fix: submodule diff missing commit message

src/Models/DiffResult.cs

@@ -587,10 +587,16 @@ namespace SourceGit.Models
         public string New { get; set; } = string.Empty;
     }
 
+    public class SubmoduleRevision
+    {
+        public Commit Commit { get; set; } = null;
+        public string FullMessage { get; set; } = string.Empty;
+    }
+
     public class SubmoduleDiff
     {
-        public Commit Old { get; set; } = null;
+        public SubmoduleRevision Old { get; set; } = null;
-        public Commit New { get; set; } = null;
+        public SubmoduleRevision New { get; set; } = null;
     }
 
     public class DiffResult

src/ViewModels/DiffContext.cs

@@ -131,12 +131,12 @@ namespace SourceGit.ViewModels
                             if (line.Type == Models.TextDiffLineType.Added)
                             {
                                 var sha = line.Content.Substring("Subproject commit ".Length);
-                                submoduleDiff.New = new Commands.QuerySingleCommit(submoduleRoot, sha).Result() ?? new Models.Commit() { SHA = sha };
+                                submoduleDiff.New = QuerySubmoduleRevision(submoduleRoot, sha);
                             }
                             else if (line.Type == Models.TextDiffLineType.Deleted)
                             {
                                 var sha = line.Content.Substring("Subproject commit ".Length);
-                                submoduleDiff.Old = new Commands.QuerySingleCommit(submoduleRoot, sha).Result() ?? new Models.Commit() { SHA = sha };
+                                submoduleDiff.Old = QuerySubmoduleRevision(submoduleRoot, sha);
                             }
                         }
                         rs = submoduleDiff;
@@ -219,6 +219,22 @@ namespace SourceGit.ViewModels
             return size > 0 ? (new Bitmap(stream), size) : (null, size);
         }
 
+        private Models.SubmoduleRevision QuerySubmoduleRevision(string repo, string sha)
+        {
+            var commit = new Commands.QuerySingleCommit(repo, sha).Result();
+            if (commit != null)
+            {
+                var body = new Commands.QueryCommitFullMessage(repo, sha).Result();
+                return new Models.SubmoduleRevision() { Commit = commit, FullMessage = body };
+            }
+
+            return new Models.SubmoduleRevision()
+            {
+                Commit = new Models.Commit() { SHA = sha },
+                FullMessage = string.Empty,
+            };
+        }
+
         private static readonly HashSet<string> IMG_EXTS = new HashSet<string>()
         {
             ".ico", ".bmp", ".jpg", ".png", ".jpeg"

src/Views/DiffView.axaml

@@ -151,9 +151,9 @@
                   <Border IsVisible="{Binding Old, Converter={x:Static ObjectConverters.IsNotNull}}">
                     <ContentControl Content="{Binding Old}">
                       <ContentControl.DataTemplates>
-                        <DataTemplate DataType="m:Commit">
+                        <DataTemplate DataType="m:SubmoduleRevision">
                           <Border Margin="0,0,0,8" BorderThickness="1" BorderBrush="{DynamicResource Brush.Border1}" Background="{DynamicResource Brush.Window}">
-                            <v:CommitBaseInfo MaxHeight="256" Margin="0,0,0,4" CanNavigate="False" Content="{Binding}"/>
+                            <v:CommitBaseInfo MaxHeight="256" Margin="0,0,0,4" CanNavigate="False" Content="{Binding Commit}" Message="{Binding FullMessage}"/>
                           </Border>
                         </DataTemplate>
                       </ContentControl.DataTemplates>
@@ -167,7 +167,7 @@
                   <Path Width="16" Height="16" Data="{StaticResource Icons.DoubleDown}" HorizontalAlignment="Center" IsVisible="{Binding Old, Converter={x:Static ObjectConverters.IsNotNull}}"/>
 
                   <Border Margin="0,8,0,0" BorderThickness="1" BorderBrush="Green" Background="{DynamicResource Brush.Window}">
-                    <v:CommitBaseInfo MaxHeight="256" Margin="0,0,0,4" CanNavigate="False" Content="{Binding New}"/>
+                    <v:CommitBaseInfo MaxHeight="256" Margin="0,0,0,4" CanNavigate="False" Content="{Binding New.Commit}" Message="{Binding New.FullMessage}"/>
                   </Border>
                 </StackPanel>
               </ScrollViewer>
@@ -239,7 +239,7 @@
                             UseSideBySideDiff="{Binding Source={x:Static vm:Preference.Instance}, Path=UseSideBySideDiff, Mode=OneWay}"/>
           </DataTemplate>
 
-          <!-- No or only EOL changes -->
+          <!-- Empty or only EOL changes -->
           <DataTemplate DataType="m:NoOrEOLChange">
             <StackPanel Orientation="Vertical" VerticalAlignment="Center">
               <Path Width="64" Height="64" Data="{StaticResource Icons.Check}" Fill="{DynamicResource Brush.FG2}"/>