>From 76a471fd6ffed4993bf6b8114676715859ffd6c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <tex@2krueger.de>
Date: Tue, 20 Apr 2021 00:16:55 +0200
Subject: [PATCH 2/2] Right \mathstyle while reading \Udelimiter family

---
 source/texk/web2c/luatexdir/tex/texmath.c | 28 +++++++++++++++--------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/source/texk/web2c/luatexdir/tex/texmath.c b/source/texk/web2c/luatexdir/tex/texmath.c
index 461a51578..0c0e8a9cc 100644
--- a/source/texk/web2c/luatexdir/tex/texmath.c
+++ b/source/texk/web2c/luatexdir/tex/texmath.c
@@ -1580,6 +1580,7 @@ static void scan_delimiter(pointer p, int r)
 void math_radical(void)
 {
     halfword q;
+    int new_mstyle;
     int chr_code = cur_chr;
     halfword options = 0;
     tail_append(new_node(radical_noad, chr_code));
@@ -1600,28 +1601,35 @@ void math_radical(void)
         }
     }
     radicaloptions(tail) = options;
-    if (chr_code == 0)
+    if (chr_code == 0) {
         /*tex \.{\\radical} */
         scan_delimiter(left_delimiter(tail), tex_mathcode);
-    else if (chr_code == 1)
+        new_mstyle = cramped_style(m_style);
+    } else if (chr_code == 1) {
         /*tex \.{\\Uradical} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 2)
+        new_mstyle = cramped_style(m_style);
+    } else if (chr_code == 2) {
         /*tex \.{\\Uroot} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 3)
+        new_mstyle = cramped_style(m_style);
+    } else if (chr_code == 3) {
         /*tex \.{\\Uunderdelimiter} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 4)
+        new_mstyle = sub_style(m_style);
+    } else if (chr_code == 4) {
         /*tex \.{\\Uoverdelimiter} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 5)
+        new_mstyle = sup_style(m_style);
+    } else if (chr_code == 5) {
         /*tex \.{\\Udelimiterunder} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 6)
+        new_mstyle = m_style;
+    } else if (chr_code == 6) {
         /*tex \.{\\Udelimiterover} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
-    else if (chr_code == 7)
+        new_mstyle = cramped_style(m_style);
+    } else if (chr_code == 7)
         /*tex \.{\\Uhextensible} */
         scan_delimiter(left_delimiter(tail), umath_mathcode);
     else
@@ -1645,12 +1653,12 @@ void math_radical(void)
             vlink(degree(tail)) = null;
             q = new_node(math_char_node, 0);
             nucleus(tail) = q;
-            (void) scan_math(nucleus(tail), cramped_style(m_style));
+            (void) scan_math(nucleus(tail), new_mstyle);
         }
     } else {
         q = new_node(math_char_node, 0);
         nucleus(tail) = q;
-        (void) scan_math(nucleus(tail), cramped_style(m_style));
+        (void) scan_math(nucleus(tail), new_mstyle);
     }
 }
 
-- 
2.31.1