fix: text diff editor crash when clicking selected text in LOCAL CHANGES view

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/MergeConflictEditor.axaml.cs

@@ -408,7 +408,7 @@ private void OnTextViewPointerChanged(object sender, PointerEventArgs e)
             if (DataContext is not ViewModels.MergeConflictEditor vm)
                 return;
 
-            if (sender is not TextView view)
+            if (sender is not TextView { VisualLinesValid: true } view)
                 return;
 
             UpdateSelectedChunkPosition(vm, e.GetPosition(view).Y + view.VerticalOffset);
@@ -419,7 +419,7 @@ private void OnTextViewPointerWheelChanged(object sender, PointerWheelEventArgs
             if (DataContext is not ViewModels.MergeConflictEditor vm)
                 return;
 
-            if (sender is not TextView view)
+            if (sender is not TextView { VisualLinesValid: true } view)
                 return;
 
             var y = e.GetPosition(view).Y + view.VerticalOffset;

src/Views/TextDiffView.axaml.cs

@@ -1024,6 +1024,9 @@ protected override void UpdateSelectedChunk(double y)
                 return;
 
             var view = TextArea.TextView;
+            if (!view.VisualLinesValid)
+                return;
+
             var selection = TextArea.Selection;
             if (!selection.IsEmpty)
             {
@@ -1212,6 +1215,9 @@ protected override void UpdateSelectedChunk(double y)
                 return;
 
             var view = TextArea.TextView;
+            if (!view.VisualLinesValid)
+                return;
+
             var lines = IsOld ? diff.Old : diff.New;
             var selection = TextArea.Selection;
             if (!selection.IsEmpty)