fix: for Fixup commits, message should not append to the target commit

Signed-off-by: leo <[email protected]>

Author: love-linger

src/ViewModels/InteractiveRebase.cs

@@ -362,8 +362,19 @@ private void UpdateItems()
                     continue;
                 }
 
-                if (item.Action == Models.InteractiveRebaseAction.Fixup ||
-                    item.Action == Models.InteractiveRebaseAction.Squash)
+                if (item.Action == Models.InteractiveRebaseAction.Fixup)
+                {
+                    item.IsFullMessageUsed = false;
+                    item.ShowEditMessageButton = false;
+                    item.PendingType = hasPending ? Models.InteractiveRebasePendingType.Pending : Models.InteractiveRebasePendingType.Last;
+                    item.FullMessage = item.OriginalFullMessage;
+                    item.IsMessageUserEdited = false;
+
+                    hasPending = true;
+                    continue;
+                }
+
+                if (item.Action == Models.InteractiveRebaseAction.Squash)
                 {
                     item.IsFullMessageUsed = false;
                     item.ShowEditMessageButton = false;