Let's no deprecate the attribute function yet

doc/deprecated.rst

@@ -11,9 +11,8 @@ Functions
 * The ``twig_test_iterable`` function is deprecated; use the native PHP
   ``is_iterable`` function instead.
 
-* The ``attribute`` function is deprecated as of Twig 3.15 and will be removed
-  in Twig 4.0. Use the ``.`` operator instead and wrap the name with
-  parenthesis:
+* The ``attribute`` function is deprecated as of Twig 3.15. Use the ``.``
+  operator instead and wrap the name with parenthesis:
 
   .. code-block:: twig
 
@@ -27,6 +26,8 @@ Functions
     {{ object.(method)(arguments) }}
     {{ array[item] }}
 
+  Note that it won't be removed in 4.0 to allow a smoother upgrade path.
+
 Extensions
 ----------
 

doc/functions/attribute.rst

@@ -5,6 +5,8 @@
 
     The ``attribute`` filter is deprecated as of Twig 3.15. Use the ``.``
     operator that now accepts any expression when wrapped with parenthesis.
+    Note that this filter will still be available in Twig 4.0 to allow a
+    smoother upgrade path.
 
 The ``attribute`` function can be used to access a "dynamic" attribute of a
 variable:

src/Extension/CoreExtension.php

@@ -1966,11 +1966,14 @@ final class CoreExtension extends AbstractExtension
         $fakeFunction = new TwigFunction('attribute', fn ($variable, $attribute, $arguments = null) => null);
         $args = (new CallableArgumentsExtractor($fakeNode, $fakeFunction))->extractArguments($args);
 
+        /*
+        Deprecation to uncomment sometimes during the lifetime of the 4.x branch
         $src = $parser->getStream()->getSourceContext();
         $dep = new DeprecatedCallableInfo('twig/twig', '3.15', 'The "attribute" function is deprecated, use the "." notation instead.');
         $dep->setName('attribute');
         $dep->setType('function');
         $dep->triggerDeprecation($src->getPath() ?: $src->getName(), $line);
+        */
 
         return new GetAttrExpression($args[0], $args[1], $args[2] ?? null, Template::ANY_CALL, $line);
     }

tests/Fixtures/functions/attribute.legacy.test

@@ -1,16 +1,5 @@
 --TEST--
 "attribute" function
---DEPRECATION--
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 2.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 3.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 4.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 5.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 6.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 7.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 8.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 9.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 10.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 11.
 --TEMPLATE--
 {{ attribute(obj, method) }}
 {{ attribute(variable=obj, attribute=method) }}

tests/Fixtures/tests/defined_for_attribute.legacy.test

@@ -1,10 +1,5 @@
 --TEST--
 "defined" support for attribute
---DEPRECATION--
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 2.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 3.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 4.
-Since twig/twig 3.15: Twig Function "attribute" is deprecated; use "The "attribute" function is deprecated, use the "." notation instead." instead in index.twig at line 5.
 --TEMPLATE--
 {{ attribute(nested, "definedVar")     is     defined ? 'ok' : 'ko' }}
 {{ attribute(nested, "undefinedVar")   is not defined ? 'ok' : 'ko' }}