Fix issue where ignore-whitespace can't be toggled, also move toggle-button to avoid it jumping around

(Additionally, renamed nearby variable from _entireFileLine to _entireFileLines, for clarity and consistency with variable _unifiedLines.)

Author: goran-w

src/ViewModels/DiffContext.cs

@@ -85,23 +85,26 @@ public void OpenExternalMergeTool()
 
         public void CheckSettings()
         {
-            if (Content is TextDiffContext ctx)
-            {
-                var pref = Preferences.Instance;
+            var pref = Preferences.Instance;
 
-                if ((pref.UseFullTextDiff && _info.UnifiedLines != _entireFileLine) ||
-                    (!pref.UseFullTextDiff && _info.UnifiedLines == _entireFileLine) ||
+            if (_info != null)
+            {
+                if ((pref.UseFullTextDiff && _info.UnifiedLines != _entireFileLines) ||
+                    (!pref.UseFullTextDiff && _info.UnifiedLines == _entireFileLines) ||
                     (pref.IgnoreWhitespaceChangesInDiff != _info.IgnoreWhitespace))
                 {
                     LoadContent();
                     return;
                 }
+            }
 
+            if (Content is TextDiffContext ctx)
+            {
                 if (ctx.IsSideBySide() != pref.UseSideBySideDiff)
-                    Content = ctx.SwitchMode();
+                Content = ctx.SwitchMode();
             }
         }
-
+        
         private void LoadContent()
         {
             if (_option.Path.EndsWith('/'))
@@ -114,7 +117,7 @@ private void LoadContent()
             Task.Run(async () =>
             {
                 var pref = Preferences.Instance;
-                var numLines = pref.UseFullTextDiff ? _entireFileLine : _unifiedLines;
+                var numLines = pref.UseFullTextDiff ? _entireFileLines : _unifiedLines;
                 var ignoreWhitespace = pref.IgnoreWhitespaceChangesInDiff;
                 var ignoreCRAtEOL = pref.IgnoreCRAtEOLInDiff;
 
@@ -326,7 +329,7 @@ public bool IsSame(Info other)
             }
         }
 
-        private readonly int _entireFileLine = 999999999;
+        private readonly int _entireFileLines = 999999999;
         private readonly string _repo;
         private readonly Models.DiffOption _option = null;
         private string _fileModeChange = string.Empty;

src/Views/DiffView.axaml

@@ -180,15 +180,6 @@
               <Path Width="12" Height="12" Data="{StaticResource Icons.WordWrap}" Margin="0,2,0,0"/>
             </ToggleButton>
 
-            <ToggleButton Classes="line_path"
-                          Width="28"
-                          IsChecked="{Binding Source={x:Static vm:Preferences.Instance}, Path=IgnoreWhitespaceChangesInDiff, Mode=TwoWay}"
-                          IsVisible="{Binding IsIgnoreWhitespaceVisible, Mode=OneWay}"
-                          ToolTip.Tip="{DynamicResource Text.Diff.IgnoreWhitespace}"
-                          PropertyChanged="OnToggleButtonPropertyChanged">
-              <Path Width="14" Height="14" Stretch="Uniform" Data="{StaticResource Icons.Whitespace}"/>
-            </ToggleButton>
-
             <ToggleButton Classes="line_path"
                           Width="28"
                           IsChecked="{Binding Source={x:Static vm:Preferences.Instance}, Path=ShowHiddenSymbolsInDiffView, Mode=TwoWay}"
@@ -207,6 +198,15 @@
               <Path Width="12" Height="12" Data="{StaticResource Icons.Layout}" Margin="0,2,0,0"/>
             </ToggleButton>
 
+            <ToggleButton Classes="line_path"
+                          Width="28"
+                          IsChecked="{Binding Source={x:Static vm:Preferences.Instance}, Path=IgnoreWhitespaceChangesInDiff, Mode=TwoWay}"
+                          IsVisible="{Binding IsIgnoreWhitespaceVisible, Mode=OneWay}"
+                          ToolTip.Tip="{DynamicResource Text.Diff.IgnoreWhitespace}"
+                          PropertyChanged="OnToggleButtonPropertyChanged">
+              <Path Width="14" Height="14" Stretch="Uniform" Data="{StaticResource Icons.Whitespace}"/>
+            </ToggleButton>
+
             <Button x:Name="BtnOpenExternalMergeTool"
                     Classes="icon_button"
                     Width="28"