Add plain property to active file if not set already

app/assets/javascripts/repo/components/repo_editor.vue

@@ -11,7 +11,7 @@ const RepoEditor = {
     Service.getRaw(this.activeFile.raw_path)
     .then((rawResponse) => {
       Store.blobRaw = rawResponse.data;
-      this.openedFiles[0].plain = rawResponse.data;
+      Helper.findOpenedFileFromActive().plain = rawResponse.data;
 
       const monacoInstance = this.monaco.editor.create(this.$el, {
         model: null,

app/assets/javascripts/repo/helpers/repo_helper.js

@@ -289,6 +289,10 @@ const RepoHelper = {
     }
   },
 
+  findOpenedFileFromActive() {
+    return Store.openedFiles.find(openedFile => Store.activeFile.url === openedFile.url);
+  },
+
   loadingError() {
     Flash('Unable to load the file at this time.');
   },

app/assets/javascripts/repo/stores/repo_store.js

 /* global Flash */
 import RepoHelper from '../helpers/repo_helper';
+import RepoService from '../services/repo_service';
 
 const RepoStore = {
   ideEl: {},
@@ -95,8 +96,14 @@ const RepoStore = {
     if (file.binary) {
       RepoStore.blobRaw = file.base64;
       RepoStore.binaryMimeType = file.mime_type;
-    } else {
+    } else if (file.newContent || file.plain) {
       RepoStore.blobRaw = file.newContent || file.plain;
+    } else {
+      RepoService.getRaw(file.raw_path)
+        .then((rawResponse) => {
+          RepoStore.blobRaw = rawResponse.data;
+          RepoHelper.findOpenedFileFromActive().plain = rawResponse.data;
+        }).catch(RepoHelper.loadingError);
     }
 
     if (!file.loading) RepoHelper.toURL(file.url, file.name);