From f0543f8ce8f6d3da44e825160502cd6b79b93090 Mon Sep 17 00:00:00 2001
From: Andrew <andrew.telnov@gmail.com>
Date: Mon, 9 Dec 2024 11:36:25 +0000
Subject: [PATCH] The row is added incorrectly if errors shows on the bottom
 and detail open is open in the last row fix #9147 (#9148)

---
 .../src/question_matrixdropdownrendered.ts    |  7 +-
 .../tests/question_matrixdynamictests.ts      | 72 +++++++++++++++++++
 2 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/packages/survey-core/src/question_matrixdropdownrendered.ts b/packages/survey-core/src/question_matrixdropdownrendered.ts
index 3a45d7e7ae..1792498cec 100644
--- a/packages/survey-core/src/question_matrixdropdownrendered.ts
+++ b/packages/survey-core/src/question_matrixdropdownrendered.ts
@@ -396,7 +396,12 @@ export class QuestionMatrixDropdownRenderedTable extends Base {
     let dataRowIndex = 0;
     for (var i = 0; i < this.rows.length; i++) {
       if (dataRowIndex === index) {
-        if (this.rows[i].isErrorsRow || this.rows[i].isDetailRow) res++;
+        if (this.rows[i].isErrorsRow || this.rows[i].isDetailRow) {
+          res++;
+          if(i + 1 < this.rows.length && this.rows[i + 1].isDetailRow) {
+            res ++;
+          }
+        }
         break;
       }
       res++;
diff --git a/packages/survey-core/tests/question_matrixdynamictests.ts b/packages/survey-core/tests/question_matrixdynamictests.ts
index 806f4d9420..6edaa672db 100644
--- a/packages/survey-core/tests/question_matrixdynamictests.ts
+++ b/packages/survey-core/tests/question_matrixdynamictests.ts
@@ -9781,6 +9781,78 @@ QUnit.test("matrix dynamic detail panel & checkbox valuePropertyName & matrix dy
   matrix1 = <QuestionMatrixDynamicModel>rows[1].getQuestionByName("matrix1");
   assert.deepEqual(matrix1.value, [{ prop1: 3 }], "#2");
 });
+QUnit.test("matrix dynamic & detail panel, add a new row when the last row is expanded, errorLocation: 'bottom', Bug9147", function (assert) {
+  const survey = new SurveyModel({
+    elements: [
+      {
+        type: "matrixdynamic",
+        name: "matrix",
+        errorLocation: "bottom",
+        columns: [
+          {
+            name: "col1",
+            cellType: "text"
+          }
+        ],
+        detailPanelMode: "underRow",
+        detailElements: [
+          {
+            name: "q2",
+            type: "text"
+          }
+        ]
+      }
+    ]
+  });
+  const matrix = <QuestionMatrixDynamicModel>survey.getQuestionByName("matrix");
+  const rendredTable = matrix.renderedTable;
+  const rows = matrix.visibleRows;
+  rows[1].showDetailPanel();
+  assert.equal(rendredTable.rows.length, 2 * 2 + 1, "There are 5 rows");
+  assert.equal(rendredTable.rows[4].isDetailRow, true, "The last row is a detail row");
+  matrix.addRow();
+  assert.equal(rendredTable.rows.length, 3 * 2 + 1, "There are 7 rows");
+  assert.equal(rendredTable.rows[4].isDetailRow, true, "The 5th row is a detail row");
+  assert.equal(rendredTable.rows[5].cells[1].question.name, "col1", "The 6th row is a data row");
+  assert.equal(rendredTable.rows[5].isDetailRow, false, "The 6th row is not a detail row");
+  assert.equal(rendredTable.rows[6].isErrorsRow, true, "The 7th row is an error row");
+  assert.equal(rendredTable.rows[6].isDetailRow, false, "The 7th row is not a detail row");
+});
+QUnit.test("matrix dynamic & detail panel, add a new row when the last row is expanded, errorLocation: 'top' (default), Bug9147", function (assert) {
+  const survey = new SurveyModel({
+    elements: [
+      {
+        type: "matrixdynamic",
+        name: "matrix",
+        columns: [
+          {
+            name: "col1",
+            cellType: "text"
+          }
+        ],
+        detailPanelMode: "underRow",
+        detailElements: [
+          {
+            name: "q2",
+            type: "text"
+          }
+        ]
+      }
+    ]
+  });
+  const matrix = <QuestionMatrixDynamicModel>survey.getQuestionByName("matrix");
+  const rendredTable = matrix.renderedTable;
+  const rows = matrix.visibleRows;
+  rows[1].showDetailPanel();
+  assert.equal(rendredTable.rows.length, 2 * 2 + 1, "There are 5 rows");
+  assert.equal(rendredTable.rows[4].isDetailRow, true, "The last row is a detail row");
+  matrix.addRow();
+  assert.equal(rendredTable.rows.length, 3 * 2 + 1, "There are 7 rows");
+  assert.equal(rendredTable.rows[4].isDetailRow, true, "The 5th row is a detail row");
+  assert.equal(rendredTable.rows[5].isErrorsRow, true, "The 6th row is an error row");
+  assert.equal(rendredTable.rows[6].isDetailRow, false, "The 7th row is not a detail row");
+  assert.equal(rendredTable.rows[6].cells[1].question.name, "col1", "The 7th row is a data row");
+});
 QUnit.test("Totals alingment", function (assert) {
   var json = {
     pages: [