Can we just stop using wgTitle and use wgPageName instead? Quoting from the docs:

wgTitle - "The page title. May contain blanks, does contain neither underscores nor namespace names."
wgPageeName - "The full name of the page, including the localized namespace name, if the namespace has a name (the main namespace (number 0) doesn't), and with blanks replaced by underscores."

wgPageName does use localized namespaces as noted above, but it should be internally consistent.

I'm not sure what the goal of the querystring suggestion is. Right now, users get "assigned" a task, but they don't have to edit immediately. They can wander around then come back and make their task edit. It seems like this would break that.

wgPageName seems easier than trying to parse the title of the returnto link.

swalling wrote:

This extension is no longer deployed, and openTask is no longer be relied on.

However, in GettingStarted, we ended up using the equivalent of:

new mw.Title( mw.config.get( 'wgPageName' ) ).getPrefixedText()

to solve the problem (the openTask cookie is still used, but the values have changed somewhat).