[LyX/master] MathML: remove extraneous <mrow> in fractions

[Thibaut Cuvelier]

commit 0c227d3dfa48500d4889f8a39f627a7db8ad5666
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Fri Jan 20 02:30:35 2023 +0100

    MathML: remove extraneous <mrow> in fractions
    
    Contributed by lynx: https://www.lyx.org/trac/ticket/12629
---
 src/mathed/InsetMathFrac.cpp |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mathed/InsetMathFrac.cpp b/src/mathed/InsetMathFrac.cpp
index 2431f68..4ce758e 100644
--- a/src/mathed/InsetMathFrac.cpp
+++ b/src/mathed/InsetMathFrac.cpp
@@ -506,8 +506,8 @@ void InsetMathFrac::mathmlize(MathMLStream & ms) const
 	switch (kind_) {
 	case ATOP:
 		ms << MTag("mfrac", "linethickness='0'")
-		   << MTag("mrow") << cell(0) << ETag("mrow")
-		   << MTag("mrow") << cell(1) << ETag("mrow")
+		   << cell(0)
+		   << cell(1)
 		   << ETag("mfrac");
 		break;