Steps to reproduce:
- Go to https://en.wikipedia.org/w/index.php?title=Keith_B._Alexander&oldid=977666541
- Copy the wikitext of the page into your sandbox for demonstration purposes (the bug is not isolated to the sandbox)
- View this page in your sandbox from a mobile phone browser (not the Wikipedia app), and notice that there is some extra space (line break) at the end of the "Amazon appointment" section
- Click edit on the "Amazon appointment" section and select the visual editor
- Attempt to remove the extra line breaks by tapping on the blank area beneath the text (about an inch or more below the paragraph to make sure you do not miss a line), then pressing the backspace button. You will have to press the backspace button twice to delete each empty line, and there appears to be two extraneous line breaks, so you will need to press backspace a total of four times before it brings your cursor to the last reference in the paragraph.
- Save/review the edit.
Actual results:
The paragraph that was untouched is duplicated beneath the original (although now there is no extra space below the duplicate). Also, in place what were the references, the duplicate has two snowmen characters "☃☃"
Expected results:
The blank space at the end of the section is removed.
Example diffs where this happened to me on English Wikipedia (and the next edit is me correcting the text by deleting the duplicate):