Cannot navigate from /a/[id] to /b/[id]

[thgh]

Repro: https://github.com/thgh/sapper-template/tree/repro-606
Steps:

1. Visit https://todo-xflcnzulor.now.sh/b/same
2. Notice page: b/same
3. Click link a/same
4. Notice page is still b/same (expected a/same)
5. Refresh
6. Page is now a/same (correct)

There is two routes

• /a/[id]/index.svelte
• /b/[id]/index.svelte

It seems sapper does not detect when navigating between both.

[cudr]

sapper/runtime/src/app/app.ts

Line 257 in 7be7e1e

if (!session_dirty && current_branch[i] && current_branch[i].segment === segment) return current_branch[i];

current_branch[i].segment === segment

In this case segments are equals, so app don't change page

[thgh]

That code is never reached, it short circuits because part === null

sapper/runtime/src/app/app.ts

Lines 250 to 252 in 7be7e1e

	branch = await Promise.all(route.parts.map(async (part, i) => {
	props.segments[l] = segments[i + 1]; // TODO make this less confusing
	if (!part) return null;