MDL-36900 files: D&D upload uses new file name increment function

lib/form/dndupload.js

@@ -778,41 +778,17 @@ M.form_dndupload.init = function(Y, options) {
         },
 
         /**
-         * Adds _NUMBER to the end of the filename and increments this number until
-         * a unique name is found
+         * Gets a unique file name
+         *
          * @param string filename
          * @return string the unique filename generated
          */
         generate_unique_name: function(filename) {
-            // Split the filename into the basename + extension.
-            var extension;
-            var basename;
-            var dotpos = filename.lastIndexOf('.');
-            if (dotpos == -1) {
-                basename = filename;
-                extension = '';
-            } else {
-                basename = filename.substr(0, dotpos);
-                extension = filename.substr(dotpos, filename.length);
-            }
-
-            // Look to see if the name already has (NN) at the end of it.
-            var number = 0;
-            var hasnumber = basename.match(/^(.*) \((\d+)\)$/);
-            if (hasnumber !== null) {
-                // Note the current number & remove it from the basename.
-                number = parseInt(hasnumber[2], 10);
-                basename = hasnumber[1];
-            }
-
             // Loop through increating numbers until a unique name is found.
-            var newname;
-            do {
-                number++;
-                newname = basename + ' (' + number + ')' + extension;
-            } while (this.has_name_clash(newname));
-
-            return newname;
+            while (this.has_name_clash(filename)) {
+                filename = increment_filename(filename);
+            }
+            return filename;
         },
 
         /**