tour: redirect for old-style /#NNN links

[mikeyhill]

Context: https://tour.golang.org/#1

Tour is blank in both FF and Chrome on osx. All plugins disabled (had adblock, ghostery, flash-control). Can't seem to view this tutorial. Let me know if you need more info.

[dominikh]

Can confirm. JS error:

Error: Failed to execute 'replaceState' on 'History': A history state object with URL 'https://tour.golang.org1/' cannot be created in a document with origin 'https://tour.golang.org'. (script.js:507)
    at Error (native)
    at vc.f.url (https://tour.golang.org/script.js:477:28)
    at Ic.$get (https://tour.golang.org/script.js:506:6)
    at Object.d [as invoke] (https://tour.golang.org/script.js:473:127)
    at https://tour.golang.org/script.js:474:298
    at c (https://tour.golang.org/script.js:471:479)
    at Object.d [as invoke] (https://tour.golang.org/script.js:472:111)
    at https://tour.golang.org/script.js:474:298
    at c (https://tour.golang.org/script.js:471:479)
    at Object.d [as invoke] (https://tour.golang.org/script.js:472:111)

[minux]

where did you get such a link? it's out of date. https://tour.golang.org works correctly.

[dominikh]

I think there should be backwards-compatibility for those links. They've been used and shared for years to point to specific slides of the tour.

I understand that the numbering of slides might've changed, but then it should at least fall back gracefully, not break outright.

[adg]

@campoy we could pretty easily set up a map of old # fragments to their modern equivalents (or close enough). A blank page is bad, at least.

[gopherbot]

CL https://golang.org/cl/12775 mentions this issue.