This is, in particular, a problem for PhpSpreadsheet. See https://github.com/PHPOffice/PhpSpreadsheet/issues/1164. TCPDF thinks that there can be 0, 1, 2, or 3 components to shorthand border style, but there can be more, e.g. !important. Logic is rearranged to allow for more than 3. A new example file is added to demonstrate that the fix works correctly.
This is, in particular, a problem for PhpSpreadsheet. See https://github.com/PHPOffice/PhpSpreadsheet/issues/1164. TCPDF thinks that there can be 0, 1, 2, or 3 components to shorthand border style, but there can be more, e.g. !important. Logic is rearranged to allow for more than 3. A new example file is added to demonstrate that the fix works correctly.