Link will failed if the target slide having vertical child slides

[tonyduke-sjtu]

1. set [link](#target1) on source slide
2. The anchor was set by code as {.slide id="target1"} on target1 slide
3. target1 have 1 vertical child. so it shows like target1 and target1/2
4. Click link and redirect to the title page.
5. Change the vertical child to a sibling slide, so it shows like target1 and target2
6. the link will works fine.

more try:
check the original doc from reveal.js.
I tried add a /, like this:[link](#/target1). then failed
tried add a subpage sequence, like this: [link](#target1/1). then failed again
tried add both, like this: [link](#/target1/1),[link](#/target1/2), failed