An original code (correct rendering):https://github.com/magento/magento2/blob/720667e/lib/internal/Magento/Framework/DB/Transaction.php#L49-L60
A email with the code (wrong rendering: extra empty lines are added, the screenshot is taken in the GMail web interface):
「いいね！」 2
sam
2016 年 4 月 28 日午前 12:56
2
Are you sure there are empty lines there and its not simply that the CSS is a bit off?
「いいね！」 1
The line breaks between the <li> tags are preserved because the code is inside the <pre>
「いいね！」 2
Now it became even worse: the violet background now covers only a part of the code block:
