Phpspreadsheet: Invalid character found in sheet title

[dangthanhnhat]

This is:

- [ ] a bug report
- [ ] a feature request
- [ ] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

Which versions of PhpSpreadsheet and PHP are affected?

1.7.0

My sheet title contain "/" e.g "test Title/B2" and it cause this error.
I don't know what else character cause this error too.
How do I solved it. User should be input what ever they want.
Sorry for my bad english

[MarkBaker]

No! Users ____shouldn't____ be able to input whatever they want; because MS Excel has rules for the naming of worksheets:

• Two worksheets cannot have the same name, regardless of upper or lowercase. Excel will return the error: Cannot rename a sheet to the same name as another sheet, a referenced object library or a workbook referenced by Visual Basic.
• A worksheet name cannot cannot exceed 31 characters.
• A worksheet name cannot be left blank.
• A worksheet cannot be named history in either lower or uppercase. History is reserved by Excel for tracking changes between shared workbooks.
• Any letter from A to Z, and any number from 0 to 9 can be used.
• The following character symbols are allowed, but if the worksheet name contains a blank or any of these characters, the name must be wrapped in single quotes when manually entering formulas to link worksheet data.
  
  
  
  • ~ ! @ # $ % ^ & ( ) - _ = + { } | ; : , < . >
  
  
  • The apostrophe (' ) cannot be used at the beginning or end of a worksheet name, but can be used in the middle of a name.
  
  
  • The following characters are forbidden for use when naming worksheets. Excel will not even allow you to type them:
  
  
  • \ / ? * [ ] :