Last modified: 2014-10-16 23:43:24 UTC
But not only when typing fast.
Also, after saving a page or discarding an edit, the cursor appears on the Read Mode which could be a related issue, if not will file a separate bug later.
Change 165537 had a related patch set uploaded by Catrope: Followup b8d8a5b: fix stray check for !selection https://gerrit.wikimedia.org/r/165537
Change 165537 merged by jenkins-bot: Followup b8d8a5b: fix stray check for !selection https://gerrit.wikimedia.org/r/165537
The issue of double-typing of characters is resolved but the cursor is still appearing on readmode after saving the page.
Verified the fix for double-typing issue in test2
Verified the fix in production