remove issue autocomplete for epic issues

app/assets/javascripts/issuable/related_issues/components/add_issuable_form.vue

@@ -43,12 +43,15 @@ export default {
 
   computed: {
     inputPlaceholder() {
-      return 'Paste issue link or <#issue id>';
+      return `Paste issue link${this.allowAutoComplete ? ' or <#issue id>' : ''}`;
     },
     isSubmitButtonDisabled() {
       return (this.inputValue.length === 0 && this.pendingReferences.length === 0)
         || this.isSubmitting;
     },
+    allowAutoComplete() {
+      return Object.keys(this.autoCompleteSources).length > 0;
+    },
   },
 
   methods: {
@@ -86,12 +89,14 @@ export default {
   mounted() {
     const $input = $(this.$refs.input);
 
-    this.gfmAutoComplete = new GfmAutoComplete(this.autoCompleteSources);
-    this.gfmAutoComplete.setup($input, {
-      issues: true,
-    });
-    $input.on('shown-issues.atwho', this.onAutoCompleteToggled.bind(this, true));
-    $input.on('hidden-issues.atwho', this.onAutoCompleteToggled.bind(this, false));
+    if (this.allowAutoComplete) {
+      this.gfmAutoComplete = new GfmAutoComplete(this.autoCompleteSources);
+      this.gfmAutoComplete.setup($input, {
+        issues: true,
+      });
+      $input.on('shown-issues.atwho', this.onAutoCompleteToggled.bind(this, true));
+      $input.on('hidden-issues.atwho', this.onAutoCompleteToggled.bind(this, false));
+    }
 
     this.$refs.input.focus();
   },

app/assets/javascripts/issuable/related_issues/components/related_issues_root.vue

@@ -55,6 +55,11 @@ export default {
       required: false,
       default: 'Related issues',
     },
+    allowAutoComplete: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
   },
 
   data() {
@@ -75,6 +80,7 @@ export default {
 
   computed: {
     autoCompleteSources() {
+      if (!this.allowAutoComplete) return {};
       return gl.GfmAutoComplete && gl.GfmAutoComplete.dataSources;
     },
   },

ee/app/assets/javascripts/epics/epic_show/components/epic_show_app.vue

@@ -103,8 +103,8 @@
       <related-issues-root
         :endpoint="issuesEndpoint"
         :can-add-related-issues="true"
+        :allow-auto-complete="false"
         title="Issues"
-        help-path="/"
       />
     </div>
   </div>