Merge pull request #4236 from sdoroff/datagrid-edit-sizing

Fix DataGrid row height issue

src/Avalonia.Controls.DataGrid/DataGrid.cs

@@ -3920,6 +3920,8 @@ namespace Avalonia.Controls
                     dataGridColumn: CurrentColumn,
                     dataGridRow: EditingRow,
                     dataGridCell: editingCell);
+
+                EditingRow.InvalidateDesiredHeight();
             }
 
             // We're done, so raise the CellEditEnded event

src/Avalonia.Controls.DataGrid/DataGridRow.cs

@@ -767,6 +767,11 @@ namespace Avalonia.Controls
             }
         }
 
+        internal void InvalidateDesiredHeight()
+        {
+            _cellsElement?.InvalidateDesiredHeight();
+        }
+
         internal void ResetGridLine()
         {
             _bottomGridLine = null;

src/Avalonia.Controls.DataGrid/Primitives/DataGridCellsPresenter.cs

@@ -299,6 +299,11 @@ namespace Avalonia.Controls.Primitives
             DesiredHeight = 0;
         }
 
+        internal void InvalidateDesiredHeight()
+        {
+            DesiredHeight = 0;
+        }
+
         private bool ShouldDisplayCell(DataGridColumn column, double frozenLeftEdge, double scrollingLeftEdge)
         {
             if (!column.IsVisible)