feature: add fixup head into parent

Author: cdammanintopix

src/Resources/Locales/en_US.axaml

@@ -156,6 +156,7 @@
   <x:String x:Key="Text.CommitCM.Reword" xml:space="preserve">Reword</x:String>
   <x:String x:Key="Text.CommitCM.SaveAsPatch" xml:space="preserve">Save as Patch...</x:String>
   <x:String x:Key="Text.CommitCM.Squash" xml:space="preserve">Squash into Parent</x:String>
+  <x:String x:Key="Text.CommitCM.Fixup" xml:space="preserve">Fixup into Parent</x:String>
   <x:String x:Key="Text.CommitDetail.Changes" xml:space="preserve">CHANGES</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Count" xml:space="preserve">changed file(s)</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Search" xml:space="preserve">Search Changes...</x:String>

src/ViewModels/Histories.cs

@@ -341,6 +341,21 @@ public async Task SquashHeadAsync(Models.Commit head)
             }
         }
 
+        public async Task FixupHeadAsync(Models.Commit head)
+        {
+            if (head.Parents.Count == 1)
+            {
+                var parent = await new Commands.QuerySingleCommit(_repo.FullPath, head.Parents[0]).GetResultAsync();
+                if (parent == null)
+                    return;
+
+                var parentMessage = await new Commands.QueryCommitFullMessage(_repo.FullPath, head.Parents[0]).GetResultAsync();
+
+                if (_repo.CanCreatePopup())
+                    await _repo.ShowAndStartPopupAsync(new Squash(_repo, parent, parentMessage));
+            }
+        }
+
         public async Task DropHeadAsync(Models.Commit head)
         {
             var parent = _commits.Find(x => x.SHA.Equals(head.Parents[0]));

src/Views/Histories.axaml.cs

@@ -563,6 +563,17 @@ private ContextMenu CreateContextMenuForSingleCommit(ViewModels.Repository repo,
                         e.Handled = true;
                     };
                     menu.Items.Add(squash);
+
+                    var fixup = new MenuItem();
+                    fixup.Header = App.Text("CommitCM.Fixup");
+                    fixup.Icon = App.CreateMenuIcon("Icons.Fix");
+                    fixup.IsEnabled = commit.Parents.Count == 1;
+                    fixup.Click += async (_, e) =>
+                    {
+                        await vm.FixupHeadAsync(commit);
+                        e.Handled = true;
+                    };
+                    menu.Items.Add(fixup);
                 }
                 else
                 {