disable scroll past end for diff editor

hide diff overview in diff editor

app/assets/stylesheets/pages/repo.scss

@@ -706,3 +706,7 @@
 .ide-commit-new-branch {
   margin-left: 25px;
 }
+
+.ide-editor-diff {
+  margin-right: -30px;
+}

ee/app/assets/javascripts/ide/components/repo_editor.vue

@@ -20,6 +20,9 @@ export default {
     shouldHideEditor() {
       return this.activeFile && this.activeFile.binary && !this.activeFile.raw;
     },
+    ideClassName() {
+      return `ide-editor-${this.viewer}`;
+    },
   },
   watch: {
     activeFile(oldVal, newVal) {
@@ -138,6 +141,7 @@ export default {
   <div
     id="ide"
     class="blob-viewer-container blob-editor-container"
+    :class="ideClassName"
   >
     <div
       v-if="shouldHideEditor"

ee/app/assets/javascripts/ide/lib/editor.js

@@ -70,6 +70,7 @@ export default class Editor {
       this.disposable.add(
         this.instance = this.monaco.editor.createDiffEditor(domElement, {
           readOnly: true,
+          scrollBeyondLastLine: false,
         }),
       );
 

spec/javascripts/ide/lib/editor_spec.js

@@ -66,6 +66,7 @@ describe('Multi-file editor library', () => {
 
       expect(instance.monaco.editor.createDiffEditor).toHaveBeenCalledWith(holder, {
         readOnly: true,
+        scrollBeyondLastLine: false,
       });
     });
   });