When you follow a "Source" link on a post's /revisions (versions) page and copy and paste it the line endings are doubled. (Windows 10 Firefox)
(It happens in and out of code blocks. My example happens to be just a code block.)
When I paste the cut text into an an online character identifier there are double CRs & a final LF.
A code block that includes fences to cut & paste:
```
1
2
3
4
```
The revisions page version 2 Source page of this post looks like this code block looks (same as above):
```
1
2
3
4
```
Screenshot from Source page (looks the same as above):
Cut & paste into editor from Source page:
```
1
2
3
4
```
I have never not seen this happen, and I first saw it at least several years ago.
This also happens pasting into a Windows Notepad .txt.
