"Hide whitespace diffs" option doesn't persist across pages if linked with "?w=1"

[jfdoming]

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If someone gives you a link to a PR files page with ?w=1 at the end, you will see whitespace changes disabled on this page. However, if you navigate to another back and manually click back onto the pull request, or more crucially, click into the commit view, the ?w=1 status is not persisted. I would expect this setting to persist everywhere until turned off.

What I'm actually trying to do: I want to provide reviewers a link to "review by commit" with whitespace changes disabled if there are a lot of unnecessary whitespace changes. However, if I do so, only the first commit has changes disabled; all subsequent commits (after clicking the "next" button) have them enabled again.