FIX: Renaming a sheet with the same name doesn't do anything

Fixes #103

base/src/test/user_model/test_rename_sheet.rs

@@ -9,6 +9,13 @@ fn basic_rename() {
     assert_eq!(model.get_worksheets_properties()[0].name, "NewSheet");
 }
 
+#[test]
+fn rename_with_same_name() {
+    let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
+    model.rename_sheet(0, "Sheet1").unwrap();
+    assert_eq!(model.get_worksheets_properties()[0].name, "Sheet1");
+}
+
 #[test]
 fn undo_redo() {
     let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();

base/src/user_model/common.rs

@@ -457,6 +457,9 @@ impl UserModel {
     /// * [Model::rename_sheet_by_index]
     pub fn rename_sheet(&mut self, sheet: u32, new_name: &str) -> Result<(), String> {
         let old_value = self.model.workbook.worksheet(sheet)?.name.clone();
+        if old_value == new_name {
+            return Ok(());
+        }
         self.model.rename_sheet_by_index(sheet, new_name)?;
         self.push_diff_list(vec![Diff::RenameSheet {
             index: sheet,