Do not run window.history.replaceState unconditionally

Currently every Sphinx documentation page *always* drops `#:~:text=...` Text Fragments unconditionally due to `window.history.replaceState`.

The solution is to only call `window.history.replaceState` when a `?highlight=...` param is part of the URL.

Author: haampie

CHANGES.rst

@@ -140,6 +140,8 @@ Bugs fixed
 * #14059: LaTeX: Footnotes cause pdflatex error with French language
   (since late June 2025 upstream change to LaTeX ``babel-french``).
   Patch by Jean-François B.
+* #13916: HTML Search: do not clear text fragments from the URL on page load.
+  Patch by Harmen Stoppels.
 
 
 Testing

sphinx/themes/basic/static/sphinx_highlight.js

@@ -80,8 +80,10 @@ const SphinxHighlight = {
       || url.searchParams.get("highlight")
       || "";
     localStorage.removeItem("sphinx_highlight_terms");
-    url.searchParams.delete("highlight");
-    window.history.replaceState({}, "", url);
+    if (url.searchParams.has("highlight")) {
+      url.searchParams.delete("highlight");
+      window.history.replaceState({}, "", url);
+    }
 
     // get individual terms from highlight string
     const terms = highlight