Merge branch '3.x' into 4.x

* 3.x:
  Clarify the exception message for nested block chains from another environment
  Report a clear error when using macros imported in a template body that was not rendered

# Conflicts:
#	CHANGELOG
#	src/Template.php
#	tests/CallMacroTest.php

src/BlockChain.php

@@ -44,7 +44,7 @@ final class BlockChain
         foreach ($templates as $template) {
             if ($template instanceof self) {
                 if ($env !== $template->env) {
-                    throw new \LogicException('A block chain cannot contain templates from different Twig environments.');
+                    throw new \LogicException('A block chain cannot contain a block chain from a different Twig environment.');
                 }
 
                 $this->templates[] = $template;

src/Node/Expression/Variable/MacroVariable.php

@@ -52,9 +52,11 @@ class MacroVariable extends AbstractExpression
             $compiler->raw('$this->getMacroNamespace()');
         } else {
             $compiler
-                ->raw('$macros[')
+                ->raw('($macros[')
                 ->string($name)
-                ->raw(']')
+                ->raw('] ?? $this->throwUninitializedMacroNamespace(')
+                ->repr($this->getTemplateLine())
+                ->raw('))')
             ;
         }
     }

src/Template.php

@@ -486,6 +486,14 @@ abstract class Template
     {
     }
 
+    /**
+     * @internal
+     */
+    protected function throwUninitializedMacroNamespace(int $line): never
+    {
+        throw new RuntimeError(\sprintf('Macros imported in the body of template "%s" are not available because the body was not rendered; move the "import" or "from" tag inside the block or the macro that uses it.', $this->getTemplateName()), $line, $this->getSourceContext());
+    }
+
     private function handleException(\Throwable $error): never
     {
         if ($error instanceof Error) {

tests/BlockChainTest.php

@@ -296,7 +296,7 @@ class BlockChainTest extends TestCase
         $other = new Environment(new ArrayLoader(['theme' => '']));
 
         $this->expectException(\LogicException::class);
-        $this->expectExceptionMessage('A block chain cannot contain templates from different Twig environments.');
+        $this->expectExceptionMessage('A block chain cannot contain a block chain from a different Twig environment.');
 
         new BlockChain($twig, [new BlockChain($other, ['theme'])]);
     }
@@ -519,7 +519,8 @@ class BlockChainTest extends TestCase
         try {
             $chain->renderBlock('field', ['helper' => 'macros1']);
             $this->fail('Rendering an uninitialized import must fail.');
-        } catch (RuntimeError) {
+        } catch (RuntimeError $e) {
+            $this->assertStringContainsString('Macros imported in the body of template "theme" are not available because the body was not rendered', $e->getMessage());
         }
 
         $this->assertSame('one', $twig->render('theme', ['helper' => 'macros1']));

tests/CallMacroTest.php

@@ -134,6 +134,42 @@ class CallMacroTest extends TestCase
         $template->getMacroNamespace()->call('missing', [], [], 1, new Source('', 'index'));
     }
 
+    public function testRenderingABlockOnItsOwnReportsMacrosImportedInTheTemplateBody(): void
+    {
+        $template = $this->load([
+            'index' => '{% import "macros" as helpers %}{% block field %}{{ helpers.label() }}{% endblock %}',
+            'macros' => '{% macro label() %}label{% endmacro %}',
+        ]);
+
+        $this->expectException(RuntimeError::class);
+        $this->expectExceptionMessage('Macros imported in the body of template "index" are not available because the body was not rendered; move the "import" or "from" tag inside the block or the macro that uses it in "index" at line 1.');
+
+        $template->renderBlock('field', []);
+    }
+
+    public function testRenderingABlockOnItsOwnUsesMacrosImportedInTheBlock(): void
+    {
+        $template = $this->load([
+            'index' => '{% block field %}{% import "macros" as helpers %}{{ helpers.label() }}{% endblock %}',
+            'macros' => '{% macro label() %}label{% endmacro %}',
+        ]);
+
+        $this->assertSame('label', $template->renderBlock('field', []));
+    }
+
+    public function testCallingAMacroOnItsOwnReportsMacrosImportedInTheTemplateBody(): void
+    {
+        $template = $this->load([
+            'index' => '{% from "macros" import label %}{% macro row() %}{{ label() }}{% endmacro %}',
+            'macros' => '{% macro label() %}label{% endmacro %}',
+        ]);
+
+        $this->expectException(RuntimeError::class);
+        $this->expectExceptionMessage('Macros imported in the body of template "index" are not available because the body was not rendered');
+
+        $this->callMacro($template, 'row', []);
+    }
+
     private function callMacro(Template $template, string $name, array $arguments): mixed
     {
         return $template->getMacroNamespace()->call($name, $arguments, [], 1, new Source('', 'index'));