rolled {} back to {}.'.format(extension_name, cur_version or 'unknown'))
         CommandIndex().invalidate()
     except ExtensionNotInstalledException as e:
         raise CLIError(e)

src/azure-cli-core/azure/cli/core/tests/test_extension.py

@@ -455,6 +455,37 @@ def test_update_extension_with_preview(self):
             self.assertEqual(ext['name'], extension_name)
             self.assertEqual(ext['version'], '1.4.1a1')
 
+    def test_update_extension_with_corrupted_metadata(self):
+        """Test that update_extension works when extension has missing/corrupted metadata (partial install)."""
+        extension_name = "extension-test-pkg"
+        extension2 = 'extension_test_pkg-1.2.3-py3-none-any.whl'
+
+        mocked_index_data = {
+            extension_name: [
+                mock_ext(extension2, version='1.2.3', download_url=_get_test_data_file(extension2)),
+            ]
+        }
+        with mock.patch('azure.cli.core.extension._resolve.get_index_extensions',
+                        return_value=mocked_index_data):
+            add_extension(self.cmd, extension_name=extension_name)
+            ext = show_extension(extension_name)
+            self.assertEqual(ext['name'], extension_name)
+            self.assertEqual(ext['version'], '1.2.3')
+
+            # Simulate corrupted/partial install by patching get_version to return None
+            with mock.patch('azure.cli.core.extension.operations.logger') as mock_logger:
+                with mock.patch.object(WheelExtension, 'get_version', return_value=None):
+                    update_extension(self.cmd, extension_name)
+
+                # Verify the warning about missing metadata was emitted
+                warning_messages = [str(call) for call in mock_logger.warning.call_args_list]
+                self.assertTrue(any(extension_name in msg for msg in warning_messages))
+
+            # Verify the extension was successfully repaired/updated
+            ext = show_extension(extension_name)
+            self.assertEqual(ext['name'], extension_name)
+            self.assertEqual(ext['version'], '1.2.3')
+
     @mock.patch('sys.stdin.isatty', return_value=True)
     def test_ext_dynamic_install_config_tty(self, _):
         from azure.cli.core.extension.dynamic_install import _get_extension_use_dynamic_install_config
@@ -497,6 +528,12 @@ def test_wheel_metadata2(self):
         # We check that we can retrieve any one of the az extension metadata values
         self.assertTrue(ext.metadata.get(EXT_METADATA_MINCLICOREVERSION))
 
+    def test_wheel_get_version_with_none_metadata(self):
+        """Test that get_version() returns None when metadata is None (e.g. corrupted/partial installation)."""
+        ext = WheelExtension(EXT_NAME)
+        with mock.patch.object(type(ext), 'metadata', new_callable=mock.PropertyMock, return_value=None):
+            self.assertIsNone(ext.get_version())
+
 
 class TestWheelSystemExtension(TestExtensionsBase):