Merge pull request #6835 from rxu/ticket/17529

[ticket/17529] Fix installer config.php availability checks

phpBB/phpbb/install/module/requirements/task/check_filesystem.php

@@ -145,7 +145,12 @@ class check_filesystem extends \phpbb\install\task_base
 		// Try to create file if it does not exists
 		if (!file_exists($path))
 		{
-			$fp = @fopen($path, 'w');
+			if (!is_resource($fp = @fopen($path, 'w')))
+			{
+				$exists = $writable = false;
+			}
+			else
+			{
 				@fclose($fp);
 				try
 				{
@@ -155,21 +160,14 @@ class check_filesystem extends \phpbb\install\task_base
 					$exists = true;
 				}
 				catch (\phpbb\filesystem\exception\filesystem_exception $e)
-			{
-				// Do nothing
-			}
-		}
-
-		if (file_exists($path))
-		{
-			if (!$this->filesystem->is_writable($path))
 				{
 					$writable = false;
 				}
 			}
-		else
+		}
+		else if (!$this->filesystem->is_writable($path))
 		{
-			$exists = $writable = false;
+			$writable = false;
 		}
 
 		$this->set_test_passed(($exists && $writable) || $failable);