Word can not open docx due to incorrect serialization for CT_Point2D when used in CT_Anchor for CT_Drawing

[paulhahn-rapiddata]

NPOI Version

2.7.2

File Type

• XLSX
• XLS
• DOCX
• XLSM
• OTHER

Reproduce Steps

1. Add drawing to your document
2. anchor the drawing
3. Set CT_Anchor.simplePos to an instance of CT_Point2D

This will create a tag:
<a:simplePos x="0" y="0" />
as child of the anchor tag.

Issue Description

The modified document can not be opened by word. If manually editing the tag to this:
<wp:simplePos x="0" y="0" />
word will be able to open and display the document.

I assume that this a tag should be a wp tag instead, but i am not a docx expert.
Here is the NPOI code line that would need the change from a to wp:

npoi/OpenXmlFormats/Drawing/BaseTypes.cs

Line 274 in af9bd4f

sw.Write(string.Format("<a:{0}", nodeName));

I tried to circumvent the issue by setting simplePos to null, which generates the anchor without the tag. However, this will also not be accepted by word.

This means that effectively it is not possible to anchor a drawing with NPOI, potentially other elements as well.

[tonyqus]

Can you create a PR for this?