allow search hits in body text that are in title of other doc #2891 (#2971)

* allow search hits in body text that are in title of other doc #2891

* shorten lines/add line breaks #2891

* remove out-commented LoC, simplify check #2891

sphinx/search/__init__.py

@@ -397,7 +397,8 @@ class IndexBuilder(object):
             # again, stemmer must not remove words from search index
             if not _filter(stemmed_word) and _filter(word):
                 stemmed_word = word
-            if stemmed_word not in self._title_mapping and _filter(stemmed_word):
+            already_indexed = docname in self._title_mapping.get(stemmed_word, [])
+            if _filter(stemmed_word) and not already_indexed:
                 self._mapping.setdefault(stemmed_word, set()).add(docname)
 
     def context_for_searchtool(self):

tests/roots/test-search/index.rst

@@ -11,4 +11,10 @@ Stemmer
 =======
 
 zfs
-findthisstemmedkey
+findthisstemmedkey
+
+textinheading
+
+.. toctree::
+
+   tocitem

tests/roots/test-search/tocitem.rst

@@ -0,0 +1,10 @@
+heading 1
+=========
+
+lorem ipsum
+
+
+textinheading
+=============
+
+lorem ipsum

tests/test_search.py

@@ -105,3 +105,13 @@ def test_stemmer_does_not_remove_short_words(app, status, warning):
 def test_stemmer(app, status, warning):
     searchindex = (app.outdir / 'searchindex.js').text()
     assert 'findthisstemmedkei' in searchindex
+
+
+@with_app(testroot='search')
+def test_term_in_heading_and_section(app, status, warning):
+    searchindex = (app.outdir / 'searchindex.js').text()
+    # if search term is in the title of one doc and in the text of another
+    # both documents should be a hit in the search index as a title,
+    # respectively text hit
+    assert 'textinhead:1' in searchindex
+    assert 'textinhead:0' in searchindex