Improve handling of empty lists

With this change users will get a psr/log warning instead of the PHP
Warning they were getting before.

packages/guides-restructured-text/src/RestructuredText/Parser/Productions/ListRule.php

@@ -22,6 +22,7 @@
 use phpDocumentor\Guides\RestructuredText\Parser\Buffer;
 use phpDocumentor\Guides\RestructuredText\Parser\DocumentParserContext;
 use phpDocumentor\Guides\RestructuredText\Parser\LinesIterator;
+use Psr\Log\LoggerInterface;
 
 use function count;
 use function ltrim;
@@ -55,8 +56,10 @@ final class ListRule implements Rule
          # (or eol, if text starts on a new line)
         /ux';
 
-    public function __construct(private readonly RuleContainer $productions)
-    {
+    public function __construct(
+        private readonly RuleContainer $productions,
+        private readonly LoggerInterface $logger,
+    ) {
     }
 
     public function applies(DocumentParserContext $documentParser): bool
@@ -168,6 +171,12 @@ private function parseListItem(array $listConfig, Buffer $buffer, DocumentParser
             return $listItem;
         }
 
+        if (!isset($nodes[0])) {
+            $this->logger->warning('List item without content');
+
+            return $listItem;
+        }
+
         // the list item offset is determined by the offset of the first text
         if ($nodes[0] instanceof ParagraphNode) {
             return new ListItemNode($listConfig['marker'], false, $nodes[0]->getChildren());

packages/guides-restructured-text/tests/unit/Parser/Productions/ListRuleTest.php

@@ -8,6 +8,7 @@
 use phpDocumentor\Guides\Nodes\ListNode;
 use phpDocumentor\Guides\Nodes\RawNode;
 use PHPUnit\Framework\Attributes\DataProvider;
+use Psr\Log\NullLogger;
 
 final class ListRuleTest extends RuleTestCase
 {
@@ -16,7 +17,7 @@ final class ListRuleTest extends RuleTestCase
     protected function setUp(): void
     {
         $ruleContainer = $this->givenCollectAllRuleContainer();
-        $this->rule = new ListRule($ruleContainer);
+        $this->rule = new ListRule($ruleContainer, new NullLogger());
     }
 
     #[DataProvider('startChars')]

tests/Functional/tests/empty-list/empty-list.html

@@ -0,0 +1,3 @@
+<ul>
+    <li></li>
+</ul>

tests/Functional/tests/empty-list/empty-list.log

@@ -0,0 +1 @@
+WARNING: List item without content

tests/Functional/tests/empty-list/empty-list.rst

@@ -0,0 +1 @@
+*