From 4e737cf37f2ac658732ed6db15bbb844e2da2bed Mon Sep 17 00:00:00 2001
From: Davo Smith <davo.smith@synergy-learning.com>
Date: Wed, 6 Dec 2017 09:33:44 +0000
Subject: [PATCH] MDL-60427 dndupload: detect attempts to upload folders

---
 course/dndupload.js     | 29 +++++++++++++++++++++++------
 course/dnduploadlib.php |  1 +
 lang/en/moodle.php      |  1 +
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/course/dndupload.js b/course/dndupload.js
index 7c60ee00a1b..f15f6a4a9c5 100644
--- a/course/dndupload.js
+++ b/course/dndupload.js
@@ -410,12 +410,12 @@ M.course_dndupload = {
      * @return false to prevent the event from continuing to be processed
      */
     drop: function(e) {
+        this.hide_preview_element();
+
         if (!(type = this.check_drag(e))) {
             return false;
         }
 
-        this.hide_preview_element();
-
         // Work out the number of the section we are on (from its id)
         var section = this.get_section(e.currentTarget);
         var sectionnumber = this.get_section_number(section);
@@ -792,16 +792,33 @@ M.course_dndupload = {
 
         // Prepare the data to send
         var formData = new FormData();
-        formData.append('repo_upload_file', file);
+        try {
+            formData.append('repo_upload_file', file);
+        } catch (e) {
+            // Edge throws an error at this point if we try to upload a folder.
+            resel.parent.removeChild(resel.li);
+            new M.core.alert({message: M.util.get_string('filereaderror', 'moodle', file.name)});
+            return;
+        }
         formData.append('sesskey', M.cfg.sesskey);
         formData.append('course', this.courseid);
         formData.append('section', sectionnumber);
         formData.append('module', module);
         formData.append('type', 'Files');
 
-        // Send the AJAX call
-        xhr.open("POST", this.url, true);
-        xhr.send(formData);
+        // Try reading the file to check it is not a folder, before sending it to the server.
+        var reader = new FileReader();
+        reader.onload = function() {
+            // File was read OK - send it to the server.
+            xhr.open("POST", self.url, true);
+            xhr.send(formData);
+        };
+        reader.onerror = function() {
+            // Unable to read the file (it is probably a folder) - display an error message.
+            resel.parent.removeChild(resel.li);
+            new M.core.alert({message: M.util.get_string('filereaderror', 'moodle', file.name)});
+        };
+        reader.readAsText(file.slice(0, 5)); // Try reading the first few bytes of the file.
     },
 
     /**
diff --git a/course/dnduploadlib.php b/course/dnduploadlib.php
index 73ecfc89d38..1e1210570d2 100644
--- a/course/dnduploadlib.php
+++ b/course/dnduploadlib.php
@@ -64,6 +64,7 @@ function dndupload_add_to_course($course, $modnames) {
             array('namedfiletoolarge', 'moodle'),
             array('actionchoice', 'moodle'),
             array('servererror', 'moodle'),
+            array('filereaderror', 'moodle'),
             array('upload', 'moodle'),
             array('cancel', 'moodle')
         ),
diff --git a/lang/en/moodle.php b/lang/en/moodle.php
index f1eb2524416..99db34be552 100644
--- a/lang/en/moodle.php
+++ b/lang/en/moodle.php
@@ -799,6 +799,7 @@ $string['feedback'] = 'Feedback';
 $string['file'] = 'File';
 $string['fileexists'] = 'There is already a file called {$a}';
 $string['filemissing'] = '{$a} is missing';
+$string['filereaderror'] = 'Unable to read the file \'{$a}\' - please check this really is a file and not a folder';
 $string['files'] = 'Files';
 $string['filesanduploads'] = 'Files and uploads';
 $string['filesfolders'] = 'Files/folders';