List of steps to reproduce (step by step, including full links if applicable):
- Create an account with quotes in the username. Examples: [[User:R'n'B]], [[User:RoySmith-testing'with'quotes]].
- Try to login on an iPhone using Chrome or Safari on the desktop site.
Actual Results (what happens?):
- Login fails
Expected Results (what should have happened?):
- Login does not fail
See [[WP:VPT#Can't log in with Safari on iOS]] on enwiki for background.
My hunch is this is actually a client-side issue, but reporting it for tracking purposes.