use the empty string instead of null as an array offset

Author: xabbuh

src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php

@@ -366,7 +366,7 @@ private function getTagVersions(array $tagsByKey, bool $persistTags): array
             (self::$saveTags)($this->tags, $newTags);
         }
 
-        while ($now > ($this->knownTagVersions[$tag = array_key_first($this->knownTagVersions)][0] ?? \INF)) {
+        while ($now > ($this->knownTagVersions[$tag = array_key_first($this->knownTagVersions) ?? ''][0] ?? \INF)) {
             unset($this->knownTagVersions[$tag]);
         }
 

src/Symfony/Component/Config/Definition/Builder/ArrayNodeDefinition.php

@@ -331,7 +331,7 @@ public function normalizeKeys(bool $bool): static
 
     public function append(NodeDefinition $node): static
     {
-        $this->children[$node->name] = $node->setParent($this);
+        $this->children[$node->name ?? ''] = $node->setParent($this);
 
         return $this;
     }

src/Symfony/Component/Console/Input/ArgvInput.php

@@ -176,7 +176,7 @@ private function parseArgument(string $token): void
         } else {
             $all = $this->definition->getArguments();
             $symfonyCommandName = null;
-            if (($inputArgument = $all[$key = array_key_first($all)] ?? null) && 'command' === $inputArgument->getName()) {
+            if (($inputArgument = $all[$key = array_key_first($all) ?? ''] ?? null) && 'command' === $inputArgument->getName()) {
                 $symfonyCommandName = $this->arguments['command'] ?? null;
                 unset($all[$key]);
             }

src/Symfony/Component/DependencyInjection/Compiler/CheckTypeDeclarationsPass.php

@@ -79,7 +79,7 @@ public function __construct(bool $autoload = false, array $skippedIds = [])
 
     protected function processValue(mixed $value, bool $isRoot = false): mixed
     {
-        if (isset($this->skippedIds[$this->currentId])) {
+        if (isset($this->skippedIds[$this->currentId ?? ''])) {
             return $value;
         }
 

src/Symfony/Component/DependencyInjection/Compiler/DefinitionErrorExceptionPass.php

@@ -69,9 +69,9 @@ protected function processValue(mixed $value, bool $isRoot = false): mixed
                 ContainerInterface::RUNTIME_EXCEPTION_ON_INVALID_REFERENCE === $value->getInvalidBehavior()
                 || ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE === $value->getInvalidBehavior()
             ) {
-                $this->sourceReferences[$targetId][$this->currentId] ??= true;
+                $this->sourceReferences[$targetId][$this->currentId ?? ''] ??= true;
             } else {
-                $this->sourceReferences[$targetId][$this->currentId] = false;
+                $this->sourceReferences[$targetId][$this->currentId ?? ''] = false;
             }
 
             return $value;
@@ -81,7 +81,7 @@ protected function processValue(mixed $value, bool $isRoot = false): mixed
             return parent::processValue($value, $isRoot);
         }
 
-        $this->erroredDefinitions[$this->currentId] = $value;
+        $this->erroredDefinitions[$this->currentId ?? ''] = $value;
 
         return parent::processValue($value);
     }

src/Symfony/Component/DependencyInjection/Compiler/InlineServiceDefinitionsPass.php

@@ -146,7 +146,7 @@ protected function processValue(mixed $value, bool $isRoot = false): mixed
 
         $this->container->log($this, \sprintf('Inlined service "%s" to "%s".', $id, $this->currentId));
         $this->inlinedIds[$id] = $definition->isPublic() || !$definition->isShared();
-        $this->notInlinedIds[$this->currentId] = true;
+        $this->notInlinedIds[$this->currentId ?? ''] = true;
 
         if ($definition->isShared()) {
             return $definition;

src/Symfony/Component/DependencyInjection/Compiler/ResolveBindingsPass.php

@@ -121,10 +121,10 @@ protected function processValue(mixed $value, bool $isRoot = false): mixed
         foreach ($bindings as $key => $binding) {
             [$bindingValue, $bindingId, $used, $bindingType, $file] = $binding->getValues();
             if ($used) {
-                $this->usedBindings[$bindingId] = true;
-                unset($this->unusedBindings[$bindingId]);
-            } elseif (!isset($this->usedBindings[$bindingId])) {
-                $this->unusedBindings[$bindingId] = [$key, $this->currentId, $bindingType, $file];
+                $this->usedBindings[$bindingId ?? ''] = true;
+                unset($this->unusedBindings[$bindingId ?? '']);
+            } elseif (!isset($this->usedBindings[$bindingId ?? ''])) {
+                $this->unusedBindings[$bindingId ?? ''] = [$key, $this->currentId, $bindingType, $file];
             }
 
             if (preg_match('/^(?:(?:array|bool|float|int|string|iterable|([^ $]++)) )\$/', $key, $m)) {
@@ -263,8 +263,8 @@ private function getBindingValue(BoundArgument $binding): mixed
     {
         [$bindingValue, $bindingId] = $binding->getValues();
 
-        $this->usedBindings[$bindingId] = true;
-        unset($this->unusedBindings[$bindingId]);
+        $this->usedBindings[$bindingId ?? ''] = true;
+        unset($this->unusedBindings[$bindingId ?? '']);
 
         return $bindingValue;
     }

src/Symfony/Component/DependencyInjection/Compiler/ResolveHotPathPass.php

@@ -51,7 +51,7 @@ protected function processValue(mixed $value, bool $isRoot = false): mixed
                 return $value->clearTag('container.hot_path');
             }
 
-            $this->resolvedIds[$this->currentId] = true;
+            $this->resolvedIds[$this->currentId ?? ''] = true;
 
             if (!$value->hasTag('container.hot_path')) {
                 return $value;

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -207,7 +207,7 @@ public function registerExtension(ExtensionInterface $extension)
         $this->extensions[$extension->getAlias()] = $extension;
 
         if (false !== $extension->getNamespace()) {
-            $this->extensionsByNs[$extension->getNamespace()] = $extension;
+            $this->extensionsByNs[$extension->getNamespace() ?? ''] = $extension;
         }
     }
 

src/Symfony/Component/Form/Tests/Fixtures/FixedDataTransformer.php

@@ -25,6 +25,7 @@ public function __construct(array $mapping)
 
     public function transform($value): mixed
     {
+        $value ??= '';
         if (!\array_key_exists($value, $this->mapping)) {
             throw new TransformationFailedException(sprintf('No mapping for value "%s"', $value));
         }