Merge branch 'backport-epic-fullscreen' into 'master'

Backport epic fullscreen

See merge request gitlab-org/gitlab-ce!15437

(cherry picked from commit 04ceeac1f6c56f1c1f3faa9da6e8bc563b6c1393)

880c9a2c Backport fix epic fullscreen

2 files changed, 10 insertions, 3 deletions

diff --git a/app/assets/javascripts/dropzone_input.js b/app/assets/javascripts/dropzone_input.js
index b7747ee3f83..c84be42649a 100644
--- a/app/assets/javascripts/dropzone_input.js
+++ b/app/assets/javascripts/dropzone_input.js
@@ -36,7 +36,10 @@ export default function dropzoneInput(form) {
   $formDropzone.append(divHover);
   $formDropzone.find('.div-dropzone-hover').append(iconPaperclip);
 
-  if (!uploadsPath) return;
+  if (!uploadsPath) {
+    $formDropzone.addClass('js-invalid-dropzone');
+    return;
+  }
 
   const dropzone = $formDropzone.dropzone({
     url: uploadsPath,
diff --git a/app/assets/javascripts/zen_mode.js b/app/assets/javascripts/zen_mode.js
index cba7b9227cd..06a86f3b94a 100644
--- a/app/assets/javascripts/zen_mode.js
+++ b/app/assets/javascripts/zen_mode.js
@@ -71,7 +71,7 @@ export default class ZenMode {
     this.active_textarea = this.active_backdrop.find('textarea');
     // Prevent a user-resized textarea from persisting to fullscreen
     this.active_textarea.removeAttr('style');
-    return this.active_textarea.focus();
+    this.active_textarea.focus();
   }
 
   exit() {
@@ -81,7 +81,11 @@ export default class ZenMode {
       this.scrollTo(this.active_textarea);
       this.active_textarea = null;
       this.active_backdrop = null;
-      return Dropzone.forElement('.div-dropzone').enable();
+
+      const $dropzone = $('.div-dropzone');
+      if ($dropzone && !$dropzone.hasClass('js-invalid-dropzone')) {
+        Dropzone.forElement('.div-dropzone').enable();
+      }
     }
   }