URL: https://github.com/

Browser / Version: Firefox 68.0
Operating System: Windows 10
Tested Another Browser: Yes

Problem type: Something else
Description: GitHub "Quote Reply" adds extra empty lines in Firefox, removes empty lines in Edge
Steps to Reproduce:
STR:

1. Load an existing GitHub issue.
2. Select "Quote Reply" on a comment that has multiple paragraphs or newlines.

RESULT:

• Firefox will prepend two empty > lines before the quoted reply. I tested Firefox 66 Release and 68 Nightly.
• Edge will remove empty lines between paragraphs.
• Chrome does the right thing. It doesn't add or remove any empty lines.

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