From f82f1a9a76b138168f7ad4f8f9015a570def285d Mon Sep 17 00:00:00 2001
From: The-Lum <86879521+The-Lum@users.noreply.github.com>
Date: Sun, 10 Mar 2024 17:09:12 +0000
Subject: [PATCH] fix: math two-dimensional matrices and add test

Report of https://github.com/The-Lum/ASCIIMathTeXImg/commit/6f3bb01d
That fixes #1706

Regards,
Th.
---
 src/net/sourceforge/plantuml/math/ASCIIMathTeXImg.java | 4 ++--
 test/net/sourceforge/plantuml/math/MathTest.java       | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/net/sourceforge/plantuml/math/ASCIIMathTeXImg.java b/src/net/sourceforge/plantuml/math/ASCIIMathTeXImg.java
index 7a23f266783..d4d32969b61 100644
--- a/src/net/sourceforge/plantuml/math/ASCIIMathTeXImg.java
+++ b/src/net/sourceforge/plantuml/math/ASCIIMathTeXImg.java
@@ -905,8 +905,8 @@ private String[] AMTparseExpr(String str, boolean rightbracket) {
 										subarr = new ArrayList<String>(Arrays.asList(
 												newFrag.substring(pos.get(i) + 8, subpos.get(pos.get(i)).get(1))));
 										for (int j = 2; j < subpos.get(pos.get(i)).size(); j++) {
-											subarr.add(newFrag.substring(subpos.get(i).get(j - 1) + 1,
-													subpos.get(i).get(j)));
+											subarr.add(newFrag.substring(subpos.get(pos.get(i)).get(j - 1) + 1,
+													subpos.get(pos.get(i)).get(j)));
 										}
 										subarr.add(newFrag.substring(
 												subpos.get(pos.get(i)).get(subpos.get(pos.get(i)).size() - 1) + 1,
diff --git a/test/net/sourceforge/plantuml/math/MathTest.java b/test/net/sourceforge/plantuml/math/MathTest.java
index d649d9c77f4..391ff41d612 100644
--- a/test/net/sourceforge/plantuml/math/MathTest.java
+++ b/test/net/sourceforge/plantuml/math/MathTest.java
@@ -17,6 +17,9 @@ class MathTest {
 			" '[[a,b],[c,d]]',              {\\left[\\begin{matrix}{a}&{b}\\\\{c}&{d}\\end{matrix}\\right]} ",
 			" color(red)(x),                {\\textcolor{red}{{x}}} ",
 			" color(red)(t)=color(blue)(x), {\\textcolor{red}{{t}}}={\\textcolor{blue}{{x}}} ",
+			" f,                            {f} ",
+			" f_g,                          {{f}_{{g}}} ",
+			" '[[1,2,3],[4,5,6]]',          {\\left[\\begin{matrix}{1}&{2}&{3}\\\\{4}&{5}&{6}\\end{matrix}\\right]} ",
 	})
 	public void testMath(String input, String expected) {
 		final String res = new ASCIIMathTeXImg().getTeX(input);