HTML search: serialize search index as JSON

CHANGES.rst

@@ -20,6 +20,9 @@ Bugs fixed
 
 * #13060: HTML Search: use ``Map`` to store per-file term scores.
   Patch by James Addison
+* #13097: HTML Search: add a precautionary check for query term
+  presence in index properties before accessing them.
+  Patch by James Addison
 
 Testing
 -------

sphinx/themes/basic/static/searchtools.js

@@ -514,8 +514,8 @@ const Search = {
     searchTerms.forEach((word) => {
       const files = [];
       const arr = [
-        { files: terms[word], score: Scorer.term },
-        { files: titleTerms[word], score: Scorer.title },
+        { files: terms.hasOwnProperty(word) ? terms[word] : [], score: Scorer.term },
+        { files: titleTerms.hasOwnProperty(word) ? titleTerms[word] : [], score: Scorer.title },
       ];
       // add support for partial matches
       if (word.length > 2) {

tests/js/roots/ecmascript/index.rst

@@ -0,0 +1,8 @@
+ECMAScript
+----------
+
+This is a sample JavaScript (aka ``ECMAScript``) project used to generate a search engine index fixture.
+
+.. js:attribute:: Object.__proto__
+
+   Used to access the `prototype <https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Object_prototypes>`_ of an object instance.

tests/js/searchtools.spec.js

@@ -209,6 +209,38 @@ describe('Basic html theme search', function() {
 
   });
 
+  describe('can handle edge-case search queries', function() {
+
+    it('can search for the javascript prototype property', function() {
+      eval(loadFixture("ecmascript/searchindex.js"));
+
+      searchParameters = Search._parseQuery('__proto__');
+
+      hits = [
+        [
+          'index',
+          'Object.__proto__',
+          '#Object.__proto__',
+          'JavaScript attribute, in ECMAScript',
+          16,
+          'index.rst',
+          'object'
+        ]
+      ];
+      expect(Search._performSearch(...searchParameters)).toEqual(hits);
+    });
+
+    it('does not find the javascript prototype property in unrelated documents', function() {
+      eval(loadFixture("partial/searchindex.js"));
+
+      searchParameters = Search._parseQuery('__proto__');
+
+      hits = [];
+      expect(Search._performSearch(...searchParameters)).toEqual(hits);
+    });
+
+  });
+
 });
 
 describe("htmlToText", function() {