Fix for issue #462

Modified uploadCompose action to send media ids of attached
media when sending a request. Modified create method in MediaController
to check if when posting a video, there are no other media attached
to the status by looking at the media ids sent from the uploadCompose
action.

app/assets/javascripts/components/actions/compose.jsx

@@ -119,7 +119,10 @@ export function uploadCompose(files) {
 
     let data = new FormData();
     data.append('file', files[0]);
-
+    data.append('media_ids', getState().getIn(
+      ['compose', 'media_attachments']
+    ).map(item => item.get('id')));
+    
     api(getState).post('/api/v1/media', data, {
       onUploadProgress: function (e) {
         dispatch(uploadComposeProgress(e.loaded, e.total));

app/controllers/api/v1/media_controller.rb

@@ -11,6 +11,10 @@ class Api::V1::MediaController < ApiController
 
   def create
     @media = MediaAttachment.create!(account: current_user.account, file: params[:file])
+    if @media.video? and params[:media_ids] != "List []"
+      @media.destroy
+      render json: {error: 'Cannot attach a video to a toot that already contains images'}, status: 422
+    end
   rescue Paperclip::Errors::NotIdentifiedByImageMagickError
     render json: { error: 'File type of uploaded media could not be verified' }, status: 422
   rescue Paperclip::Error