From 757c64e49ca514a36409eb7d235971e6c59ea0e6 Mon Sep 17 00:00:00 2001
From: leo <longshuang@msn.cn>
Date: Thu, 26 Nov 2020 12:47:24 +0800
Subject: [PATCH] fix<Diff, Blame>: check scroller before use it

---
 src/UI/Blame.xaml.cs      |  2 +-
 src/UI/DiffViewer.xaml.cs | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/UI/Blame.xaml.cs b/src/UI/Blame.xaml.cs
index d9df77aa..11630441 100644
--- a/src/UI/Blame.xaml.cs
+++ b/src/UI/Blame.xaml.cs
@@ -171,7 +171,7 @@ namespace SourceGit.UI {
             var minWidth = total - offset;
 
             var scroller = GetVisualChild<ScrollViewer>(blame);
-            if (scroller.ComputedVerticalScrollBarVisibility == Visibility.Visible) minWidth -= 8;
+            if (scroller != null && scroller.ComputedVerticalScrollBarVisibility == Visibility.Visible) minWidth -= 8;
 
             blame.Columns[1].MinWidth = minWidth;
             blame.Columns[1].Width = DataGridLength.SizeToCells;
diff --git a/src/UI/DiffViewer.xaml.cs b/src/UI/DiffViewer.xaml.cs
index faa1f240..287e20a0 100644
--- a/src/UI/DiffViewer.xaml.cs
+++ b/src/UI/DiffViewer.xaml.cs
@@ -466,12 +466,16 @@ namespace SourceGit.UI {
             if (e.VerticalChange != 0) {
                 foreach (var editor in editors) {
                     var scroller = GetVisualChild<ScrollViewer>(editor);
-                    if (scroller.VerticalOffset != e.VerticalOffset) scroller.ScrollToVerticalOffset(e.VerticalOffset);
+                    if (scroller != null && scroller.VerticalOffset != e.VerticalOffset) {
+                        scroller.ScrollToVerticalOffset(e.VerticalOffset);
+                    }
                 }
             } else {
                 foreach (var editor in editors) {
                     var scroller = GetVisualChild<ScrollViewer>(editor);
-                    if (scroller.HorizontalOffset != e.HorizontalOffset) scroller.ScrollToHorizontalOffset(e.HorizontalOffset);
+                    if (scroller != null && scroller.HorizontalOffset != e.HorizontalOffset) {
+                        scroller.ScrollToHorizontalOffset(e.HorizontalOffset);
+                    }
                 }
             }
         }
@@ -486,6 +490,8 @@ namespace SourceGit.UI {
 
             var grid = editors[0];
             var scroller = GetVisualChild<ScrollViewer>(grid);
+            if (scroller == null) return;
+
             var firstVisible = (int)scroller.VerticalOffset;
             var firstModeEnded = false;
             var first = grid.Items[firstVisible] as ChangeBlock;
@@ -512,6 +518,8 @@ namespace SourceGit.UI {
 
             var grid = editors[0];
             var scroller = GetVisualChild<ScrollViewer>(grid);
+            if (scroller == null) return;
+
             var firstVisible = (int)scroller.VerticalOffset;
             var firstModeEnded = false;
             var first = grid.Items[firstVisible] as ChangeBlock;