Fixes to launch Magento with PHP 8.1

Author: Karyna Tsymbal

app/code/Magento/Backend/App/DefaultPath.php

@@ -24,7 +24,8 @@ class DefaultPath implements \Magento\Framework\App\DefaultPathInterface
      */
     public function __construct(\Magento\Backend\App\ConfigInterface $config)
     {
-        $pathParts = explode('/', $config->getValue('web/default/admin'));
+        $path = $config->getValue('web/default/admin');
+        $pathParts = $path ? explode('/', $path) : [''];
 
         $this->_parts = [
             'area' => isset($pathParts[0]) ? $pathParts[0] : '',

app/code/Magento/Backend/view/adminhtml/templates/widget/tabshoriz.phtml

@@ -19,7 +19,7 @@ use Magento\Framework\View\Helper\SecureHtmlRenderer;
     <?php foreach ($tabs as $_tab): ?>
         <?php $tabId = $block->getTabId($_tab) ?>
         <?php $_tabClass = 'tab-item-link ' . $block->getTabClass($_tab) . ' ' .
-            (preg_match('/\s?ajax\s?/', $_tab->getClass()) ? 'notloaded' : '') ?>
+            (preg_match('/\s?ajax\s?/', $_tab->getClass() ?? '') ? 'notloaded' : '') ?>
         <?php $_tabType = (!preg_match('/\s?ajax\s?/', $_tabClass) && $block->getTabUrl($_tab) != '#') ? 'link' : '' ?>
         <?php $_tabHref = $block->getTabUrl($_tab) == '#' ?
             '#' . $tabId . '_content' :

app/code/Magento/Eav/Model/Entity/Type.php

@@ -303,7 +303,7 @@ public function getValueTablePrefix()
      */
     public function getEntityTablePrefix()
     {
-        $tablePrefix = trim($this->_data['value_table_prefix']);
+        $tablePrefix = isset($this->_data['value_table_prefix']) ? trim($this->_data['value_table_prefix']) : '';
 
         if (empty($tablePrefix)) {
             $tablePrefix = $this->getEntityTable();

lib/internal/Magento/Framework/DB/Adapter/Pdo/Mysql.php

@@ -1760,10 +1760,10 @@ public function getColumnCreateByDescribe($columnData)
         if ($columnData['DEFAULT'] !== null && $type != Table::TYPE_TEXT) {
             $options['default'] = $this->quote($columnData['DEFAULT']);
         }
-        if (strlen($columnData['SCALE']) > 0) {
+        if (isset($columnData['SCALE']) && strlen($columnData['SCALE']) > 0) {
             $options['scale'] = $columnData['SCALE'];
         }
-        if (strlen($columnData['PRECISION']) > 0) {
+        if (isset($columnData['PRECISION']) && strlen($columnData['PRECISION']) > 0) {
             $options['precision'] = $columnData['PRECISION'];
         }
 

lib/internal/Magento/Framework/DB/Ddl/Table.php

@@ -381,7 +381,7 @@ public function addColumn($name, $type, $size = null, $options = [], $comment =
                         $precision = $size[0];
                         $scale = $size[1];
                     }
-                } elseif (preg_match('#^(\d+),(\d+)$#', $size, $match)) {
+                } elseif ($size && preg_match('#^(\d+),(\d+)$#', $size, $match)) {
                     $precision = $match[1];
                     $scale = $match[2];
                 }

lib/internal/Magento/Framework/Filesystem/Driver/File.php

@@ -962,7 +962,7 @@ public function getAbsolutePath($basePath, $path, $scheme = null)
         // check if the path given is already an absolute path containing the
         // basepath. so if the basepath starts at position 0 in the path, we
         // must not concatinate them again because path is already absolute.
-        if (0 === strpos($path, $basePath)) {
+        if ($path && strpos($path, $basePath) === 0) {
             return $this->getScheme($scheme) . $path;
         }
 
@@ -997,7 +997,7 @@ public function getRelativePath($basePath, $path = null)
      */
     protected function fixSeparator($path)
     {
-        return str_replace('\\', '/', $path);
+        return $path ? str_replace('\\', '/', $path) : '';
     }
 
     /**
@@ -1074,8 +1074,8 @@ public function getRealPathSafety($path)
             $path
         );
 
-        if (strpos($path, DIRECTORY_SEPARATOR . '.') === false) {
-            return rtrim($path, DIRECTORY_SEPARATOR);
+        if (!$path || strpos($path, DIRECTORY_SEPARATOR . '.') === false) {
+            return $path ? rtrim($path, DIRECTORY_SEPARATOR) : '';
         }
 
         $pathParts = explode(DIRECTORY_SEPARATOR, $path);

lib/internal/Magento/Framework/Stdlib/DateTime.php

@@ -70,7 +70,7 @@ public function formatDate($date, $includeTime = true)
      */
     public function isEmptyDate($date)
     {
-        return preg_replace('#[ 0:-]#', '', $date) === '';
+        return !$date || preg_replace('#[ 0:-]#', '', $date) === '';
     }
 
     /**

lib/internal/Magento/Framework/Stdlib/DateTime/Timezone.php

@@ -264,6 +264,8 @@ public function scopeTimeStamp($scope = null)
      */
     public function isScopeDateInInterval($scope, $dateFrom = null, $dateTo = null)
     {
+        $dateFrom = $dateFrom ?: '';
+        $dateTo = $dateTo ?: '';
         if (!$scope instanceof ScopeInterface) {
             $scope = $this->_scopeResolver->getScope($scope);
         }

lib/internal/Magento/Framework/Url.php

@@ -504,7 +504,7 @@ protected function _setRoutePath($data)
         }
 
         $this->unsetData('route_path');
-        $routePieces = explode('/', $data);
+        $routePieces = $data ? explode('/', $data) : [''];
 
         $route = array_shift($routePieces);
         if ('*' === $route) {