From 59621bde94a34a238be9d6130b3edd7850f8cb38 Mon Sep 17 00:00:00 2001
From: Carlos Scheidegger <carlos.scheidegger@rstudio.com>
Date: Thu, 5 Oct 2023 10:41:34 -0700
Subject: [PATCH] lua minor perf: return nil instead of unprocessed copy

---
 src/resources/filters/crossref/equations.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/resources/filters/crossref/equations.lua b/src/resources/filters/crossref/equations.lua
index 263eb8a9ca..c3ac0c1a1a 100644
--- a/src/resources/filters/crossref/equations.lua
+++ b/src/resources/filters/crossref/equations.lua
@@ -16,7 +16,7 @@ function process_equations(blockEl)
 
   -- do nothing if there is no math herein
   if inlines:find_if(isDisplayMath) == nil then
-    return blockEl
+    return nil
   end
 
   local mathInlines = nil