BUG#AC-901: Cant install Magento in interactive mode

Author: glo80326

setup/src/Magento/Setup/Console/Command/InstallCommand.php

@@ -363,7 +363,7 @@ private function interactiveQuestions(InputInterface $input, OutputInterface $ou
     /**
      * Runs interactive questions
      *
-     * It will ask users for interactive questionst regarding setup configuration.
+     * It will ask users for interactive questions regarding setup configuration.
      *
      * @param InputInterface $input
      * @param OutputInterface $output
@@ -410,14 +410,11 @@ private function askQuestion(
         $question->setValidator(function ($answer) use ($option, $validateInline) {
 
             if ($option instanceof \Magento\Framework\Setup\Option\SelectConfigOption) {
-                $answer = $option->getSelectOptions()[$answer];
+                //If user doesn't provide an input & default value for question is not set, take first option as input.
+                $answer = $option->getSelectOptions()[$answer] ?? current($option->getSelectOptions());
             }
 
-            if ($answer == null) {
-                $answer = '';
-            } else {
-                $answer = is_string($answer) ? trim($answer) : $answer;
-            }
+            $answer = $answer === null ? '' : (is_string($answer) ? trim($answer) : $answer);
 
             if ($validateInline) {
                 $option->validate($answer);

setup/src/Magento/Setup/Model/ConfigModel.php

@@ -11,6 +11,7 @@
 use Magento\Framework\App\DeploymentConfig\Writer;
 use Magento\Framework\Setup\Option\AbstractConfigOption;
 use Magento\Framework\Setup\FilePermissions;
+use \Magento\Setup\Exception as SetupException;
 
 class ConfigModel
 {
@@ -68,9 +69,11 @@ public function getAvailableOptions()
         $optionLists = $this->collector->collectOptionsLists();
 
         foreach ($optionLists as $optionList) {
-            $optionCollection = array_merge($optionCollection, $optionList->getOptions());
+            $optionCollection[] = $optionList->getOptions();
         }
 
+        $optionCollection = array_merge([], ...$optionCollection);
+
         foreach ($optionCollection as $option) {
             $currentValue = $this->deploymentConfig->get($option->getConfigPath());
             if ($currentValue !== null) {
@@ -100,7 +103,7 @@ public function process($inputOptions)
             foreach ($configData as $config) {
                 $fileConfigStorage = [];
                 if (!$config instanceof ConfigData) {
-                    throw new \Exception(
+                    throw new SetupException(
                         'In module : '
                         . $moduleName
                         . 'ConfigOption::createConfig should return an array of ConfigData instances'
@@ -149,10 +152,10 @@ public function validate(array $inputOptions)
         $options = $this->collector->collectOptionsLists();
 
         foreach ($options as $option) {
-            $errors = array_merge($errors, $option->validate($inputOptions, $this->deploymentConfig));
+            $errors[] = $option->validate($inputOptions, $this->deploymentConfig);
         }
 
-        return $errors;
+        return array_merge([], ...$errors);
     }
 
     /**
@@ -166,7 +169,7 @@ private function checkInstallationFilePermissions()
         $results = $this->filePermissions->getMissingWritablePathsForInstallation();
         if ($results) {
             $errorMsg = "Missing write permissions to the following paths:" . PHP_EOL . implode(PHP_EOL, $results);
-            throw new \Exception($errorMsg);
+            throw new SetupException($errorMsg);
         }
     }
 }

setup/src/Magento/Setup/Model/ConfigOptionsList.php

@@ -252,7 +252,8 @@ public function validate(array $options, DeploymentConfig $deploymentConfig)
             $errors[] = $this->validateDbPrefix($options[ConfigOptionsListConstants::INPUT_KEY_DB_PREFIX]);
         }
 
-        if ($options[ConfigOptionsListConstants::INPUT_KEY_SKIP_DB_VALIDATION] ?? false) {
+        if (isset($options[ConfigOptionsListConstants::INPUT_KEY_SKIP_DB_VALIDATION]) &&
+            !$options[ConfigOptionsListConstants::INPUT_KEY_SKIP_DB_VALIDATION]) {
             $errors[] = $this->validateDbSettings($options, $deploymentConfig);
         }