[tag:bug]

Copying quoted text from Markdown mode into a text editor like Visual Studio Code and back invisibly breaks the Markdown to insert extra line breaks between the lines of the quote.  Toggling back and forth between rich text and Markdown reveals the extra line breaks.

![Copy-pasting between windows inserting linebreaks](https://i.sstatic.net/BGzWM.gif)

This isn't a contrived scenario: I often compose longer posts in a separate text editor so that I don't lose them if something happens to the browser tab.