Add possible overriding of builtin cli cmds

flask/cli.py

@@ -336,15 +336,15 @@ class FlaskGroup(AppGroup):
         #
         # This also means that the script stays functional in case the
         # application completely fails.
-        rv = AppGroup.get_command(self, ctx, name)
-        if rv is not None:
-            return rv
+        builtin_rv = AppGroup.get_command(self, ctx, name)
 
         info = ctx.ensure_object(ScriptInfo)
         try:
             rv = info.load_app().cli.get_command(ctx, name)
             if rv is not None:
                 return rv
+            elif builtin_rv is not None:
+                return builtin_rv
         except NoAppException:
             pass
 

tests/test_cli.py

@@ -190,3 +190,16 @@ def test_flaskgroup():
     result = runner.invoke(cli, ['test'])
     assert result.exit_code == 0
     assert result.output == 'flaskgroup\n'
+
+def test_override_builtin_cli():
+    cli = FlaskGroup(create_app=lambda info: Flask('override_builtin'))
+
+    @cli.command('run', help="foo")
+    def run():
+        click.echo(current_app.name)
+
+    runner = CliRunner()
+    result = runner.invoke(cli, ['run'])
+    assert result.exit_code == 0
+    assert result.output == 'override_builtin\n'
+