docs/sphinx: Fix TOC scroll hack for the home page

When on the documentation home page, there won't be any ".current"
element since no entry from the TOC was selected yet. That results in a
javascript error. Fix that by only trying to set the scrollTop if we
have matches for current entries.

Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240123162157.61819-2-gustavo.sousa@intel.com

diff --git a/Documentation/sphinx/templates/kernel-toc.html b/Documentation/sphinx/templates/kernel-toc.html
index b58efa99df527d3d870d9572e6ee7f18912fe99f..41f1efbe64bb2898f1770deb128630b316a68a08 100644 (file)
--- a/Documentation/sphinx/templates/kernel-toc.html
+++ b/Documentation/sphinx/templates/kernel-toc.html
@@ -12,5 +12,7 @@
 <script type="text/javascript"> <!--
   var sbar = document.getElementsByClassName("sphinxsidebar")[0];
   let currents = document.getElementsByClassName("current")
-  sbar.scrollTop = currents[currents.length - 1].offsetTop;
+  if (currents.length) {
+    sbar.scrollTop = currents[currents.length - 1].offsetTop;
+  }
   --> </script>