[LyX/master] MathML: output substacks as grids.

[Thibaut Cuvelier]

commit 5893ea866e99c406d6422257dd1a8ab5c7bc7f30
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Fri Dec 9 01:48:14 2022 +0100

    MathML: output substacks as grids.
    
    Based on a commit from lynx <lorenzobertini97 at gmail.com>
    
    Part of bug #12590.
---
 src/mathed/InsetMathSubstack.cpp |   13 ++-----------
 1 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/mathed/InsetMathSubstack.cpp b/src/mathed/InsetMathSubstack.cpp
index 5db39c2..649f947 100644
--- a/src/mathed/InsetMathSubstack.cpp
+++ b/src/mathed/InsetMathSubstack.cpp
@@ -156,17 +156,8 @@ void InsetMathSubstack::maple(MapleStream & os) const
 
 void InsetMathSubstack::mathmlize(MathMLStream & ms) const
 {
-	int movers = 0;
-	row_type const numrows = nrows();
-	for (row_type row = 0; row < nrows(); ++row) {
-		if (row < numrows - 1) {
-			movers ++;
-			ms << MTag("munder");
-		}
-		ms << MTag("mrow") << cell(index(row, 0)) << ETag("mrow");
-	}
-	for (int i = 1; i <= movers; ++i)
-		ms << ETag("munder");
+	// Output the substack as a standard grid.
+	InsetMathGrid::mathmlize(ms);
 }