Merge that good fresh upstream shit

app/javascript/mastodon/actions/compose.js

@@ -28,6 +28,7 @@ export const COMPOSE_SPOILERNESS_CHANGE = 'COMPOSE_SPOILERNESS_CHANGE';
 export const COMPOSE_SPOILER_TEXT_CHANGE = 'COMPOSE_SPOILER_TEXT_CHANGE';
 export const COMPOSE_VISIBILITY_CHANGE  = 'COMPOSE_VISIBILITY_CHANGE';
 export const COMPOSE_LISTABILITY_CHANGE = 'COMPOSE_LISTABILITY_CHANGE';
+export const COMPOSE_COMPOSING_CHANGE = 'COMPOSE_COMPOSING_CHANGE';
 
 export const COMPOSE_EMOJI_INSERT = 'COMPOSE_EMOJI_INSERT';
 
@@ -288,3 +289,10 @@ export function insertEmojiCompose(position, emoji) {
     emoji,
   };
 };
+
+export function changeComposing(value) {
+  return {
+    type: COMPOSE_COMPOSING_CHANGE,
+    value,
+  };
+}