copy_worksheet failes on files with merged cells
*Created originally on Bitbucket by [steven somersbury (Liam Sanders)](https://bitbucket.org/%7B026e1b96-49c2-4f9b-96ab-4e2200c83817%7D/)* **Env:** Python 3.8.1 with openpyxl 3.0.4 installed. There seems to be some internal difference between programatically created merged cells and merged cells loaded from a file when copying worksheets ```python from openpyxl import Workbook, load_workbook # This works fine wb = Workbook() ws = wb.active ws.merge_cells("A1:E1") wb.copy_worksheet(ws) wb.save("Result.xlsx") # This breaks with a min_col error wb = load_workbook("TestMergedCopy.xlsx") newSheet = wb.copy_worksheet(wb["Sheet1"]) wb.save("Result2.xlsx") ``` ”TestMergedCopy.xlsx” is a empty file with cells A1:E1 merged.
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