bogus alert when page contents have not changed
Seen in IE9 on beta labs enwiki:
Open any editable page in IE9 (and probably in earlier versions of IE).
Click the Edit tab.
Click the Read tab.
Upon doing this the user often but not always sees an alert saying "Are you sure you want to leave this page?..." as if the page had been edited, but the contents of the page have not changed.
This is a significant cause of flaky browser test automation behavior, for example https://wmf.ci.cloudbees.com/job/browsertests-en.wikipedia.beta.wmflabs.org-windows-internet_explorer_9/17/
I confirmed that this behavior happens when clicking Edit/Read manually as well.
Version: 1.22.0
Severity: normal
OS: Windows 7
Platform: PC
Attached: