adapt free space calculation to the way it is done for the trash bin

apps/files_versions/lib/versions.php

@@ -378,12 +378,14 @@ class Storage {
 			$versions_fileview = new \OC\Files\View('/'.$uid.'/files_versions');
 
 			// get available disk space for user
+			$softQuota = true;
 			$quota = \OC_Preferences::getValue($uid, 'files', 'quota');
 			if ( $quota === null || $quota === 'default') {
 				$quota = \OC_Appconfig::getValue('files', 'default_quota');
 			}
 			if ( $quota === null || $quota === 'none' ) {
-				$quota = \OC\Files\Filesystem::free_space('/') / count(\OCP\User::getUsers());
+				$quota = \OC\Files\Filesystem::free_space('/');
+				$softQuota = false;
 			} else {
 				$quota = \OCP\Util::computerFileSize($quota);
 			}
@@ -397,6 +399,8 @@ class Storage {
 			}
 
 			// calculate available space for version history
+			// subtract size of files and current versions size from quota
+			if ($softQuota) {
 				$files_view = new \OC\Files\View('/'.$uid.'/files');
 				$rootInfo = $files_view->getFileInfo('/');
 				$free = $quota-$rootInfo['size']; // remaining free space for user
@@ -405,6 +409,10 @@ class Storage {
 				} else {
 					$availableSpace = $free-$versionsSize;
 				}
+			} else {
+				$availableSpace = $quota;
+			}
+
 
 			// after every 1000s run reduce the number of all versions not only for the current file
 			$random = rand(0, 1000);