Fix identifers validation against null next node

The previous solution didn't account for
when a current node's literal had a valid
value but the next node was in fact null

app/assets/javascripts/vue_shared/components/rich_content_editor/services/renderers/render_identifier_text.js

@@ -33,7 +33,7 @@ const hasExitingPotential = literal => literal.includes(']: ');
 const hasAdjacentExit = node => {
   let currentNode = node;
 
-  while (currentNode.next && currentNode.literal !== null) {
+  while (currentNode && currentNode.literal !== null) {
     if (hasExitingPotential(currentNode.literal)) {
       return true;
     }

changelogs/unreleased/35775-inline-code-fix-for-custom-renderer-identifiers.yml

+---
+title: Fix unique case where static site editor's custom renderer for identifier syntax didn't robustly handle inline code
+merge_request: 35775
+author: Derek Knox
+type: fixed

spec/frontend/vue_shared/components/rich_content_editor/mock_data.js

@@ -19,9 +19,7 @@ const buildMockTextNodeWithAdjacentInlineCode = isForward => {
       type: 'code',
       [direction]: {
         literal: isForward ? literalClose : literalOpen,
-        [direction]: {
-          literal: null,
-        },
+        [direction]: null,
       },
     },
   };