Hi EPPlus developers,
a fix from 01 Sept 2015 (65115680ca04) on ___ExcelRangeBase.AddComment___ invoked some deeper problem, which existed already before.
Creating a Comment with an empty Author
```
package.Workbook.Worksheets.First().Cells["A1"].AddComment("Text", String.Empty);
```
will lead to a cell with no __authorId__ attribute
```
<comments xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<authors/>
<commentList>
<comment ref="D1" >
<text>
...
```
This is not allowed by specification. See ___18.7.1 author (Author)___
> This element holds a string representing the name of a single author of comments. Every comment shall have an author.
Excel does not want to open these files either and repares them by deleting the whole comment tag. I think this is not crucial, if you will allow emty Author again. By the way, if ___Author___ property of ___ExcelComment___ class is read, when it was never set before - it throws a NullReferenceException.
Comments: Perhaps EPPlus can throw an __ArgumentException__ if a null/empty author value is used? That will make debugging much easier :-)
a fix from 01 Sept 2015 (65115680ca04) on ___ExcelRangeBase.AddComment___ invoked some deeper problem, which existed already before.
Creating a Comment with an empty Author
```
package.Workbook.Worksheets.First().Cells["A1"].AddComment("Text", String.Empty);
```
will lead to a cell with no __authorId__ attribute
```
<comments xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<authors/>
<commentList>
<comment ref="D1" >
<text>
...
```
This is not allowed by specification. See ___18.7.1 author (Author)___
> This element holds a string representing the name of a single author of comments. Every comment shall have an author.
Excel does not want to open these files either and repares them by deleting the whole comment tag. I think this is not crucial, if you will allow emty Author again. By the way, if ___Author___ property of ___ExcelComment___ class is read, when it was never set before - it throws a NullReferenceException.
Comments: Perhaps EPPlus can throw an __ArgumentException__ if a null/empty author value is used? That will make debugging much easier :-)