Disabling drag and drop of attachments on non existing wiki pages

app/coffee/modules/common/components.coffee

@@ -656,7 +656,7 @@ EditableWysiwyg = (attachmentsService, attachmentsFullService) ->
     link = ($scope, $el, $attrs, $model) ->
 
         isInEditMode = ->
-            return $el.find('textarea').is(':visible')
+            return $el.find('textarea').is(':visible') and $model.$modelValue.id
 
 
         uploadFile = (file, type) ->

app/locales/taiga/locale-en.json

@@ -228,6 +228,7 @@
             "PREVIEW_BUTTON": "Preview",
             "EDIT_BUTTON": "Edit",
             "ATTACH_FILE_HELP": "Attach files by dragging & dropping on the textarea above.",
+            "ATTACH_FILE_HELP_SAVE_FIRST": "Save first before if you want to attach files by dragging & dropping on the textarea above.",
             "MARKDOWN_HELP": "Markdown syntax help"
         },
         "PERMISIONS_CATEGORIES": {

app/partials/common/components/wysiwyg.jade

@@ -1,6 +1,7 @@
 mixin wysihelp
     div.wysiwyg-help
-        span.drag-drop-help(translate="COMMON.WYSIWYG.ATTACH_FILE_HELP")
+        span.drag-drop-help(ng-if="wiki.id", translate="COMMON.WYSIWYG.ATTACH_FILE_HELP")
+        span.drag-drop-help(ng-if="!wiki.id", translate="COMMON.WYSIWYG.ATTACH_FILE_HELP_SAVE_FIRST")
         a.help-markdown(
             href="https://tree.taiga.io/support/misc/taiga-markdown-syntax/"
             target="_blank"