cleanup precondition checking when creating new files / folders

- use i18n
- use trim when checking for empty file / folder name
- use more verbose error descriptions

apps/files/ajax/newfile.php

@@ -20,15 +20,6 @@ if($source) {
 	OC_JSON::callCheck();
 }
 
-if($filename == '') {
-	OCP\JSON::error(array("data" => array( "message" => "Empty Filename" )));
-	exit();
-}
-if(strpos($filename, '/')!==false) {
-	OCP\JSON::error(array("data" => array( "message" => "Invalid Filename" )));
-	exit();
-}
-
 function progress($notification_code, $severity, $message, $message_code, $bytes_transferred, $bytes_max) {
 	static $filesize = 0;
 	static $lastsize = 0;
@@ -54,10 +45,28 @@ function progress($notification_code, $severity, $message, $message_code, $bytes
 	}
 }
 
-$target = $dir.'/'.$filename;
-
 $l10n = \OC_L10n::get('files');
 
+$result = array(
+	'success' 	=> false,
+	'data'		=> NULL
+	);
+
+if(trim($filename) === '') {
+	$result['data'] = array('message' => $l10n->t('Filename cannot not be empty.'));
+	OCP\JSON::error($result);
+	exit();
+}
+
+if(strpos($filename, '/') !== false) {
+	$result['data'] = array('message' => $l10n->t('Filename must not contain /. Please choose a different name.'));
+	OCP\JSON::error($result);
+	exit();
+}
+
+//TODO why is stripslashes used on foldername in newfolder.php but not here?
+$target = $dir.'/'.$filename;
+
 if (\OC\Files\Filesystem::file_exists($target)) {
 		$result = array(
 			'success' 	=> false,

apps/files/ajax/newfolder.php

@@ -10,25 +10,47 @@ OCP\JSON::callCheck();
 $dir = isset( $_POST['dir'] ) ? stripslashes($_POST['dir']) : '';
 $foldername = isset( $_POST['foldername'] ) ? stripslashes($_POST['foldername']) : '';
 
-if(trim($foldername) == '') {
-	OCP\JSON::error(array("data" => array( "message" => "Empty Foldername" )));
+$l10n = \OC_L10n::get('files');
+
+$result = array(
+	'success' 	=> false,
+	'data'		=> NULL
+	);
+
+if(trim($foldername) === '') {
+	$result['data'] = array('message' => $l10n->t('Foldername cannot not be empty.'));
+	OCP\JSON::error($result);
+	exit();
+}
+
+if(strpos($foldername, '/') !== false) {
+	$result['data'] = array('message' => $l10n->t('Foldername must not contain /. Please choose a different name.'));
+	OCP\JSON::error($result);
 	exit();
 }
-if(strpos($foldername, '/')!==false) {
-	OCP\JSON::error(array("data" => array( "message" => "Invalid Foldername" )));
+
+//TODO why is stripslashes used on foldername here but not in newfile.php?
+$target = $dir . '/' . stripslashes($foldername);
+		
+if (\OC\Files\Filesystem::file_exists($target)) {
+	$result['data'] = array('message' => $l10n->t(
+			'The name %s is already used in the folder %s. Please choose a different name.',
+			array($foldername, $dir))
+		);
+	OCP\JSON::error($result);
 	exit();
 }
 
-if(\OC\Files\Filesystem::mkdir($dir . '/' . stripslashes($foldername))) {
-	if ( $dir != '/') {
+if(\OC\Files\Filesystem::mkdir($target)) {
+	if ( $dir !== '/') {
 		$path = $dir.'/'.$foldername;
 	} else {
 		$path = '/'.$foldername;
 	}
 	$meta = \OC\Files\Filesystem::getFileInfo($path);
 	$id = $meta['fileid'];
-	OCP\JSON::success(array("data" => array('id'=>$id)));
+	OCP\JSON::success(array('data' => array('id' => $id)));
 	exit();
 }
 
-OCP\JSON::error(array("data" => array( "message" => "Error when creating the folder" )));
+OCP\JSON::error(array('data' => array( 'message' => 'Error when creating the folder' )));